Solar Question

Submitted: Wednesday, Apr 14, 2010 at 02:40
ThreadID: 77704 Views:5997 Replies:8 FollowUps:114
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Im set up with 2x80w panels & 2 x 110 deep cycle batteries in the 23'roadstar
i have a 57ah second battery system in the GQ for the 80litre waeco
Which with 57ah doesnt last long when im stopped for a few days
Now my question .im thinking of putting a solar panel on the roof racks of the trol
what size panel would be recomended & where would i connect it too a regulator or directly to the battery ???
ill be useing the waeco mainly as a freezer
\ warren aka aussichef
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Reply By: blue one - Wednesday, Apr 14, 2010 at 06:23

Wednesday, Apr 14, 2010 at 06:23
Warren,
That would be the biggest panel you can fit / afford and through a regulator to the battery.

Cheers

Steve
AnswerID: 412846

Reply By: Member - Boobook - Wednesday, Apr 14, 2010 at 06:35

Wednesday, Apr 14, 2010 at 06:35
Assuming you don't have too much load in the van, you probably have all you need.

If you connect the third battery in the GQ to the two in the van - hey presto, 277AH charged by 160W of panels.

If you do need more then add another panel to the two you already have and you don't need a second reg.

Make sure the cable is as thick as you can and preferably 3 AWG or more. That way you will minimise the voltage drop.

I would be surprised if you don;t have enough capacity. What do you run in the van now?
AnswerID: 412847

Follow Up By: Member - Toyocrusa (NSW) - Wednesday, Apr 14, 2010 at 06:49

Wednesday, Apr 14, 2010 at 06:49
23ft van would be running a decent size main fridge, Waeco, TV, lights etc. Would need at least 4 80watt panels, especially in the Southern states in winter. Bob.
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FollowupID: 682877

Follow Up By: Member - Boobook - Wednesday, Apr 14, 2010 at 06:53

Wednesday, Apr 14, 2010 at 06:53
Surely a decent sized fridge would be gas yeah?
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FollowupID: 682878

Follow Up By: Member - aussichef (SA) - Wednesday, Apr 14, 2010 at 09:21

Wednesday, Apr 14, 2010 at 09:21
yes Bob im going to add a cpl more panels i think to the caravan

Boobook
yes the Dometic fridge works on gas when needed
warren aka aussichef
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FollowupID: 682887

Follow Up By: Member - Boobook - Wednesday, Apr 14, 2010 at 10:29

Wednesday, Apr 14, 2010 at 10:29
Aussichef, one other issue I just noticed and for you to watch is that the 80l Waeco is very power hungry. It will use something like 64 Amphours per day. That means that you should have a 140ish AH battery just to support the fridge. ( based on 50% discharge and 24 hours use per charge) It also means that the fridge alone will need about 200Watts of solar panels to keep a charge if you aren't charging by driving.


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FollowupID: 682897

Reply By: Mandrake's Solar Power- Wednesday, Apr 14, 2010 at 06:56

Wednesday, Apr 14, 2010 at 06:56
Aussichef .

My setup has a 140 w panel on the Jeep roof attached to a 100aH AGM in the rear which runs a Waeco 50 .. This arrangement works well until we get 4-5 days of cloudy weather !! However I also have a 50 watt panel on the camper lid which can now be hooked into the fridge battery and should give that little bit extra when on a trip .. I also have a 2X50w portable unit to further add to the input if needed .. ( the benefit of owning the company !! )

Any chance of changing that 57 aH to something a bit bigger ? that might also help ..

Cheers

Steve

AnswerID: 412850

Follow Up By: Member - aussichef (SA) - Wednesday, Apr 14, 2010 at 09:19

Wednesday, Apr 14, 2010 at 09:19
Unfortunatly in the GQ there isnt enough room for a bigger second battery
in the engine bay
i have a 100ah battery behind the car fridge but im having trouble getting the charge thru to it. Im using 6mm cable but weather i need a bigger alternator i dont know as a mechanic i make a great chef lol
warren aka aussichef
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FollowupID: 682886

Follow Up By: Maîneÿ . . .- Wednesday, Apr 14, 2010 at 09:29

Wednesday, Apr 14, 2010 at 09:29
aussichef,
change your "6mm cable" to 10mm sq and see what happens

Maîneÿ . . .
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FollowupID: 682888

Follow Up By: Member - Scrubby (VIC) - Wednesday, Apr 14, 2010 at 19:30

Wednesday, Apr 14, 2010 at 19:30
aussichef,
Have you considered a DC-DC charger ?

I charge my auxiliary battery @ 14.4v ( can be set to suit battery up to 14.8v ) and up to 50 amps, depending upon SOC of aux battery.
Mine is connected to the starter battery but others can be direct from alternator.

Regards,

Scrubby
I don`t know where i`m going but i`m enjoying the journey.

Member
My Profile  My Blog  My Position  Send Message

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FollowupID: 682959

Follow Up By: oldtrack123 - Saturday, Apr 17, 2010 at 10:57

Saturday, Apr 17, 2010 at 10:57
Hi Warren
No you should not need a bigger alternator, but what voltage does your alternator charge to ??
Some later vechicles do not fully charge battery to 13.8< 14.4v
Cable size & bad joints can also be a problem.
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FollowupID: 683357

Reply By: Alloy c/t - Wednesday, Apr 14, 2010 at 10:30

Wednesday, Apr 14, 2010 at 10:30
The 80lt Waeco will chew thru your 57amp hr batt in no time , after 6yrs of having the 80 I can tell you that it uses 64 amp hrs per 24hrs when used as a fridge/freezer with the freezer section set at -18c , when using as all freezer add another 30/50% of power drain even if only opened once per day ,,
AnswerID: 412869

Follow Up By: Fatso - Wednesday, Apr 14, 2010 at 19:37

Wednesday, Apr 14, 2010 at 19:37
How do you think he would go by upgrading to a more efficient fridge? Maybe a trailblazer or something similar.
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FollowupID: 682963

Follow Up By: Steve and Viv - Wednesday, Apr 14, 2010 at 23:31

Wednesday, Apr 14, 2010 at 23:31
The Danfross compressors in the Waecos are one of the most efficient you can get. Most of the better ones run these. I would turn it down from -18 to -14 for a start and then ask your self, why the freezer. We cryovac and get two weeks out of a steak at -1 in one of our fridges....Unless you need to have ice cream with you or ice blocks for the G&T - what's the need?
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FollowupID: 682999

Follow Up By: Alloy c/t - Thursday, Apr 15, 2010 at 07:59

Thursday, Apr 15, 2010 at 07:59
Steve+ Viv , Whats the need ? Why do you have a freezer at home ? As for Cryovac it is great but it is NOT the be all and end all , now if you solid freeze your cryovac and keep it in the freezer it will last indefinitly , , Danfoss most efficient ? Not the BD50 as used in the 80/110lt Waecos , Engle of compareable size uses 40% less power every 24hrs. Drop temp from -18 to -14 =nil power savings in the Waeco 80 as the colder temp with a full freezer section acts like a cold bank ,ergo less compressor on time = less power used.
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FollowupID: 683014

Follow Up By: Faulic_McVitte - Friday, Apr 16, 2010 at 19:07

Friday, Apr 16, 2010 at 19:07
Alloy there is no difference in power consumption between the Sawa Fuji compressor used by Engel or the Danfoss compressor used in the majority of other brands of portable fridge. Engel did a great job of giving you the big hypodermic needle loaded with bad power consumption vibes. Fact is the Mitsubishi 12/24V rotary compressor is the most efficient only by around 5%.
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FollowupID: 683256

Follow Up By: Steve and Viv - Friday, Apr 16, 2010 at 20:16

Friday, Apr 16, 2010 at 20:16
Alloy CT. Clearly what I consider camping verse what you do are two different things, fair enough. I don't try to emulate my home fridge freezer out at camp. I also don't need food to last indefinitely, maybe the OP does, and yes we go away for a long time (last trip was 6 Months on the road so I do have an idea what it's like to have to plan. Second you are just wrong if you think that there are no saving by not trying to freeze so low, ie, -14 v -18. It takes a lot for a fridge to keep food frozen lower.You may freeze your food at home before you go but it starts to equalize asap and the difference in ambient temperature will dictate how hard it has to work to maintain your desired temp. If that set temp is closer to the ambient then the less it will cycle. A bit like the over night scenario. Een different foods will make it run longer to reach your set temp. Water is one of the worst to freeze.

So again to the OP. Work out how long your needing food to last and in a combination with the cryo you may find that from frozen to your last day you can run it at -5.Play around at home which is what I do so I know how many days it takes for things to defrost. As I posted above though. If you need ice cream then you'll need the -18 and that's fair enough. we didn't and the kids were happy to wait for a week on our 6 Months trip away until we got to the next road house or whatever

I maybe be missing your point ?
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FollowupID: 683268

Follow Up By: Alloy c/t - Saturday, Apr 17, 2010 at 06:42

Saturday, Apr 17, 2010 at 06:42
Faulic , there is a difference between the Danfoss BD35 as used by most other brands of portable fridges and the smaller Waecos ,,BD50 as used in the 80/110 lt Waeco's , Engle however use the same SawaFuji throughout their range , ergo the power consumption of an 80lt Waeco .
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FollowupID: 683324

Reply By: Maîneÿ . . .- Thursday, Apr 15, 2010 at 08:27

Thursday, Apr 15, 2010 at 08:27
aussichef,
Your question is: "im thinking of putting a solar panel on the roof racks of the trol, what size panel would be recomended & where would i connect it too a regulator or directly to the battery" ??

Based on a statement above that "It will use something like 64 Amphours per day" you need to replace that same amount daily, via a decent regulator placed adjacent to the battery.

A quality panel rated about 140 Watts should keep your battery sufficiently charged using the above analogy.

