Solar power

Hi all.

Just returned from a weekend test running our new 80lt Waeco freezer fridge, and good but not as good as expected.

The fridge performed great, but I could not keep up with power to feed it, so my current set up is:

100 Amp battery, charged by car when travelling and 110 Amp solar system that was purchased from the doggies at Seven Hills, so it could only be a 80 Amp system.

I jumped on the the Net and found a 150 Amp system (Sharp) for $ 369.00

I assume this would keep the battery charged (on a good day) as we only will be using the fridge/freezer ( 2.9 Ah/HR), LED lights and short time for computer/charging battery charging.

Do you normally run the fridge during the night, or do you turn it off.

All ideas appreciated.

Thanks in advance


Back Expand Un-Read 0 Moderator

Reply By: Sigmund - Sunday, Jan 12, 2014 at 17:20

Sunday, Jan 12, 2014 at 17:20
For a 40 l Waeco run at 4C full time and a couple of compact 12v fluoros we have 200 aH batttery bank. Does the job for 5-6 days off an initial alternator full charge. To extend the time beyond that experts advised a 120 w quality solar panel.
AnswerID: 524372

Reply By: Notso - Sunday, Jan 12, 2014 at 17:22

Sunday, Jan 12, 2014 at 17:22
Depends if you are running the fridge as a freezer, or just all fridge.

If you are running it s a freezer then long term you need to keep food frozen at around minus 14 or so. This would sort of rule out shutting it off at night.

I have only got a 50 litre EVAKool that I run as a freezer and my 140 watt panel seems to handle that and the caravan lights with occasional telly OK.
AnswerID: 524373

Follow Up By: Member - escapesilv - Sunday, Jan 12, 2014 at 17:28

Sunday, Jan 12, 2014 at 17:28
What size battery are you working off.


FollowupID: 805975

Follow Up By: Notso - Sunday, Jan 12, 2014 at 17:55

Sunday, Jan 12, 2014 at 17:55
115Amp Hour AGM
FollowupID: 805979

Reply By: olcoolone - Sunday, Jan 12, 2014 at 17:43

Sunday, Jan 12, 2014 at 17:43
I think your getting confused with amps and watts, batteries, are measured in amphours and solar panels in watts, the two are related but only distantly.

Solar panel rating base their output on the maximum achievable under ideal conditions, these conditions may only appear for a few hours a day and thats if your solar panels are tracking the sun correctly and are not off axis.
AnswerID: 524380

Follow Up By: Member - escapesilv - Sunday, Jan 12, 2014 at 17:59

Sunday, Jan 12, 2014 at 17:59
Yes I do confuse watts and amps, you are correct, but you got an idea of what my issue is.


FollowupID: 805981

Reply By: Member - LeighW - Sunday, Jan 12, 2014 at 18:09

Sunday, Jan 12, 2014 at 18:09
Assuming your 2.9AH fridge consumption is correct your using around 70Ah a day.

Again assuming your panels are 110W units and assuming you have bright sunshine at around 20C ambient then that's around 79Ah production and that will barely cover the fridge.

The above assume 100% efficiency which you won't have, if your in bright sunny condition for 10 hours a day then the ambient is most likely well above 20C and the panel will be producing well less than their 110W maximum, so bottom line is more watts required.

If your running the fridge as a freezer and don't wish to die from food poisoning I would suggest that you don't turn it off overnight.


Lifetime Member
My Profile  Send Message

AnswerID: 524381

Reply By: Brian 01 - Sunday, Jan 12, 2014 at 18:21

Sunday, Jan 12, 2014 at 18:21
Not sure where you got that 2.9 amp info. from (may be an ambitious average) but the Waeco 80 litre fridge freezer draws 7.5 amps, and with a duty cycle ranging from 40 to 70% (highest in hot ambient) you can expect your daily draw to be from 70Ah to 120Ah, the higher figure if using it as a freezer.
Whilst turning the unit off at night is feasible (the interior temperature if used as a freezer is unlikely to rise to dangerous levels) and may save a bit of battery overnight, you will still need to recover any gained temperature, and that will use the same amount of power.
This approach may work if you have excess solar capacity available to run the fridge during the day, but you don't.
The solar panel which I assume is a portable, can be expected to provide a maximum of about 40 to 50Ah per day provided you are very diligent about keeping it pointed at the sun. Expect the lower figure in hot weather.
So, at best the setup is down the drain by 20% and at worst by 80% after the first day, and it's all down hill from there.