Maîneÿ . . .
AnswerID: 412975

Follow Up By: oldtrack123 - Thursday, Apr 15, 2010 at 10:08

Thursday, Apr 15, 2010 at 10:08
Hi
If fridge uses 64amphrs per 24 hr day at least 30depending on sunlight intensity
Obviously ,no way will you keep your battery fully charged.
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FollowupID: 683023

Follow Up By: oldtrack123 - Thursday, Apr 15, 2010 at 10:28

Thursday, Apr 15, 2010 at 10:28
Hi
As I cannot edit ignore above post , something went wrong & parts are missingi
fridge draws 64 amp hrs MIN during 24hrs ,running as a freezer I would expect more like70<80 amphrs
But even taking the 64amp hrs as correct:
A 140 watt panel will put out a max of about 50amphrs per day in very good conditions
The fridge will draw probably around 20<30% of that 64amphrs from the battery during the night unless overnight temps are very cold
that 20<30% has to be replaced in the battery with normal loss of 25%< 40%
Your battery will gradualy be losing charge
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FollowupID: 683025

Follow Up By: Maîneÿ . . .- Thursday, Apr 15, 2010 at 20:09

Thursday, Apr 15, 2010 at 20:09
oldtrack,
I’m sure you’re aware it was Boobook, who stated 64 Amps and not me
You should tell him he’s wrong, but I've broad shoulders and will accept the blame.
But back to the matter of the thread concerned.

Put the calculator away and let’s use some real life conditions.

Fact; when the traveler arrives at the camping spot, he will have a charged battery
charged either by alternator or solar panel

BP 140 Watt panel is rated @ 8 Amps

The battery will continue to be charged by the solar panel only when it’s lost amperage due to running the fridge, till low light conditions prevail.
The battery will then run the fridge unaided all night.

The fridge will draw ~8 Amps, but as it runs on a ~33% duty cycle (2.7ah) during the night and all non solar assisted hours (16 hrs per day) ~43ah maximum, the solar panel will recharge the battery at max charge in early morning due to low voltage and will also run the fridge simultaneously.

The battery will be fully charged during the day and will again run the fridge again next evening unassisted, this will continue indefinitely while the solar panel is producing its rated power.

Maîneÿ . . .
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FollowupID: 683088

Follow Up By: oldtrack123 - Thursday, Apr 15, 2010 at 21:14

Thursday, Apr 15, 2010 at 21:14
Hi Mainey
I am not sure how you got the figures you have.Or the 8amps for the fridge

BUT:

Aussie wishs to run the fridge as a freezer so 33% duty cycle is unrealistic.
The figure of 64 amphrs per day as posted by 2 others is much more realistic as a mininum based on fridge drawing 4.5amps when actually running & depending on ambient temp could be much higher
The 140 watt solar panel will contibute about 56< 60amp hrs per day especially if mounted flat.
Of the 64 amphrs drawn by fridge about 30<40amphrs will be pulled from the battery,based on 14hrs with little solar input.
That 30amphrs has to be replaced but since charging is not 100% efficient it wil need about 30% extra[about another 9amp hrs]
[a]Total to recharge battery is 39 amphrs
[b]Fridge during day will more likely be running in excess of 60% of the time drawing 4.5amps x 10hrs x 60%= 27amp hrs

[a] +[b]= 39+27= 69 amphrs req for 24hrs
Battery is loosing charge @ rate of 9< 13amphrs per 24 hrs just supplying fridge /freezer
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FollowupID: 683097

Follow Up By: Maîneÿ . . .- Thursday, Apr 15, 2010 at 21:38

Thursday, Apr 15, 2010 at 21:38
It's a known fact the average power consumption for the 80Lt Waeco is 2.9ah @ -15°c freezer, in 32°C ambient temperature.

However because the fridge operates 24/7 the ambient temp is reduced at night as is also the ah number, but by just O.2ah.

As I said using a calculator to do the maths is not even realistic.

I don't wish to be accused of putting this thread into the same situation of the 'locked' solar thread.

Maîneÿ . . .
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FollowupID: 683099

Follow Up By: oldtrack123 - Thursday, Apr 15, 2010 at 22:08

Thursday, Apr 15, 2010 at 22:08
Hi Mainey
Once again you show you have little understanding of FACTS

From Waeco site
"Power Av. Power Consumption: 2.9 amps/hr (@ 12V, 5°C fridge, -15°C (approx.) freezer, 32°C ambient temperature)"


Clearly says AVERAGE consumption 2.9amphrs X by 24hrs =69amphrs
Very close to the figures others have quoted
Again it seems every one else but you are wrong !!!
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FollowupID: 683103

Follow Up By: Alloy c/t - Thursday, Apr 15, 2010 at 22:19

Thursday, Apr 15, 2010 at 22:19
Mainey , twas I who stated 64 amp hrs used by the 80 per 24hrs ,used as a fridge freezer , 6+ yrs use thru a steca 2020 ,, REAL life usage =64ah per24hr summer and winter ,no ifs ,no buts , only real measurable varience is if divider is removed to create all fridge or all freezer , use as ALL freezer will use a minimum of 110/120 amp hrs per 24 and as ALL fridge 80/90 amp hrs per 24 to maintain a + 2-4c temp,
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FollowupID: 683104

Follow Up By: Maîneÿ . . .- Friday, Apr 16, 2010 at 22:30

Friday, Apr 16, 2010 at 22:30
oldtrack,
you just need to read and actually understand what is written
obviously you don't understand it too well
Because I've posted in Followup ID: 683099

"It's a known fact the average power consumption for the 80Lt Waeco is 2.9ah @ -15°c freezer, in 32°C ambient temperature"

I also posted: "The fridge will draw ~8 Amps, but as it runs on a ~33% duty cycle (2.7ah) during the night and all non solar assisted hours (16 hrs per day) ~43ah maximum"

The 43ah is stated as *ONLY* during the NON sun hours, it is NOT including the 8 hours of the day when the sun shines.

That will bring the number up to ~64ah

Exactly the same number as everyone else is using

maybe you should check your English dictionary or check your calculator :-)

Maîneÿ . . .
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FollowupID: 683297

Follow Up By: oldtrack123 - Friday, Apr 16, 2010 at 22:45

Friday, Apr 16, 2010 at 22:45
HI Mainey
"The battery will be fully charged during the day and will again run the fridge again next evening unassisted, this will continue indefinitely while the solar panel is producing its rated power. "

So now perhaps you can explain how a 140w solar panel putting out on average 50< 60 amphrs in good weather can replace 64amphrs used by the fridge plus the extra LOSSES from recharging the 43 amp hrs drawn from the battery overnightl INDEFINATELY !
& still remembering Aussie wants to use it as a full freezer so amp hr draw is going to much higher than 64
Probably up to 90 +amp hrs

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FollowupID: 683303

Follow Up By: Maîneÿ . . .- Friday, Apr 16, 2010 at 22:57

Friday, Apr 16, 2010 at 22:57
oldtrack,
you believe using ohm's law you can use the voltage of a battery that's voltage that has been regulated down to just 14.3v by a regulator, to be able to nominate the Wattage of a solar panel.

That is fact, I did not make it up, you posted it, so I don't expect you will understand anything relative to 12v electronics at all, so I'm not going to embarris you any further

Maîneÿ . . .
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FollowupID: 683306

Follow Up By: Lex M (Brisbane) - Saturday, Apr 17, 2010 at 09:35

Saturday, Apr 17, 2010 at 09:35
Apparently Ohm's law doesn't work where Mainey resides.

cheers
Lex M
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FollowupID: 683352

Follow Up By: oldtrack123 - Saturday, Apr 17, 2010 at 10:08

Saturday, Apr 17, 2010 at 10:08
Hi Mainey

Once again you show your complete lack of knowledge of ANYTHING electrical
I take it from your last reply that you simply cannot answer the question :

"How can a panel which is only putting out 50< 60amphrs per day keep a battery fully charged INDEFINATELY with a fridge drawing in excess of 64 amphrs per day plus the losses when replacing the battery charge used overnight [ recharging] "
I suppose the efficiency LOSS when recharging the battery to replace the overnight discharge was beyound your knowledge

I do happen to be a qualified electrician
Many many years sevicing electronic equipment of all types ,

Mainey
All that your posts do is destroy threads ,with your lack of knowledge on anything electrical only confusing others
It still seems that all those with real knowledge are wrong & you are never wrong
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FollowupID: 683355

Follow Up By: oldtrack123 - Saturday, Apr 17, 2010 at 11:06

Saturday, Apr 17, 2010 at 11:06
HI Lex
"Lex M (Brisbane) posted:
Apparently Ohm's law doesn't work where Mainey resides. "

Or watts, power,or any of those things so important if one is involved in electricity.
But
NAAH we do not know what we are talking about, only the ALL KNOWING ONE WHO I believe can not be in anyway qualified.
The old problem "A little knowledge can be dangerous"
Especially when given as advise to the unknowing.

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FollowupID: 683358

Follow Up By: Member - Boobook - Saturday, Apr 17, 2010 at 11:42

Saturday, Apr 17, 2010 at 11:42
Maîneÿ . . . posted:
"oldtrack,
I’m sure you’re aware it was Boobook, who stated 64 Amps and not me
You should tell him he’s wrong, but I've broad shoulders and will accept the blame. "

Mainey, for the 1000th time you misquote me.

Show me where on earth I said that.
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FollowupID: 683361

Follow Up By: Lex M (Brisbane) - Saturday, Apr 17, 2010 at 18:25

Saturday, Apr 17, 2010 at 18:25
Hi Oldtrack123

"Or watts, power,or any of those things so important if one is involved in electricity. "

We shouldn't give up. He seems to have finally grasped the concept of Amphours.
Only about 10 more concepts to go......
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FollowupID: 683400

Follow Up By: Maîneÿ . . .- Sunday, Apr 18, 2010 at 19:04

Sunday, Apr 18, 2010 at 19:04
Lex,
Just one easy question for you,
with only a 'yes' or 'no' answer please.