Just remember that what you think is full charging off your direct alternator connection is highly unlikely to be so.
Direct alternator charging just does not fully charge remote/second batteries.
Sure, the initial charge rate is impressive, but have another look in twenty minutes and see what it is then and sure, at the end of the drive the terminal voltage may look good, but odds are that what you are seeing is only surface charge and the battery is far from fully charged.
The only way to ensure a good charge into that remote second battery is via a dedicated DCDC charger.
AnswerID: 524385

Follow Up By: Gronk - Sunday, Jan 12, 2014 at 19:52

Sunday, Jan 12, 2014 at 19:52
I don't know why people keep saying you can't fully charge a battery from an can...even with the newer type ones with lower voltages ( although they will take longer )

No wonder people always get confused when batt charging gets mentioned..
FollowupID: 806003

Follow Up By: Member - Frank P (NSW) - Sunday, Jan 12, 2014 at 20:24

Sunday, Jan 12, 2014 at 20:24
Not so, Gronk.

13.2V from my Prado alternator will NEVER fully charge either my crank battery or the second battery or the van batteries.

The crank battery has to live with what it can get. The others need help - and get it.

As you say, it's no wonder people get confused.

Lifetime Member
My Profile  My Blog  My Position  Send Message

FollowupID: 806005

Follow Up By: Member - Frank P (NSW) - Sunday, Jan 12, 2014 at 20:35

Sunday, Jan 12, 2014 at 20:35
And the reason that is so, Gronk, is that the second battery needs 15.5V and the van batteries need 14.4 volts applied to get a full charge. That's what the battery manufacturers say. You cannot argue with it.

The alternator throttled at 13.2 is way behind the eight ball. It physically cannot do it.


Lifetime Member
My Profile  My Blog  My Position  Send Message

FollowupID: 806006

Follow Up By: Brian 01 - Sunday, Jan 12, 2014 at 20:46

Sunday, Jan 12, 2014 at 20:46
Apart from the very valid points made above, the alternator regulator is controlled primarily by the terminal voltage of the crank battery and the computer.
One of the things that the computer looks at is the temperature of that crank battery either by direct measurement or by general under bonnet temperatures, the higher the temperature, the lower the charging voltage.
By contrast, the van battery will be considerably cooler and will need a higher charge voltage. Where's it going to get it from?
Because the crank battery is most likely at a higher state of charge than the van battery, and because it is closer to the alternator, and because it doesn't suffer the same circuit resistances, it will achieve its set terminal voltage much sooner than will the more remote van battery.
This will cause the alternator output to be cut back which will necessarily reduce the charge to the van battery.
It is unlikely that the van battery would achieve a truly fully charged state after 2 days of solid driving.
FollowupID: 806008

Follow Up By: Racey - Monday, Jan 13, 2014 at 09:20

Monday, Jan 13, 2014 at 09:20
Agree with Brian, and that's why DC-DC chargers are needed for that second battery.
FollowupID: 806030

Follow Up By: Gronk - Monday, Jan 13, 2014 at 19:40

Monday, Jan 13, 2014 at 19:40
Oh we go......13.2V is not ideal, and a dc/dc charger would probably be beneficial.....but to say 13.2V won't charge a battery is rubbish, but because it would take a lot longer than an ideal voltage, it's why it's not ideal...

Any voltage that is higher than the terminal voltage of a battery will charge long it takes is another matter..