Can ohm's law be used to assertain the Watts of a solar panel, given ONLY the following information.

(1) The out-put is 12 Amps
(2) The Voltage of a battery that is also running a fridge and has been regulated down by the solar regulator to just 14.3v

Just a one word answer please 'yes' or 'no'

Will I get a 'yes' or 'no' one word reply - don't think so

Maîneÿ . . .
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FollowupID: 683545

Follow Up By: oldtrack123 - Sunday, Apr 18, 2010 at 19:47

Sunday, Apr 18, 2010 at 19:47
Hi Lex

Now exactly what watts is he asking you about, the watts the panel is putting out or its rated watts or what watts??????
Or does he know the differance????
Do not forget anything other than a yes/no answer is beyond his comprehension
Also if the answer is not the one he wants you must produce pictures to prove your point
Even if you use his own pictures he will not accept the answer
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FollowupID: 683565

Follow Up By: oldtrack123 - Sunday, Apr 18, 2010 at 20:27

Sunday, Apr 18, 2010 at 20:27
Hi Mainey
Now some questions for you which of the following formulae are correct.
TO ALL others please for MAINEy to answer & show his knowledge.
I bet Google will be flat out

#1 for you to give the formula for OHMS lawl

#2 Power P[watts] = I amps x R [ohms

#3 Power P[watts ]= E x I

#4 Power [P] = Ix I x R

#5 E [v] =I/R

#6 I [amps] =P [watts] /R

#7 I = P/ E

#8 R = P/ E xI

#9 R = E/I

#10 R = I/E
Just the # AND please just a YES or NO answer
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FollowupID: 683571

Follow Up By: Lex M (Brisbane) - Sunday, Apr 18, 2010 at 21:26

Sunday, Apr 18, 2010 at 21:26
Mainey said:-
"Lex,
Just one easy question for you,
with only a 'yes' or 'no' answer please.

Can ohm's law be used to assertain the Watts of a solar panel, given ONLY the following information.

(1) The out-put is 12 Amps
(2) The Voltage of a battery that is also running a fridge and has been regulated down by the solar regulator to just 14.3v "

Lets start with some corrections.

From Mainey's profile :-
#Ohm's Law
The math needed for electrical calculations *with-in same* appliance
For DC circuits: Watts = Volts x Amps.

This is in fact Joule's law which states:-
In direct current resistive circuits, electrical power is calculated as
P=VI
where P is the electric power, V the potential difference, and I the electric current.


The real Ohm's law:-
Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and inversely proportional to the resistance between them.
V = IR (or equivalent expressions)

So using the real Ohm's law as opposed to Mainey's incorrect Ohm's law the answer must be

"No".

It is not possible to calculate a wattage figure using Ohm's law.



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FollowupID: 683583

Follow Up By: Member - Boobook - Monday, Apr 19, 2010 at 06:16

Monday, Apr 19, 2010 at 06:16
Mainey, you ignored my question about you misquoting and getting things wrong again.
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FollowupID: 683598

Follow Up By: Maîneÿ . . .- Monday, Apr 19, 2010 at 07:34

Monday, Apr 19, 2010 at 07:34
Lex has now clarified misinformation posted in locked thread #77244
"SOLAR panel efficiency - debunking myths?"

With Lex having the final say, stating ohm's law can't be applied to a battery that's regulated, to ascertain the Wattage of a solar panel.

It just shows how very wrong ‘most’ of the posts are in that locked solar information thread, as many uninformed posters stated vehemently battery voltage can be used to ascertain the Wattage in a solar panel, even putting up the equation as proof their thoughts were correct.

Makes me wonder why lex never told any of them they were in fact wrong ?
(there are various ways to skin a cat)

aussichef,
I'm sorry about the hijacking, information eventually obtained is relevant to solar knowledge

Maîneÿ . . .
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FollowupID: 683602

Follow Up By: Member - Boobook - Monday, Apr 19, 2010 at 07:40

Monday, Apr 19, 2010 at 07:40
Mainey's Law.

1+1 = 3
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FollowupID: 683603

Follow Up By: Member - Boobook - Monday, Apr 19, 2010 at 07:59

Monday, Apr 19, 2010 at 07:59
Mainey, once again I request that you address where you misquoted me once again. Obviously you have chosen to ignore my previous requests on this follow up given that you continue to post.

I guess take it that you acknowledge that you misquoted me in your refusal to address your mistake.
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FollowupID: 683606

Follow Up By: Maîneÿ . . .- Monday, Apr 19, 2010 at 08:15

Monday, Apr 19, 2010 at 08:15
Boobook, Yes I've chose to ignore you

Maîneÿ . . .
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FollowupID: 683609

Follow Up By: Member - Boobook - Monday, Apr 19, 2010 at 11:10

Monday, Apr 19, 2010 at 11:10
Oh..... alll right Mainey, then have it your way. Gawd save me.

However in future may I ask that you do not add or delete words to my posts and then quote the result as from me.

This is not the first time you have misquoted me and changed the context of what I said in order to suit your argument. It really is annoying and misleading.

All I ask is that you quote ALL of what I say in a post, or NONE of what I say. With no edits from yourself attributed to me. Fair?
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FollowupID: 683624

Follow Up By: Lex M (Brisbane) - Monday, Apr 19, 2010 at 11:44

Monday, Apr 19, 2010 at 11:44
Lex has now clarified misinformation posted in locked thread #77244
"SOLAR panel efficiency - debunking myths?"

With Lex having the final say, stating ohm's law can't be applied to a battery that's regulated, to ascertain the Wattage of a solar panel.

***


Don't you just love the way Mainey selects the bit he likes and ignores the rest.

You're correct Mainey, I said it can't calculated with WITH OHM's LAW.
I did not say it can't be calculated.

And I'll bet he makes no attempt to correct the error in his profile that I highlighted above.

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FollowupID: 683625

Follow Up By: Maîneÿ . . .- Monday, Apr 19, 2010 at 17:49

Monday, Apr 19, 2010 at 17:49
Lex, I do only use information relevant to the information or the question, I don't go off on tangents and bring in other information not relevant at all to the question or the reply.

I asked 0NE question to be answered with only a 'yes' or 'no' reply

"Can ohm's law be used to assertain the Watts of a solar panel, given ONLY the following information
*The out-put is 12 Amps
*The Voltage of a battery that's also running a fridge and has been regulated down by the solar regulator to just 14.3v"

Your answer in the single word I've specifically asked for is "NO" it can't!

So I "select" the answer you gave and not the plethera of information that you choose to put there that was not asked for, in fact was specifically asked NOT to be put there.
I don't see a problem, I asked for a one (1) word reply, you choose not to

Maîneÿ . . .
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FollowupID: 683658

Follow Up By: Lex M (Brisbane) - Monday, Apr 19, 2010 at 19:28

Monday, Apr 19, 2010 at 19:28
Mainey
You "select" the answer for a bogus question because it suits your purpose.

Had you asked the question

"Can you ascertain the Watts of a solar panel, given ONLY the following information.

(1) The out-put is 12 Amps
(2) The Voltage of a battery that is also running a fridge and has been regulated down by the solar regulator to just 14.3v " The answer would be "yes"

Since you entered your erroneous interpretation that Ohm's law was somehow relevant to the question, there is no option but to answer "no"

If you insist on specifying the law to be used, the question should have been
"Can JOULES's law be used to ascertain the Watts of a solar panel, given ONLY the following information. etc..

You have once again displayed total lack of electrical knowledge and the inability to accept science and fact.

***

This forum should have a warning notice to this effect.

"Any discussion on this forum regarding Solar Power containing a post by Mainey should be totally ignored."

Hmmm. That will probably be moderated. Oh well.........



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FollowupID: 683671

Follow Up By: Lex M (Brisbane) - Monday, Apr 19, 2010 at 19:53

Monday, Apr 19, 2010 at 19:53
Hey look. I lost that bet I made in followup 26 above.

The offending statement :-

#Ohm's Law
The math needed for electrical calculations *with-in same* appliance
For DC circuits: Watts = Volts x Amps.

has disappeared from Mainey's profile.

Well done Mainey, you really did read more than the yes/no answer. There's a chance for you yet........
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FollowupID: 683677

Follow Up By: oldtrack123 - Monday, Apr 19, 2010 at 22:16

Monday, Apr 19, 2010 at 22:16
Hi Lex
I think he removed it because he thinks that: watts =volts x amps is incorrect

But since it is correct, it destoys his thread "Myth of solar panel efficiency"
Since watts does equal volts by amps
He believes his 204watt solar panels are 100% efficient
But ,if the fomula is correct, his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient
I saw straight away that he was again trying to prove his point on the thread that was locked


Mainey
Still waiting for YOUR simple "yes' or "NO" answers to those formulae.

Lex
I wonder what he would come up with re:
An appliance draws 10amps on 240v
What will it draw on 190v ?

Come on Mainy show us what you are made of ,do not be a chicken
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FollowupID: 683698

Follow Up By: Lex M (Brisbane) - Monday, Apr 19, 2010 at 23:23

Monday, Apr 19, 2010 at 23:23
Careful oldtrack123. Don't get too cocky about this.

"An appliance draws 10amps on 240v
What will it draw on 190v ? "

Let's be fair about this.
There's not enough information to answer that.

Is that 240v and 190v AC or DC?
What type of appliance?
Is it a resistive device with a positive or negative temperature coefficient?
EG toaster, heater, incandescent light.
Is it an inductive device?
EG fan, electric drill.
Is it an electronic device with analogue or switch mode power supply?
Big difference between those two.
Is it a device with a regulated output like a battery charger or similar?
etc.
The question is unanswerable, and I rate it as bad as some of Mainey's comments above.

And as for your list of questions above.
I have a problem answering #1
Is Ohm's law "yes" or "no"?

You've done exactly the same thing as Mainey. Asked a question which can't be answered within the confines of the available information and/or rules.