I have been using the alternator ( as has 1000's of other 4wds ) to charge the batts in several campers ( KK's and now a van ) and have had no probs with getting a FULL charge after a days travel ( and if we are going to split hairs, it may have only got to 95% charge ), and my alternator usually only shows approx. 13.6 to 13.8 V on the scangauge..

If you think you want a dc/dc charger, then there is no problem with that, but to say someone NEEDS one, well that's just not true in most cases !!
FollowupID: 806087

Follow Up By: Member - Frank P (NSW) - Monday, Jan 13, 2014 at 19:55

Monday, Jan 13, 2014 at 19:55
Bye bye ....

Lifetime Member
My Profile  My Blog  My Position  Send Message

FollowupID: 806088

Follow Up By: Brian 01 - Monday, Jan 13, 2014 at 20:16

Monday, Jan 13, 2014 at 20:16
Gronk, you are absolutely correct in your statement that 13.2v will charge a 12v battery.
In fact the basic chemistry voltage of a lead acid cell is 2.15v, so anything above 12.9v for a 6 cell 12v battery will charge it.
The problem arises when you add a bit of voltage drop or extra internal resistance of a not so young battery into the mix.
A 13.2v starting voltage allows you just 0.3v before you are at that minimum level. Even if you lose just half that level you will be quite a lot older before that battery comes up to full charge.
Modern voltage controlled alternators often go even lower than 13.2v, so there is virtually no chance of getting even a reasonable charge from them.
FollowupID: 806090

Follow Up By: Gronk - Monday, Jan 13, 2014 at 20:43

Monday, Jan 13, 2014 at 20:43
Yeh, that's why I said 13.2V is not ideal..

And why some people with newer type "smart" alternators use a replacement diode fuse to get their voltage up 1/2 a volt..

I've got no problem with dc/dc fact I would use one myself if I thought I needed one..
FollowupID: 806092

Follow Up By: The Bantam - Tuesday, Jan 14, 2014 at 00:11

Tuesday, Jan 14, 2014 at 00:11
This.."Wont fully charge" issue is a very interesting one, and not as simple as many would like to believe.

Saying that you will never fully charge a battery off a car alternator is to say the least an unreliable statement.

Go to you battery specificatoion sheet....if that sheet specifies a "float charge voltage" of 13.8 volts that is all that is required to fully charge that battery, and most likley lower.

BUT, it will take time....maybe quite a bit....time you may not have........this is why we run higher charge speed things up.

My current alternator charges at 14.2volts.

There are other issues, like charge resistance, what is considered fully charged and certan battery chemistries.

But the blanket statement that you wont fully charge a battery off a car alternator is outright BS.

The issue with the original poster is simple...they are drawing more current out of their battery than they are putting in.

Standard issue par for the course, what is it, the third or forth thread this week with the same issue.....underestimating the current demand of the fridge, overestimating the capacity of the battery and over estimating the output of the solar pannel.

Back to the maths.
40 litre fridge run as a fridge, requires an absolute minimum of 100amp hour battery and 150 to 180 watts of solar panel to be at all reliable.
Jump up to the bigger fridges, say the word "freezer" or have bad habits and the whole game gets more expensive fast.

FollowupID: 806116

Reply By: MEMBER - Darian, SA - Sunday, Jan 12, 2014 at 23:08

Sunday, Jan 12, 2014 at 23:08
Once your research has you up to speed with the amp hours and watts etc., note also that the wattage figures on solar panels are their 'rated' output under perfect conditions...and such outputs are rarely achieved (70% of that rating is a realistic max). As for saving power at night...we often turn our fridge down a bit at night but run it hard during the day, as the solar comes in.
AnswerID: 524413

Reply By: exploreaus - Monday, Jan 13, 2014 at 09:18

Monday, Jan 13, 2014 at 09:18
I travel quite a bit with a similar fridge/freezer.

I have never bothered with solar.

It is much cheaper just to run my 4wd for 15 minutes if the power in the second battery is getting to low.

I have set my fridge to run on a "low voltage" setting.

AnswerID: 524427

Reply By: Aussi Traveller - Monday, Jan 13, 2014 at 09:53

Monday, Jan 13, 2014 at 09:53
Hey escapesilv the best way to get the right information is not these forums, especially about solar panels etc, as you might have noticed lots of replies and no 2 agree.

Go to an auto electrician and speak to them as these people are trained in this field and can give you a no bullsh1t response the first time.

AnswerID: 524430

Follow Up By: Brian 01 - Monday, Jan 13, 2014 at 10:14

Monday, Jan 13, 2014 at 10:14
I'm not sure when you last spoke to an Auto electrician about solar power, but you would be lucky to find one in ten who even know how a solar panel really works.
Throw in a few questions about MPPT chargers, knee curves, impedance matching, etc. and watch their eyes roll back.
I have had this type of discussion many times with Auto elecs, and most can't even get their heads around the fact that you can short the outputs of a solar panel without it self destructing.
Auto electricians are trained to deal with auto electricals, and as yet that doesn't include solar.
FollowupID: 806032

Follow Up By: MEMBER - Darian, SA - Monday, Jan 13, 2014 at 10:24

Monday, Jan 13, 2014 at 10:24
You obviously don't know the Exploroz forum Phil. If you take the time to become more familiar with the knowledge and experience contributed here, my guess is you'll use less insulting language next time you post. All the best.
FollowupID: 806034

Follow Up By: Aussi Traveller - Monday, Jan 13, 2014 at 11:31

Monday, Jan 13, 2014 at 11:31
Brian, after reading many posts over several days on solar panels, deep cycle batteries and how to get them to work for all my needs on this and other forums, it was easier to go to an Auto elec and get them to do it.

It took him a day to mount and wire up a battery, set it all up to the two Engel's and supply me with a solar panel to run it when the car is turned off, all of which is automatic.

I have been using this system now for about 7 years with no problems, in fact it has worked for up to 8 days (my longest stay in one place without power from memory), with no hiccups at all.

If I ever need to have it fixed who do you think I will go to, someone who is able to set it up or ask someone on a forum what should I do.

Darian, I have been looking on this site for many years, it astounds me how much info on here is either completely wrong or out right dangerous, not all but a hell of a lot, besides most of the posts on here now days are either repetitive or off topic, My opinion.

Just do a search on solar or batteries and read all the past threads, you will not find one that has at least 3 people that can agree on a set up and how to make it work.

Now I don't know how solar panels and these set ups work, and neither do most people here based on the fact that no two post agree, so my post in regards to going to a professional to get it done is appropriate.
FollowupID: 806043

Follow Up By: oldtrack123 - Monday, Jan 13, 2014 at 13:09

Monday, Jan 13, 2014 at 13:09
HI Phil
Did you ever think you might just have been lucky??

Generally speaking ,as Brian said ,they have little knowledge of solar or most electrical matters!!
Yes some MAY be able to do a SIMPLE instal
But most are just AUTO electricians! [that is THEIR field of expertise]

WE ,WHO KNOW,have heard & seen the results of many auto electricians work & recommendation!!


FollowupID: 806046

Reply By: Ross & Gail - Monday, Jan 13, 2014 at 12:48

Monday, Jan 13, 2014 at 12:48
I had the same issue with my 80L
Run on -17 all day and -12 at night.
Have two accede batteries. 80a & 250a
Have just purchase a 195 foldable solar system and have no issue of getting absobtion with full sun in three hours

I am not technical as it took me 12 months to get this far as the conflicting information in surprising

I am also going to change my electrics to DC-DC
AnswerID: 524440

Follow Up By: oldtrack123 - Monday, Jan 13, 2014 at 13:19

Monday, Jan 13, 2014 at 13:19

Anyone is allowed to give their OPINIONS on forums

THOSE opinions may /or may not not be valid

AND YES even technically qualified persons may not fully agree with each other,
But usually they are more prepared to go into detailed discussions, for one simple reason, they have the knowledge to DISCUSS the subject
They are most likely also prepared to expliain, in detail ,any further /follow up questions.,