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FollowupID: 683710

Follow Up By: oldtrack123 - Tuesday, Apr 20, 2010 at 10:07

Tuesday, Apr 20, 2010 at 10:07
Hi Lex
Agree , all your comments are valid & like you ,those who know what is involved would want similar clarifcation before giving a definate answer.
Instead of devise I probably should have said "resistor"
I wanted to keep it simple so as to not confuse Mainey
But in responce to your questions I'll add :

the load is purely resistive
,
the resistor is held at a constant temp . or I could say that the resistor is of such current carrying capacity as to not be significantly affected by the relatively small change in current that would occur with the small voltage change indicated. The reason I did not make a major change in voltage

supply is DC


The reason for asking this is that I have found a lot of threads on many forums where many ,including some who should know better do not use the right formula
If you are interested I could trace the links to those threads ,you may be suprised just how misunderstood this simple basic calculation is.
I'll say no more on that @ this point as I think the explananation should be left untill we see if Mainey can answer the simple case as clarified above.
Re list of Formulae ,#1 is perhaps poorly worded but asks for Mainey to give his formula for OHM's law
The remainder ask for yes or no answers
Peter
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FollowupID: 683728

Follow Up By: Maîneÿ . . .- Tuesday, Apr 20, 2010 at 23:44

Tuesday, Apr 20, 2010 at 23:44
oldtrack,
You posted above: " his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient "

oldtrack,
how many times do you have to be told the 14.3v is *NOT* relevant at all to ascertaining the Wattage of my solar system ?

I still believe you know nothing at all about solar power, your posts above show that.

Please ask Lex to explain to you why 14.3v is *NOT* relevant 0R correct either

Lex has even given you the answer, you still don't accept it, maybe because you can't understand it, obviously you need some serious education and I'm sure Lex can set you straight.

(I'm truly sorry about the hijacking of this thread - my *last* post here)

Lex, can you please assist oldtrack to understand the problem he has with the method he's using to ascertain my solar panel Wattage ?

Maybe even better to start a new thread and attempt to teach him, it may be a slow process, but I know you are capable and he's needing your expert assistance
thanking you in advance :-)

Maîneÿ . . .
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FollowupID: 683852

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 09:42

Wednesday, Apr 21, 2010 at 09:42
Hi Mainey

Now I realy understand your problem
You are blind to anything that does not suit your theorys
Read again what Lex said

Lex M (Brisbane) posted:
Mainey
You "select" the answer for a bogus question because it suits your purpose.

Had you asked the question

"Can you ascertain the Watts of a solar panel, given ONLY the following information.

(1) The out-put is 12 Amps
(2) The Voltage of a battery that is also running a fridge and has been regulated down by the solar regulator to just 14.3v " The answer would be "YES "

MAINEY ,DID you see that word "YES" & that is exactly what I have done to show the ouput from your panels is 84% of rated output ,NOT 100% as you continue to claim

I am sure Lex will TRY to educate YOU
But I am afraid & sorry for you that it does seem a hopeless task.

I think ALL should take note of Lex's warning below:

This forum should have a warning notice to this effect.
"Any discussion on this forum regarding Solar Power containing a post by Mainey should be totally ignored."





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FollowupID: 683887

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 10:33

Wednesday, Apr 21, 2010 at 10:33
oldtrack,
You posted above: " his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient "

Please explain how this works - I bet you can't !


To ascertain the Wattage of any solar panel you have to use the ‘Amps’ and the ‘Voltage’ produced AT THE SOLAR PANEL.

You can't use the “charging voltage” of a battery that’s been regulated down to just 14.3v to get the solar panel wattage, your maths have proved it’s impossible, but you can't see it as you keep making the same dumb mistake time after time.

If you use the voltage actually produced by the solar panel * BEFORE * its regulated down to 14.3v it will register @ ~17v and definitely not 14.3v.

Then do your maths again and see how it WILL produce a 203 Watt answer.
( 16.9 volts x 12 amps = 203 watts )

The 14.3v you keep referring to is ONLY the *charging voltage* of the battery

My solar system is charging the battery @ 14.3v as shown on the Voltage gauge attached to the battery, (which is also running a fridge) and NOT on the regulator or the solar system, that's totally different to the voltage produced by the solar system which is ~17v before it is regulated down to 14.3 @ the battery, as I’ve clearly explained to you so many times previously, so it's not new information, you obviously just don’t understand it at all.

I don't know why you can't see the difference, the only thing I can think I unfortunately can't print here, maybe Lex will show you the error of your thinking, and then maybe he won't, not because he can't, but because he just won't want to show you how you have, and continue making the same stupid mistake of using the charging battery voltage in an attempt to ascertain the solar panel Wattage, it just can't be done as you have attempted to do.

You may as well use the charging voltage of the cranking battery or your neighbors cranking battery, as either battery voltage will give the exact same wattage as you get - which as you can clearly see is totally incorrect.

Maîneÿ . . .
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FollowupID: 683896

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 10:58

Wednesday, Apr 21, 2010 at 10:58
Hi Mainey
I am actuall;y starting to feel sorry for you.
You are obviously blind to anything that doed not suit your theory
AGAIN READ Lex's post:


Can you ascertain the Watts of a solar panel, given ONLY the following information.

(1) The out-put is 12 Amps
(2) The Voltage of a battery that is also running a fridge and has been regulated down by the solar regulator to just 14.3v " The answer would be "YES "
CAN YOU SEE IT the answer would be "YES" as per so many of my posts TRYING to explain to you Your panels are only 84% efficient
Or are you saying Lex is now wrong too???

A litle suggestion I made to you on the other thread,GO & check what voltage you get on the panel side of your reg with your 12amp output.
One other little question do your batterys ever reach full charge, if so what amps do your meters show then???
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FollowupID: 683899

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 11:20

Wednesday, Apr 21, 2010 at 11:20
oldtrack,
You posted above: " his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient "

Oldtrack, you read YOUR post as shown above.
that is what we are talking about, ' YOUR ' total lack of solar knowledge

As I've asked, please explain how this works - I bet you can't !



You then ask: "One other little question do your batterys ever reach full charge, if so what amps do your meters show then"

I think you meant 'batteries' ??
Do you want to tell me something is wrong with the photo?

Your answer:
Image Could Not Be FoundMaîneÿ . . .
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FollowupID: 683901

Follow Up By: Member - Boobook - Wednesday, Apr 21, 2010 at 11:24

Wednesday, Apr 21, 2010 at 11:24
Unbelievable.

Every time there is a Solar / 12v question, it degenerates to an exercise in correcting / educating one individual from the time they post wrong information.

By misquoting other posters who often correct this advice, that person forces them to respond. However it goes into a viscous circle and the whole thread becomes poisoned because of manipulated quotes and extremely bad advice that gets worse as the person 'digs in'.

Unfortunately almost every 12v/ solar thread becomes a lengthy but useless debate.

I really pity anyone that asks a simple 12v question once photos of 12A regulators appear.

Will this go on for every 12v question on this otherwise fantastic forum?
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FollowupID: 683902

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 11:33

Wednesday, Apr 21, 2010 at 11:33
Boobook,
the question was asked of me, "One other little question do your batterys ever reach full charge, if so what amps do your meters show then"

I posted the photo above showing the precise answer, so there can be no confusion and no confrontation either, as it’s self explanatory to anyone who understands what the numbers actually represent.

Maîneÿ . . .
0
FollowupID: 683906

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 11:56

Wednesday, Apr 21, 2010 at 11:56
Hi Boobook
I agree ,it is a shame that so many threads go this way on many forums
Usually due to those who post incorrect info which they cannot justify/ explain their reasoning's when asked
You will note Mainey has not answered any asked of him.
But the question is ,what should be done. should incorrect info go unchallenged & possibly be perpetuated by others who believe it or should every attempt be made to insure that such info is corrected
The amount of incorrect & sometimes potentially dangerous info on electrical subjects I have seen on forums is unbelievable
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FollowupID: 683909

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 12:16

Wednesday, Apr 21, 2010 at 12:16
Hi Mainey
Thanks for the photo .It does show what i would expect.

Now why don't you answer those other questions??

Re trying to explain your panel efficiency I have done that in every way possible on this & that other thread
You have refused to accept that
So I will leave it to Lex to show & explain
You are obviously saying Lex does does not know what he is talking about too
when he says:

"Can you ascertain the Watts of a solar panel, given ONLY the following information.

(1) The out-put is 12 Amps
(2) The Voltage of a battery that is also running a fridge and has been regulated down by the solar regulator to just 14.3v " The answer would be "YES "
NOTE HIS answer : YES YES YES YES

You constantly refer to the 17v @ the panel .
Please show all of us a picture of that while the panel is putting out the 12amps
Remember I have asked you numerous time to check that voltage ,for some reason of your own you have not done that.
However I will tell you what it WILL be
It will be .25v<.75 volts higher than your battery voltage @ that time, due to a small loss in the reg & possibly wiring
This will be true even when you are drawing less amps!!!
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FollowupID: 683912

Follow Up By: Lex M (Brisbane) - Wednesday, Apr 21, 2010 at 12:40

Wednesday, Apr 21, 2010 at 12:40
"If you use the voltage actually produced by the solar panel * BEFORE * its regulated down to 14.3v it will register @ ~17v and definitely not 14.3v."

Yet again we see a totally erroneous statement.

The Steca solar regulator is, I believe, a PWM shunt regulator. This being the case the solar panel voltage will never be more than a fraction of a volt higher than the battery voltage. Mainey, feel free to prove me wrong by measuring this voltage and showing us.

When in bulk charge mode, the regulator effectively acts as a short circuit between the solar panel and battery.
The voltage before and after the controller will be identical (disregarding switching losses).

When in an output voltage control mode as in equalisation mode, the output voltage will be controlled by SHORT CIRCUITING the solar panel.

I assume this is how the regulator measures the solar panel current,
Mainey's notorious 12Amps. Really has no relevance to the charging current.