Be wary of those who cannot /will not do that

But it is always a question of "sorting the wheat from the chaff"

FollowupID: 806047

Follow Up By: Aussi Traveller - Monday, Jan 13, 2014 at 13:53

Monday, Jan 13, 2014 at 13:53
This is my whole point oldtrack, there are people that know and a lot more that don't, so how does someone who doesn't know work it out ? so my point above was to seek proper info from someone who does

To answer your question above, no I don't think I was lucky, I asked this person could they do the job had he said he could, there are many other auto elecs that I know that could do the same.

WE ,WHO KNOW,have heard & seen the results of many auto electricians work & recommendation!!

So are you and auto elec or a solar panel expert ? the above statement is not clear, see this is the question most people that give all this info say that their info is correct, but none put their qualifications out there for so the person wanting to know can make an informed decision.

If people have info or would like to discredit someone else's info, they should put up their qualifications to prove it, that for starters would cut 2/3s of the crap responses out there, it would probably stop a lot of think they know it all people from clogging up the forums with their crap, and those that don't know may finally get some decent and proper info to work with and until that happens I will go to someone that actually knows their stuff.

I'm not having a go just putting my thoughts out there.


FollowupID: 806052

Follow Up By: Brian 01 - Monday, Jan 13, 2014 at 14:11

Monday, Jan 13, 2014 at 14:11
Phil, I agree that it can be difficult to get to the bare bones of an issue.
The advantage that you have on this forum is that should someone post information or advice that is incorrect, there are ample qualified persons watching who will soon make that point known.
This does create confusion in itself, but at least you read all of the arguments and it should not be difficult to see who can substantiate their side of such a debate.
You will always get those few who choose to see only what they want to see, and that is sadly unavoidable.
There is always more than one way to tackle any issue, some are right, some are almost right, and some are downright wrong. The wrong ones will soon become evident by the clamour it creates.
Who's going to tell you that your auto elec is giving the wrong advice.
Certainly not him.
By all means use him to do the job if you so desire, but asking the questions here at least gives you a bit of insight into what to expect.

Collyn Rivers has a regular column in a popular auto electricians' journal where he attempts to educate them on these very matters, not sure they would be paying him to do that if they already knew it all.
FollowupID: 806054

Follow Up By: oldtrack123 - Monday, Jan 13, 2014 at 15:32

Monday, Jan 13, 2014 at 15:32
HI Phil
RE {quote}So are you and auto elec or a solar panel expert ? the above statement is not clear, see this is the question most people that give all this info say that their info is correct, but none put their qualifications out there for so the person wanting to know can make an informed decision.{end quote]
Posting qauls on a forum does not mean a thing
,Icould claim I was anything & there is no way of disproving it!!

The details & wiiingnes to go into details can be reasonable guide

But those who just post some lines & are not be prepared to dicuss it are the ones you should aviod .
YES, there are a lot of CRAP responces but they are usually recognisable as such.

But just to anwser your questions on Quals
Brian is an ELECTRICAL engineer

I am an old retired electrician ,50 years in the trade & still keeping up, who has a very wide range of experience over many ,many facets of the trade
Elecrical supervisor , head service technician for a co selling a very large range of electrical & engineering products,
Yes SOLAR experience as well
But more importantly I can read & understand electrical subjects texts ,manuals ,RULES, etc
That was very important whenever the Co sold a NEW type of product

FollowupID: 806064

Follow Up By: Ross M - Monday, Jan 13, 2014 at 16:50

Monday, Jan 13, 2014 at 16:50
Aussie Traveller
Seeing you only want info from someone who you think or trust has the expertise, you may possibly have to eat your hat if some of the folk on here posted their qualifications. Looks like Peter Q has.