Measuring the solar panel voltage at this time will show a voltage less than the battery voltage due to the PWM shunting.

The Steca has a screen display which shows the battery charging current, according to the user manual. ONCE AGAIN I ask Mainey to give us a picture which shows THAT display, as that is the relevant information for calculating efficiency.

This request has been repeatedly ignored.

If we had that figure and the battery voltage, we could calculate the real
power output of his solar system using Joule's law. P=VI.

With regard to the manufacturer's specifications, unless you can measure the solar radiation when making the measurements, you can neither prove nor disprove their figures.

I now withdraw from this thread.

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FollowupID: 683915

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 13:37

Wednesday, Apr 21, 2010 at 13:37
Now guys,
You have missed the point, maybe because you know to admit the equation I've used, ~17v x 12a = 203 watts shows my system is operating at the performance stated by the manufacturer.
Remember, they are also the same numbers shown on the manufactures website.
Why is it so difficult for you to believe them when I show the Amps produced by the solar panel in a photograph?


Lex, you say; "When in bulk charge mode, the regulator effectively acts as a short circuit between the solar panel and battery. The voltage before and after the controller will be identical (disregarding switching losses)"

So your now saying the battery is receiving ALL the voltage put out by the solar system when in bulk charge mode, except the miniscule "switching losses" ?
What actual voltage values (stated as Volts) are you referring to here?

The Steca website states;
Float voltage is 13.9v
Boost voltage is 14.4v
Equalization voltage is 14.7v

The voltage at my battery is 14.3v, so you say the voltage produced by the solar system is also ~14.3v allowing for any “miniscule switching losses" and is not ~17v, as is stated by the panel manufacturer ?

Maîneÿ . . .
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FollowupID: 683922

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 14:13

Wednesday, Apr 21, 2010 at 14:13
Hi Mainey

I give up ,
Yes you must be right even when you do not understand even basic
electricity
Less than a 1st year apprentice would

All those with an electrical back ground are wrong

Since you cannot understand basics ,it would be impossible to explain to you the higher points of how /why / where that 17v disappears to.
But as you have been repeatedly asked go & check the actual voltage you get from the panels
It will be marginally above the battery volts no matter what voltage they show [@12v it will show possibly 12.25 volts
Just to confuse you even further @ that 12.5v x 12amps =150watts output your panels are now only 73.5% efficient
How does that make you feel
The efficiency drops the lower the load volts!!!

Your biggest problem is that you believe that the regulator controls the output voltage of the panel. IT DOES NOT!!!

Trying to keep it simple for YOUR benefit .
It regulates the battery voltage by means of current control / switching!!
as per Lex's post
Max available amps[ Full on]when actually CHARGING or shunted to short PANELl out, when no amps going to battery
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FollowupID: 683926

Follow Up By: Lex M (Brisbane) - Wednesday, Apr 21, 2010 at 14:46

Wednesday, Apr 21, 2010 at 14:46
quote
"So your now saying the battery is receiving ALL the voltage put out by the solar system when in bulk charge mode, except the minuscule "switching losses" ?"

No I'm not saying that.

A solar panel is a current supplying device. If your battery is partly discharged and in the first stage of charging then the solar panel is (effectively) connected directly to the battery.

The voltage will depend on the state of charge of the battery, the internal resistance of the battery, and the current flowing and will increase until it reaches a level where the controller will switch charging mode to a voltage control mode (second stage of charging).

This first stage charging is the only time that the maximum output of the solar panel can be used. After that the controller "wastes" solar power to control the BATTERY voltage.

quote
"What actual voltage values (stated as Volts) are you referring to here?"

The battery voltage, which as I said will depend on the state of charge of the battery, the internal resistance of the battery, and the current flowing.

A solar panel does not control the voltage level. The voltage at the output of a solar panel is dependant on the light conditions and the load.





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FollowupID: 683931

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 15:41

Wednesday, Apr 21, 2010 at 15:41
You guys have a way with words :)

given that 12 Amps is produced at the solar panel how do you work out the Wattage of said solar panel ??

Remember I have *not* given you any voltage number here.

Maîneÿ . . .
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FollowupID: 683941

Follow Up By: Lex M (Brisbane) - Wednesday, Apr 21, 2010 at 15:48

Wednesday, Apr 21, 2010 at 15:48
qoute
"given that 12 Amps is produced at the solar panel how do you work out the Wattage of said solar panel ??

Remember I have *not* given you any voltage number here."

Impossible question.


Like saying:-
" I'm travelling at 100 k/hr how far have I travelled?
Remember I have *not* given you any time here."


0
FollowupID: 683943

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 16:10

Wednesday, Apr 21, 2010 at 16:10
Mainey
How about you do the simple thing that has BEEN CONSISTANTLY ASKED OF YOU,on this & the other thread go & measure the actual voltage @the panels while under load[ charging batteries ]
Then as an additional test put some more load on [lights ,fridge etc] & again read the voltage @ your meters & @ the panel
I have already told you what to expect ,about .25v difference, no matter what current you are showing going in
Not your 17v
So go on PROOVE me wrong ,surely you would love to do that
You could even post a photo

We are not playing with words ,you seem to be the one that is very selective in what you want to read & then post stupid follow ups
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FollowupID: 683947

Follow Up By: Alloy c/t - Wednesday, Apr 21, 2010 at 17:55

Wednesday, Apr 21, 2010 at 17:55
17vollts x 12amps = 204watts , do 240v electricians or for that matter auto electricians KNOW about solar enough that they can argue the priciples involved in a solar panel output , dont think so , just have to look at all the ineffcient wireing done in fitting 2nd/3rd battery systems to vehicles and c/ts and caravans.
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FollowupID: 683965

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 18:05

Wednesday, Apr 21, 2010 at 18:05
Ok,
asked another way
I buy a solar system
the system manufacturer states: 203 Watts, 17v, and produces 12 Amps.

oldtrack has claimed: "if the fomula is correct, his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient "

Now where does the 84% efficiency come from, when it can clearly be shown to be producing the full 12 Amps, as is claimed by the manufacturer ?

Maîneÿ . . .
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FollowupID: 683967

Follow Up By: Lex M (Brisbane) - Wednesday, Apr 21, 2010 at 18:17

Wednesday, Apr 21, 2010 at 18:17
Alloy c/t said
"17vollts x 12amps = 204watts , do 240v electricians or for that matter auto electricians KNOW about solar enough that they can argue the priciples involved in a solar panel output"

Don't know about that but I'm neither of those so that doesn't apply to me.


0
FollowupID: 683969

Follow Up By: Lex M (Brisbane) - Wednesday, Apr 21, 2010 at 18:22

Wednesday, Apr 21, 2010 at 18:22
Mainey said
"the system manufacturer states: 203 Watts, 17v, and produces 12 Amps.

oldtrack has claimed: "if the formula is correct, his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient "

Now where does the 84% efficiency come from, when it can clearly be shown to be producing the full 12 Amps, as is claimed by the manufacturer ? "


rated at 204 watts, battery is receiving 171.6 watts.

Using my solar powered calculator I divide 171.6 by 204 and I get......

0.84117647058823529411764705882353 which is approximately 84%.

Really Mainey, you can't be serious.




0
FollowupID: 683971

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 18:31

Wednesday, Apr 21, 2010 at 18:31
Lex,

obviously you believe the usual calculation;

17v x 12a = 204w is not correct then ?

Maîneÿ . . .
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FollowupID: 683972

Follow Up By: Lex M (Brisbane) - Wednesday, Apr 21, 2010 at 18:44

Wednesday, Apr 21, 2010 at 18:44
17v x 12a = 204w is not correct then ?

Perfectly correct, but totally irrelevant when charging a battery unless you're using a MPPT regulator when you may get close.
You're not.


As has been said, show us a picture of your 204 W solar panel charging a battery with a voltage of 17V and a current of 12A.

I say you can't.

Prove me wrong.

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FollowupID: 683974

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 19:01

Wednesday, Apr 21, 2010 at 19:01
Alloy c/t posted:
17vollts x 12amps = 204watts , do 240v electricians or for that matter auto electricians KNOW about solar enough that they can argue the priciples involved in a solar panel output , dont think so , just have to look at all the ineffcient wireing done in fitting 2nd/3rd battery systems to vehicles and c/ts and caravans."
Hi
Yes you are correct many auto[most] & 240v electrician do not know much about solar or even van wiring requirements.
However they do have some basic knowledge which may allow them to comprehend the info given on threads likes this one & to "sort the wheat from the chaff"
Unfortunately many posters are just blind believers in their particular ideas with no TECNICAL knowledge what so ever to back them up

Those with no electrical background certainly have little chance of truly understanding !!
This is readily seen on many electrical threads including this one!!
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FollowupID: 683975

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 19:12

Wednesday, Apr 21, 2010 at 19:12
Lex,
How absolutely funny, you can make me laugh, you tell me my calculation is "totally irrelevant" however you never mentioned Oldtrack's calculation is "totally irrelevant" or any way even incorrect either, obviously you must then believe his calculation is correct...?

oldtrack has claimed: "if the fomula is correct, his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient "

So yes, obviously you believe oldtrack's calculation to be correct when it's blatantly obvious in the photo the 14.3v is only the battery *charging voltage*, nothing to do at all with the solar panel voltage in any way shape or form at all, and not even relevant to his mathematical calculation as shown.


The photo I've used shows the 12 Amps is produced at the solar panel
the battery charging voltage is 14.3v, which is about the correct 'boost voltage' of the Steca solar regulator (14.4v)

The 17v is produced at the solar panel, N0T the battery or regulator, but I thought you would have know that.
You ask for something that is only as relevant as the 203 Watts, not too important at all when the Amps are so clearly shown as available to charge the battery when required.

Maîneÿ . . .
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FollowupID: 683981

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 19:15

Wednesday, Apr 21, 2010 at 19:15
Hi to ALL Forum members
I think Lex's line
" This forum should have a warning notice to this effect.
"Any discussion on this forum regarding Solar Power containing a post by Mainey should be totally ignored"

I think it should be changed to\ "Any post, & in particular this ,by Mainey
* To check-out how SÔLAR PÔWER & :3 Vølt Batteries will work * should be totalloy ignored. HE HAS NO IDEA on anything electrical"



0
FollowupID: 683983

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 19:32

Wednesday, Apr 21, 2010 at 19:32
Hi Mainey
You know this is getting a bit boring with your constant harping back to your 12amps which on their own means nothing
Please SHOW US THAT 17V THAT YOU TALK ABOUT.

Now just to stir you up ,your battery is actually storing watt hrs of energy & it requires watthrs of energy to recharge it.
I know this will be well beyond you but it is FACT
If you had a watt meter in line you would see the watts input into the battery .
If you had a watthr meter such as your home power meter in the circuit it would indicate watthrs received from the solar panel.!!!

SIMPLY put for YOUR benefit ,energy is power = watts
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FollowupID: 683990

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 19:52

Wednesday, Apr 21, 2010 at 19:52
oldtrack,
So now you suggest all those Ampere gauges out there on battery Jump-start systems and all vehicle battery system are ALL irrelevant because they show the wrong information ha ha

Do you have an Amp gauge amongst your dash-board indicators, or a “watt meter” ??

Do you have a "Watt meter” hard wired to monitor your battery system ??

Name one 4WD that has a Watt meter instead of an Amp meter to monitor battery condition.

Now you’ve really got me laughing - at you :)

Maîneÿ . . .
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FollowupID: 683995

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 20:19

Wednesday, Apr 21, 2010 at 20:19
Well MAiney ,
I have to say you do not give up.
Your reply is exactly what I expected & again shows your complete lack of comprehension as to what constitutes electrical power
Unfortunatly with your lack of basic knowledge it would be impossible to explain to you that it is watts that actually charge your battery.& why it is not used as an indicator.

But as I & Lex have tried to point out to you, amps on their own do not represent energy & energy IS WHAT YOU GET from a battery & what you need to put back in to charge it
This is the real problem ,YOUR TOTAL LACK OF BASIC KNOWLEDGE
You have been told this many many times by many many people on many many threads.

Remember ALL
ANY info from MAINEY ,on matters electrical should be disregarded.
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FollowupID: 683998

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 20:47

Wednesday, Apr 21, 2010 at 20:47
oldtrack,
Why won't you answer the questions asked of you?
Do you have a watt meter ??

Because I'm sure other guys an gals reading this (hijacked) thread may have some interest and would run out and get a "Watt meter" because it obviously works better than an Amp meter *according to you* (not me)

I've never ever seen a watt meter installed in any 12v system or vehicle and you obviously have never either or you would have nominated where they are available, to that point I googled 12v watt meter and guess what
"Search Results:
No results found for "12v watt meter"
Ummm not too readily available I think

Maîneÿ . . .
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FollowupID: 684004

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 21:07

Wednesday, Apr 21, 2010 at 21:07
Hi
Yes Mainey I knew it would be to hard for you ,with no knowledge, to understand my point
Note ,I did not say 12v watt meters or watthr meters should be used I said "if one was connected etc"

I do not know how I or anyone else could explain it to you since you believe AMPS is all you need to charge a battery

Re answering questions when are you going to answer those put to you !!

Especially the one about voltage @ the panels.
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FollowupID: 684007

Follow Up By: Member - Boobook - Wednesday, Apr 21, 2010 at 21:16

Wednesday, Apr 21, 2010 at 21:16
Oh..............my...............gawd.

Lucky couldn't find a Watt meter. It would show that some people aren't very bright!


0
FollowupID: 684012

Follow Up By: Maîneÿ . . .- Wednesday, Apr 21, 2010 at 21:24

Wednesday, Apr 21, 2010 at 21:24
oldtrack,
You say: "If you had a watt meter in line you would see the watts input into the battery. If you had a watthr meter such as your home power meter in the circuit it would indicate watthrs received from the solar panel."

Please show me ANY website selling these watt meters ?

Because Amps charge the battery, that is why you have an Amp gauge in-line to ascertain the charge going into the battery and the Voltage gauge to ascertain the charge within the battery.

The solar panel manufacturer states the panel is 203 Watts and the panel Voltage is 17v.
That is all you need to know

Maîneÿ . . .
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FollowupID: 684016

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 21:47

Wednesday, Apr 21, 2010 at 21:47
Hi
Member - Boobook posted:
Oh..............my...............gawd.

Lucky couldn't find a Watt meter. It would show that some people aren't very bright! ""


And so say all of us .
The man? cannot understand anything, will not answer simple questions ,will not accept anything that contradicts his weird ideas , even when put into simple language, it is beyond his comprehension
Every one ,now even Lex is wrong
But not Mainey HE IS THE only one who knows. [NOTHING!!]

AGAIN TO ALL
BELIEVE ANYTHING ELECTRICAL THAT MAINEY POSTS @ YOUR OWN RISK!!!

Perhaps HE is just trolling, as I cannot believe anyone could be so consistently one eyed.
His style is somewhat similar to one "Ghosta" who has been booted off several forums



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FollowupID: 684024

Follow Up By: Member - Boobook - Thursday, Apr 22, 2010 at 06:45

Thursday, Apr 22, 2010 at 06:45
I should resist, but I can't.

It's Watts that do the work, regardless of amps or volts. You need to power a 20 watt light, a 200 watt drill, etc. Measuring only the current tells you nothing about what you can do with the device.

Watt meters should really be used to measure the energy and power in devices. They generally aren't because they are harder ( more expensive) to build, install and many people wouldn't understand the reading anyway :-).

An Amp meter will give you an approximate idea of the work being done but only shows half the information. You assume the voltage is constant ( 12V etc) and therefore you are taking a best guess at the power. For most practical purposes this gives you a good idea of what is going on. To do it more accurately you should have 2 meters. A Volt meter and an Amp meter ( I recall seeing lots of photos like that somewhere ) is usually used - if understood and connected correctly, to determine power

Any good, high end solar charger will show Watts, and Watt hours.

Here is an example
Outback charger specs showing wattmeter

There is your watt meter, Mainey, and a Watt hour meter thrown in for good measure.

Solar panels are measured in watts because that is what is constant given a particular amount of sunlight under standard conditions. So many watts of light is converted to so many watts of power ( the PANEL efficiency). The voltage and current out of the panel will change constantly, depending on many variables including load, charger type, temperature etc.

All Panels have a Maximum Power Point for any set of conditions. In other words the best combination of Amps and Volts to give the maximum power in Watts.

Amongst other things, a MPPT charger continuously searches for this maximum power point ( most watts from the panel). They have to convert the Voltage from whatever this is ( say 19V for example ) to the usable voltage at the battery ( say 13.8V). Hence their efficiency.

Less capable and cheaper chargers such as your Stecca are dumber and just try to match the battery voltage with the panel voltage, this means that panels are NOT working at their maximum power point ( ie not as efficient) and in your case it looks like about 84% ( CHARGER efficiency compared to what would be available with a better charger ( eg MPPT)

The confusion comes from the fact that Panels are rated in Watts ( their power) but by convention 12v appliances are generally rated in Amps ( currnet flow) on the assumption that the voltage will be constant, which we all know is only approximately right.





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FollowupID: 684048

Follow Up By: Maîneÿ . . .- Thursday, Apr 22, 2010 at 09:04

Thursday, Apr 22, 2010 at 09:04
Boobook,
Thank you :-)
You say, and I agree, "Solar panels are measured in watts because that is what is constant given a particular amount of sunlight under standard conditions......All Panels have a Maximum Power Point for any set of conditions.
In other words the best combination of Amps and Volts to give the maximum power in Watts."

I've stated my panel is 203 Watts, because it's written on the back of the system, I believe, as you have stated, the "combination of Amps and Volts to give the maximum power in Watts" to get this Watts number you must multiply the Amps produced X *solar panel* voltage to get the Watts of the solar panel and the technical specs are then specified on the panel.

However oldtrack claims: "his solar panels are only supplying 14.3v x 12amps =171.6watt when they are rated as 204watts =ONLY 84% efficient "
Retyped in simple terms;
14.3v (battery charging voltage) X 12 Amps = 171.6Watts




Do you agree the "battery charging voltage" and N0T the panel voltage, can be used to assertain the wattage of a solar panel ?

Maîneÿ . . .
0
FollowupID: 684067

Follow Up By: Lex M (Brisbane) - Thursday, Apr 22, 2010 at 09:54

Thursday, Apr 22, 2010 at 09:54
I'm sick of this stupidity.
Give up guys. The man's a fool.

"You should never argue with a fool. He drags you down to his level and then defeats you because at that level he's more experienced."

I solemnly promise never to enter into a discussion about solar again if Mainey has posted. Somebody please remind me if I slip up.

0
FollowupID: 684071

Follow Up By: Maîneÿ . . .- Thursday, Apr 22, 2010 at 10:14

Thursday, Apr 22, 2010 at 10:14
Lex,
as you say above your not a "240v electrician or for that matter auto electrician" and you keep refusing to answer questions put to you that will end this hassle, so no loss that I can see as all you do is add more questions to what was originally a very easy question for anyone with some reasonable solar *experience* to be able to answer.

Lex, do you agree "battery charging voltage" and N0T the panel voltage, can be used to assertain the wattage of a solar panel ?