Because someone has "AUTO ELEC" over their doorway is something you instantly respect. Fair enough but many auto elecs aren't very good and sometimes very ordinary. You were lucky with your install.
Like mechanics around 9% actually gain a really recognized qualification which indicates a meaningful understanding of the principles in that field which also includes auto elec TOO.
Most mechanics are stuffed when an electrical issue occurs, Dealer usually DON"T employ the finest so unlikely to have much joy there.

A Solar Expert as you say, is only someone who has leaned stuff to be knowledgeable in the subject, others can learn it too, the hard way or by examining info and deducing what is reality and what works by having an ability to understand it all.
Solar and it's use and the energy from the sun is so variable most comments are a guide and there is no surety all will work for all situations unless you use the "elephant gun to kill a mouse" concept of overkill.

Understanding the theory is how many of us determine what to say to someone like you who may not understand so you are guided as much as possible via this electron method of problem solving.
Face to face we could show you so much more you would be have brain fade just after 5 min of our show and tell.
FollowupID: 806069

Follow Up By: oldtrack123 - Monday, Jan 13, 2014 at 17:13

Monday, Jan 13, 2014 at 17:13
HI Ross
just a little story based on having good theory & fault finding abilities
I am NOT an AUTO electrician , but some time ago Grandson had a strange problem with his auto electrics

He took it to an auto "electrician" who claimed he had fixed it but the NEXT day it was no better
I did a few tests, used some theory came to a conclusion where the problem lay
Wrote it all down & gave it to Grandson to take back with the car
The auto electrician said to him ,No that could not be the problem.
But later,after some hours of work ,decided he just might follow my line
Yes I WAS ON THE RIGHT TRACK ,30miutes & a replacement part the problem was fixed.
He then asked the grandson did he know how I had come to my conclusions

What was realy involved was being able to think outside the square, using sound fault finding procedures AND THEORY

I think you understand, IF the electrical theory is sound ,one can understand & sort out most electrical problems .
But some times it may need specilised test equipment OR the swap & replace technique, which seems to be the common way these days.

In that situation, one often end up paying for parts that were not in need of replacement.

FollowupID: 806072

Follow Up By: Aussi Traveller - Monday, Jan 13, 2014 at 17:33

Monday, Jan 13, 2014 at 17:33
Once again Ross you have jumped on a thread and blurted out a useless and non helpful response, thank you for your condescending rant without any attempt to answer the OP question.

As said above I didn't think I was lucky at all, I used my nous and spoke to a professional, I then paid a price for a professional job that has stood the test of time, had it not they would have heard loud and clear that I wasn't happy.

I do not need to eat anyone's hat as I didn't actually have a go at Brian or Peter, I just asked what if any qualifications they may have had to which they replied, my point was that if you posted on here or other forums with some good info followed up with your qualifications people could the decipher between the truth and the bull sh1t.

Seeing as you have been on many threads blurting out your opinions without actually offering an educated answer, I am beginning to think you need to go back to school and stop trolling these forums, this thread like all the other solar panel threads was going down the same(you can't be right because I am the only one that is right track) so my input was to speak to a professional and get the right info without all the white noise in between.

Now Ross if you have nothing to contribute to this or any other thread I may post on the I would appreciate you keep your opinions to yourself.

FollowupID: 806074

Follow Up By: Ross M - Monday, Jan 13, 2014 at 18:51

Monday, Jan 13, 2014 at 18:51
Without going for the jugular I will point out and dispute items which many accept as true but aren't the way the system or industry works.

The idea, is to help the person/s who want to get out there and are on a limited budget and must, in many cases, do work themselves after finding out some info. Such people can't afford to just roll up and have it done for a price because they haven't got that amount of extra $$$ but do deserve a chance to experience the outdoors too.
Without some guidance they can't achieve their dreams.

I can't work out why it is all too challenging for you to believe something different to what you think is the norm.
FollowupID: 806084

Follow Up By: Brian 01 - Monday, Jan 13, 2014 at 19:23

Monday, Jan 13, 2014 at 19:23
Phil, I haven't mentioned my qualifications anywhere in this thread.