Maîneÿ . . .
0
FollowupID: 684075

Follow Up By: oldtrack123 - Thursday, Apr 22, 2010 at 10:58

Thursday, Apr 22, 2010 at 10:58
Hi All
Now we see Mainet @ his best.
A slight to the question from " efficiency" to "panel rating"

"Lex, do you agree "battery charging voltage" and N0T the panel voltage, can be used to assertain the wattage of a solar panel "

But of course ALL his posts indicate he does not know there is a differance

Yes the man is a total fool

By the way Mainey ,since you are ready to point out incorrect spelling to others perhaps you should get spell check working for you in above thread.
0
FollowupID: 684080

Follow Up By: oldtrack123 - Thursday, Apr 22, 2010 at 11:07

Thursday, Apr 22, 2010 at 11:07
Hi All
Correction to above ,cannot edit


Hi All
Now we see Mainey @ his best.
A slight change to the question from " efficiency" to "panel rating"

"Lex, do you agree "battery charging voltage" and N0T the panel voltage, can be used to assertain the wattage of a solar panel "

But of course ALL his posts indicate he does not know there is a difference

Yes the man is a total fool

By the way Mainey ,since you are ready to point out incorrect spelling to others perhaps you should get spell check working for you in above thread
0
FollowupID: 684081

Follow Up By: Maîneÿ . . .- Thursday, Apr 22, 2010 at 11:19

Thursday, Apr 22, 2010 at 11:19
This post has been read by the moderation team and has been moderated due to a breach of The Personal Attacks Rule .

Forum Moderation Team
0
FollowupID: 684082

Follow Up By: greybeard - Thursday, Apr 22, 2010 at 11:47

Thursday, Apr 22, 2010 at 11:47
Mainey,
What is the measured panel voltage when you are charging your batteries?
Note the question is not what is written on the piece of paper stuck onto the panel but what is the measured panel voltage.
Just to make sure that this is extremely clear and that there is no possible way of misinterpreting the question unless there is some ulterior motive to distract and deflect the subject.

What is the measured panel voltage when you are charging your batteries?

Just in case things get a little muddled by the time we reach the end of this reply.

What is the measured panel voltage when you are charging your batteries?
0
FollowupID: 684088

Follow Up By: Member - Boobook - Thursday, Apr 22, 2010 at 12:56

Thursday, Apr 22, 2010 at 12:56
Mainey, you misquoted me again and importantly left out the following

"The voltage and current out of the panel will change constantly, depending on many variables including load, charger type, temperature etc. "

and

"Less capable and cheaper chargers such as your Stecca are dumber and just try to match the battery voltage with the panel voltage, this means that panels are NOT working at their maximum power point ( ie not as efficient) and in your case it looks like about 84% ( CHARGER efficiency compared to what would be available with a better charger ( eg MPPT) "


Then you added

"In other words the best combination of Amps and Volts to give the maximum power in Watts." Implying that was what you were getting. No No No.

No I never said that. You changed my words. I was arguing that you are wrong and you changed my words to make it look like I agree with you and made your conclusion on my post. Please stop doing that. In fact please don't quote me ever, you never take the full quote and meaning without spinning it 180 degrees.

I am going to have a conversation with my 6 yo now. Much more productive.



0
FollowupID: 684095

Follow Up By: oldtrack123 - Thursday, Apr 22, 2010 at 13:26

Thursday, Apr 22, 2010 at 13:26
Hi Greybeard

I really do hope he will answer your request.
But since he has asked many many times on this & the other thread ,I very much doubt that he will.
His repetive posts ,all on the same stupid line that amps is all that matters shows a very low level of intellligience.
Perhaps it is just a big game to him.
If so that simply means he is a troll
Surely no one is so stupid as to believe every one but him is wrong


Hi Mainey
I at least know when I have mispelt.
You do not
"Lex, do you agree "battery charging voltage" and N0T the panel voltage, can be used to assertain the wattage of a solar panel

_ASSERTAIN
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FollowupID: 684098

Follow Up By: Maîneÿ . . .- Thursday, Apr 22, 2010 at 13:31

Thursday, Apr 22, 2010 at 13:31
greybeard,
I can't answer that in all honesty, because in reference to the 12 Amps being produced by the solar system, the photo as your aware was taken some time ago, I can only guess, or I can state the manufacturers 17v.
Which do you want?
Because I obviously can't tell you what it was when the photo was taken.
It’s not relevant anyway, however I do know it’s not the charging voltage (14.3v) of the regulated battery, and I guarantee you will agree with me on that :-)

Boobook,
I asked you, "Do you agree the "battery charging voltage" and N0T the panel voltage, can be used to ascertain the wattage of a solar panel"

As you refuse to answer, I take it you don't know?
Because you have not corrected the previous posts stating exactly that information.
Or
Maybe you're not prepared to state the obvious, that ALL electrical measurements must be taken direct from the solar panel itself, and not the charging voltage of an unrelated, regulated battery.

Maîneÿ . . .
0
FollowupID: 684099

Follow Up By: oldtrack123 - Thursday, Apr 22, 2010 at 13:44

Thursday, Apr 22, 2010 at 13:44
This post has been read by the moderation team and has been moderated due to a breach of The Personal Attacks Rule .

Forum Moderation Team
0
FollowupID: 684100

Follow Up By: greybeard - Thursday, Apr 22, 2010 at 13:50

Thursday, Apr 22, 2010 at 13:50
to calculate the power at a given point you need current and voltage.
if you have the current and are guessing at the voltage then you are guessing at the power.
the manufacturer provides a voltage and current for the maximum power point of the panel. but it is possible to get the same current from the panel at different voltages. if the voltage is different then so is the power.
No manufacturer will or can state that for the output current you have measured that the panel voltage is 17v.
To say otherwise is one of the fundamental failing of you argument about the power supplied by your panel.
From the numerous epic threads that you've participated in this has been pointed out to you time and time again. You believe otherwise.
Until such time as you are prepared to confirm / deny how close or distant your assumption actually is, nothing will be resolved.

You argue that your assumption about the panel voltage, at a specified current being output by your solar regulator, is the maximum power point voltage of the panel.
Everyone else is telling you that this isn't true. You obviously will not take on board their argument.
You can continue to believe your assumption or you could conduct an experiment and, if you are correct, confirm what you have assumed or it may just confirm what everyone else is telling you.

It's impossible to go back in time to when your original picture was taken, so discharge some of your batteries, wait till daylight and try what we've all been saying.

Your choice.
0
FollowupID: 684101

Follow Up By: oldtrack123 - Thursday, Apr 22, 2010 at 13:53

Thursday, Apr 22, 2010 at 13:53
Hi Greybeard
Well there it is .
Just the answer I expected

But surely he could do it now or have done it over the months this & the over thread has been going.
He was asked that very earlier in the other thread.
AS I have said it wil show similar results as long some amps are flowing,

But ,no he will not do that .
A parrot constantly repeating his set lines
0
FollowupID: 684103

Follow Up By: ModSquad - Thursday, Apr 22, 2010 at 15:07

Thursday, Apr 22, 2010 at 15:07
All,

Have any of you actually realised that this DRIBBLE has NOT once been commented on by the OP? Which Therefore means you have not provided him any relevant information, but more than likely have now prevented people from asking about anything Solar, due to this irrelevant DRIBBLE.

If in the future any further hijacking of any Solar thread in such a manner as this will result in further action been taken by ExplorOz Management.


Regards
The Modsquad
Moderation is just rules

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FollowupID: 684118

Follow Up By: Maîneÿ . . .- Thursday, Apr 22, 2010 at 15:14

Thursday, Apr 22, 2010 at 15:14
This post has been read by the moderation team and has been moderated due to a breach of The Trolling Rule .

Forum Moderation Team
0
FollowupID: 684119

Reply By: paulnsw - Friday, Apr 16, 2010 at 17:05

Friday, Apr 16, 2010 at 17:05
we have a Waeco 80 used as a freezer. Summer can use 86A day and winter 60+. Go out to the camps and powers from bank panels. would need 3 120w panels and back up system. we have new freezers with 100mm insulation on order. 110 Waeco can use 100A day. these things take serious power and more than 190 upright fridge
AnswerID: 413165

Reply By: oldtrack123 - Saturday, Apr 17, 2010 at 10:39

Saturday, Apr 17, 2010 at 10:39
HI aussi

Sorry that this thread has gone so far off topic with regard your original post
Howver false info is worse than none at all .!!
I would agree with Boobook recommendations .

You certainly need a bigger battery in the tug .
A battery should not be discharged below 50% capacicity if you want long life
The fridge will draw a MININUM of 43 amphrs overnight.
EVEN IF the batterry gets fully charged next day,a 100amp hr battery is the very mininum size you would require to keep within that 50% discharge
To run the fridge & recharge the battery capacity used over night for more than a day or two would require ,as a miininum, a 100watt solar panel
This would have no allowance for overcast days when solar output will be much lower.

The freezer temp setting will also heavily influence the amp hrs used ,If as i believe you intend /wish to use it as a freezer
A litle hint . it is much better [more efficient]providing ambient temp is not excessive , to turn the freezer to max when driving &while you have exceess solar power .Then turn it back to a higher setting [ just enough to stop things defrosting ]over night
BUT REMEMBER TO DO THIS AS SOON AS PANEL OUTPUT DROPS BELOW 5amps
This places less draw on the battery which has to be replaced with losses
If you are driving every day then the picture could be somewhat different dependingb on how long you drive for.

I hope this helps & do not be put off by the sidetracks of some who do not have a clue ,if you require further info/advise just ask, there are truely knowledgeable people on the forum

YOU may just have to "sort the wheat from the chaff."
AnswerID: 413256

Follow Up By: oldtrack123 - Saturday, Apr 17, 2010 at 10:50

Saturday, Apr 17, 2010 at 10:50
Hi Aussi

Correction to above:

"To run the fridge as a deep freezer & recharge the battery capacity used over night for more than two or three days would require ,as a miininum, a 200watt solar panel & a 160amphr battery pack"
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FollowupID: 683356

Follow Up By: Steve and Viv - Sunday, Apr 18, 2010 at 13:40

Sunday, Apr 18, 2010 at 13:40
Dead right Oldtrack. The tip to run the fridge as low as you can while travelling (well within some reason) is a great one. It's the same with where the fridge is located, some like it in the car but then put the car in the sun, look at it's location, use a bag if you can and even build a shade cover. Make sure there is plenty of ventilation around the condenser area of the fridge. While I'm not here to argue I want to add. We have a 50ltr Dual Zone. We get 2.5 days out of 156 amps running the fridge at -14 in 32c so the numbers oldtrack and co mentioned *sound right* to me. And even I know the there are laws in electronics and that it that.......
0
FollowupID: 683493

Follow Up By: Alloy c/t - Wednesday, Apr 21, 2010 at 09:53

Wednesday, Apr 21, 2010 at 09:53
Dead wrong if you think changing fridge setting at night will "save" power , what the ---- do you think the thermostat is for ,
0
FollowupID: 683889

Follow Up By: oldtrack123 - Wednesday, Apr 21, 2010 at 11:13

Wednesday, Apr 21, 2010 at 11:13
Hi Alloy c/t

Perhaps you should try it sometimes
It is much more efficient to use the excess available power[from solar or alternator ]to get a cold bank to carry you thru part of the night than to use your battery power
That then has to be replaced with extra power to make up for conversion loss.
Depending on battery type age condition from 20%<40% extra to what was actually used by the fridge

This is something that many overlook when recharging batterys
] If you take 100amphrs out ,you have to put in a min of 120amphrs to replace it
0
FollowupID: 683900

Follow Up By: Steve and Viv - Wednesday, Apr 21, 2010 at 15:35

Wednesday, Apr 21, 2010 at 15:35
Alloy c/t. I'm not sure where that is posted about the lowering of the temp over night and that was not what I was referring to but it is correct. Food drinks etc can exist at 4 c over night no problem but during the day I like my beer at -1 on the fridge temp. So once I've had enough I turn the fridge up and let it idle over night. That is a 5c variance and it does make a difference to battery drain. I'm not sure if there is a calculation to measure amp draw over 1c increments of temperature drop :-)

My point and the one I was referring to as oldtrack noted was that while you are running the car at any time turn it down and let the fridge work it's ring off while it has all the power it needs. This lowers the entire fridge contents and then allows it to relax, sit back and enjoy giving you all those beers once back at camp

The bottom line is the fridge temp will always be trying to equalize with the outside temp so the closer those two are the less the fridge runs. Same for the freezer section.
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FollowupID: 683938

Follow Up By: Alloy c/t - Wednesday, Apr 21, 2010 at 17:31

Wednesday, Apr 21, 2010 at 17:31
Oldtrack + Steve , do you turn your house fridge off at night ? Ofcourse not , same with 12v car /camping fridge freezers .,swapping and changing the thermostat temps uses more power , keeping the freezer full and frozen solid acts as a bank of cold , Steve go to any pub and ask the cellarman what temp the temps are set for beer to be at its best and you will find that from Tasmania to Darwin the the keg room is set at 2c .
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FollowupID: 683957

Follow Up By: Lex M (Brisbane) - Wednesday, Apr 21, 2010 at 17:39

Wednesday, Apr 21, 2010 at 17:39
I wish you blokes would read ALL the words.

Noone will argue that it may use more power. The point is it uses the power during the day when it is available from a source other than the battery.
It uses less power at night where it has to come from the battery.
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FollowupID: 683959

Follow Up By: Steve and Viv - Wednesday, Apr 21, 2010 at 20:19

Wednesday, Apr 21, 2010 at 20:19
Yes Lex M, I know that and that is the point of the tips above re the fridge. Run it hard while you making hay then let it rest at night. And Alloy. I didn't say turn it off did I? I said turn down and at home no, I don't but then I'm not running off batteries and on the beer thing. I love mine at 2c as well but then a gain I wasn't taking about a pub.

Back to Lex's point.
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FollowupID: 683997

Follow Up By: Alloy c/t - Thursday, Apr 22, 2010 at 08:55

Thursday, Apr 22, 2010 at 08:55
Steve , please explain how turning a fridge temp up at night SAVES power ?,,the fridge sitting there all night long unopened cycles less to maintain the preset daytime temp already , now if you turn your fridge temp up at night come morning when you turn the temp down again the fridge cycles ON for a longer period therefore using MORE power to get back to the lower temp ,, absolutly NIL power saving.
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FollowupID: 684065

Follow Up By: Lex M (Brisbane) - Thursday, Apr 22, 2010 at 09:44

Thursday, Apr 22, 2010 at 09:44
alloy c/t please read and try to understand followup 7 just above.
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FollowupID: 684070

Follow Up By: ModSquad - Thursday, Apr 22, 2010 at 10:02

Thursday, Apr 22, 2010 at 10:02
Alloy c/c please heed the advice from Lex M, read the messages from Steve & Viv, and leave it alone.

Any further responses from you would be considered Trolling.

Regards
Modsquad
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FollowupID: 684072

Follow Up By: Muntoo - Thursday, Apr 22, 2010 at 10:45

Thursday, Apr 22, 2010 at 10:45
Looks like we have 2 of a kind.
0
FollowupID: 684078

Follow Up By: Steve and Viv - Thursday, Apr 22, 2010 at 14:42

Thursday, Apr 22, 2010 at 14:42
Alloy. I think by me saying turn it down you took that as colder when I meant turn it down as in less cold or a higher temperature. I'm sorry for that confusion. It's another one of those camp fire discussions Do you turn you air con down, colder or up, colder. Again sorry that bit was confussing.If you look it my post again with that knowledge do we now see eye to eye?

steve
0
FollowupID: 684113

Follow Up By: Steve and Viv - Thursday, Apr 22, 2010 at 14:51

Thursday, Apr 22, 2010 at 14:51
Alloy. Another point. Up here in Broome the temps stay quite hot over night sometimes not getting down to 30 until 5am. It can still be 33 at 12am.

So along with the point that it's best to make your fridge work hard while there is a chance for the power used to be replenished via solar during the day the cycle times don't vary as much as say 25c during the day to 7c over night where I would agree there is not a bigger difference and not as big an advantage as where the ambient temp is hotter.

So I turn my fridge up (warmer) at night in an effort to bring the set temp closer to ambient then once I get up and the panels are working again I turn it back down to my preferred beer temp. Then if I go for a drive I turn it down further (colder) again and fill the fridge with more beer and drinks so again they fridge can draw all it want's while the engine is running
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FollowupID: 684115

Follow Up By: oldtrack123 - Thursday, Apr 22, 2010 at 16:40

Thursday, Apr 22, 2010 at 16:40
Hi Alloy c/t & Steve

I agree this turning up or down can be very confusing.
While certainly not trying to start an argument
I do believe that up means up in temp, down means down in temp irrespective of which way the knob goes
I am sure you will agree that up means "higher" & down means "lower"
It certainly does in most cases.ie tyre pressure ,sound ,volume, speed etc
0
FollowupID: 684124

Follow Up By: Steve and Viv - Thursday, Apr 22, 2010 at 20:08

Thursday, Apr 22, 2010 at 20:08
Sorry guys, no problem. I was going with the down is less in less cooling which really means up :-)

Sorry for the confusion, if I caused any. My thoughts still remain though on that particular issue.

Steve
0
FollowupID: 684160

Follow Up By: oldtrack123 - Saturday, Apr 24, 2010 at 11:23

Saturday, Apr 24, 2010 at 11:23
H Steve
Your post #684115 above makes the point very clear
Provided the excess power,'from solar or alternator, is available it does make a significant difference,by following the procedure you & I have suggested

Another point that should be recognised is that the colder the setting the higher the loss thru the insulation.
This is the advantage of using stored cold overnight ,less drain on battery.
Less power needed to recharge battery[+ efficiency loss] during day ,more power available to make another COLD BANK for next night
I would suggest to anyone who is running near their battery limit to give it ago
BUT just remember to turn back to a warmer setting when panel out put drops below about 5amps
0
FollowupID: 684353

Reply By: Maîneÿ . . .- Tuesday, Apr 27, 2010 at 06:33

Tuesday, Apr 27, 2010 at 06:33
Warren,
When you start looking at Solar panels, look first for a panel stating the required number of Watts required, with two (2) Voltage and two (2) Amp numbers also written on back of panel.
If there is not two (2) sets of Voltage and Amp numbers on the rear of the panel, only one (1) set, then I would suggest you make sure you know what the number actually represents, or walk away and find a more correctly specified panel.

Stated simplistically, disreguard the higher number in the two sets of numbers
generally referred to as:
Open circuit or short circuit (Isc) or (Voc)

You need to take note of the lesser of the sets of numbers.
Max current – (Imp) -or- Optimum operating current (Imp) etc
Max power Voltage (Pmax) -or- Optimum operating Voltage (Vmp) etc

Remember:
Voltage X Amps, produced by solar panel = Watts (power of solar panel)

Example; BP 80 Watt panel
17.6 Volts X 4.55 Amps = 80 Watts

However, if you attempt to use charging battery voltage instead of panel voltage, obviously you will get a much lesser and totally incorrect number, but I'm sure you know that.

Maîneÿ . . .
AnswerID: 414412

Follow Up By: oldtrack123 - Sunday, May 02, 2010 at 12:38

Sunday, May 02, 2010 at 12:38
Hi Warren
All I can advise you to do is carefully read ALL the posts.

Then sort the "wheat from the chaff[rubbish]"
Do not be mislead because some one stands alone & claims every one else is wrong, but I'm sure YOU already can see that.
0
FollowupID: 685272

Follow Up By: Maîneÿ . . .- Sunday, May 02, 2010 at 13:00

Sunday, May 02, 2010 at 13:00
oldtrack123,
mate your like a dog with a bone aren’t you ?

You obviously can't understand it's *impossible* to ascertain the Wattage of a solar system when using the "charging voltage" an unattached aux battery and multiply it by the amps produced by the solar system as you keep on stating, yes that is total "rubbish" and misleading information, but you keep repeating it.

You must use the Amps & Voltage of the solar panel to ascertain the Wattage of the solar panel.

Maîneÿ . . .
0
FollowupID: 685275

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