Qualifications may give you a claim to knowledge, but many on here have that without the qualifications, just an ability to assimilate information gained from their experiences.

I don't get in the habit of saying that I have such and such qualification so therefore I must be right.

I am quite content to make my point and allow others to pick it apart as they see fit.
If it can't stand that test, and I can't justify my reasons for coming to any particular conclusion, then I just may be either wrong or a very bad communicator.
Either way it certainly gives me some exercise for the grey matter and someone may learn something from it along the way, if that is me, then well and good.
The next time I may give better advice.

I remember that I once thought that I had made a mistake..But I was wrong. lol

There are always those among us who, no matter how much good information they receive, absorb none of it and so do it their way anyhow, often totally contrary to the advice given.
That is their prerogative.

A wise man once said that experience is something that you gain just after you needed it most.
Fortunately asking questions can often stave off unfavourable experience.
FollowupID: 806085

Follow Up By: olcoolone - Monday, Jan 13, 2014 at 20:09

Monday, Jan 13, 2014 at 20:09
Ross, why do you hate everyone with qualification?

It seems no matter what it is you bag trade qualified people and ones who have made a successful business out of it.

According to you you should not trust anyone with a piece of paper or letters after their name!
FollowupID: 806089

Follow Up By: Ross M - Monday, Jan 13, 2014 at 20:52

Monday, Jan 13, 2014 at 20:52
I don't hate everyone with a qualification, but do object to ones who have "some" qualification ripping people off, so I mention the pitfalls of the situation. Lots don't do that and let people be taken advantage off. It does get down to integrity and many are qualified and act and do work which is never in question and provide good value for work done.
Others trade on the fact they have a certain degree of quals and do unacceptable work and overcharge for the work done.

Any alert as to how the unsuspecting or those not close to those trades can get a job done without being fleeced is a good thing to do.

Often a successful business isn't the result of giving good service.
You read things which aren't there.
I never said, not to trust anyone with papers or letters after their name, you decided that.
I know and respect businesses local to me who do good work and peoples holidays and lives depend on their work, sadly it isn't a high percentage.
FollowupID: 806093

Follow Up By: olcoolone - Tuesday, Jan 14, 2014 at 19:19

Tuesday, Jan 14, 2014 at 19:19
Thats right i forgot a business is not aloud to make a profit, many forget that profit you boss makes goes to the employee in wages and also provide employees with good working conditions.

Note: treat all customers as a charity.

I am sure you would of been happy in your working life to take a pay cut so the customers you were providing a service to could save some more money, not many people like you Ross who would do that, its something you should be proud of.

A customer will pay what they think is far by choosing the business they get to do the work.

In the real world many get stung by paying to little ( its called a bargain) and using the shonky businesses leaving it up to the better businesses to pick up the peaces. We get many call from people like this who want us to fix the screw up and do it cheap as they have already paid once, we have little sympathy for them.

The real shonks who are out to rip everyone off is few and far between as eventually they fade away....... But the cheap shonky one seen to survive, might have something to do with every one is after a bargain.

Ross on two occasions you have said 9 out of 10 trades people you would not trust and yes there are many good businesses built on offering fantastic customer service and offering outstanding work at sensible prices.

Sounds like you have a grip with anyone who is going to make a profit out of you.
FollowupID: 806155

Reply By: johno59 - Monday, Jan 13, 2014 at 13:40

Monday, Jan 13, 2014 at 13:40
Hello guys, I went through this ordeal 12months ago. It was fun to get everyone's advice and I learnt a lot but in the end was getting nowhere and more and more confused! I found a good auto electrician, told him what I wanted to achieve ie what 12 volt items I wanted to run incl tv,lights,deep freeze/fridge ( Waeco) and PC. He set it all up and we have a system now that works. It cost about $300 for a separate cable from the car to the deep cycle battery in the Van,the battery itself, $250 and a 120'watt solar panel connected to the van $280. We haven,t yet ran out of power with careful use and the waeco keeps everything cold or frozen. My wife even has a hair dryer she runs for a few minutes!!! Go find a auto electrician that understands this stuff. It's a lot less stressful and in my case a bloody lot less confusing johno
AnswerID: 524445

Follow Up By: oldtrack123 - Monday, Jan 13, 2014 at 15:35

Monday, Jan 13, 2014 at 15:35
Often a PM to the ones who seem to be giving the best answers[not necessarly the ones you may want to hear] may get some better results

Many do that !!!

FollowupID: 806065

Follow Up By: Member - escapesilv - Monday, Jan 13, 2014 at 21:58

Monday, Jan 13, 2014 at 21:58
Hi Johno

what size is the deep cycle batter and fridge/freezer you have.

Cheers Rob.
FollowupID: 806107

Follow Up By: Member - LG__ (WA) - Tuesday, Jan 14, 2014 at 23:53

Tuesday, Jan 14, 2014 at 23:53
Hi Johno59

Am I right in assuming you have power going to the deep cycle battery from the alternator of your vehicle (via the $300 cable from the car to the van) and the solar power tops up the battery on the days you are sitting still and not driving anywhere?

We recently did a trip 3 week trip using just an 120amp AGM battery and the vehicles alternator via a 150amp Projector isolator kit and 175w anderson plug.

We were only running a small Waeco (35lt) set on 0°C and a few led light strips. Using cryovac bags for the meat was brilliant as it meant I didn't need to freeze anything while were on the road (initial and mid trip purchases of meat).

The only time the indicator on the powered battery box went from Green (full) to Orange (med) we did a quick trip from the campsite to a lookout - all of 10kms each way - and the indicator was green again.

Granted, we only stayed still for 3 days at most then travelled at least 50km to the next camping spot so there was regular recharging happening from the alternator.

It was also mild Spring weather. No doubt, if we were to 'park up' for a week or two in the middle of Summer our situation would need more than the alternator alone can supply :)
FollowupID: 806184

Follow Up By: Brian 01 - Wednesday, Jan 15, 2014 at 09:02

Wednesday, Jan 15, 2014 at 09:02
LG, just be aware that the indicator is only voltage driven, it has no idea of the true Soc of your battery.
What I mean by this is that you could take the battery, almost flat, charge it for a little while until the surface charge builds up on the plates, at which time the indicator will go green, and you will think the battery is fully charged.
Leave it sit for a while and the indicator will show a very different picture as the surface charge is absorbed into the plates.
FollowupID: 806197

Follow Up By: oldtrack123 - Wednesday, Jan 15, 2014 at 12:52

Wednesday, Jan 15, 2014 at 12:52
In adddition to the above from Brian
A battery may indicate a full /high SOC by VOLTAGE
But have very little actual Amp h capacity

That is where a load test is necessary to confirm it's ACTUAL remaing capacity
The cause of this effect is loss of active material on the plates.
What remains can/does fully charge & give a good SOC reading but it has no capacity
eg a 100Ahr battery could NOW be effectively only 10Ahrs battery

FollowupID: 806228

Follow Up By: oldtrack123 - Wednesday, Jan 15, 2014 at 12:55

Wednesday, Jan 15, 2014 at 12:55
Cannot edit But should add
EVEN a heavily SULPHATED battery can be fully charged by SOC readings, but again have lost a major proportion of it storage capacity

FollowupID: 806229

Follow Up By: Member - LG__ (WA) - Wednesday, Jan 15, 2014 at 19:41

Wednesday, Jan 15, 2014 at 19:41
Thanks for the follow ups fellas
I will guess that Soc stands for State Of Charge...

Brian - How then should people monitor the soc if not by the little lights on the battery or the battery box?

PeterQ - By load test I think you mean, hook all the widgets in the world to it and see how long it will last?

Does it make any difference to the monitoring methods if you have solar charging as well as battery or dc-dc charging?

I can't go down the road of 'expensive complicated gadgets' so simple and reasonably priced (pension rate) suggestions appreciated

It is a brand new dual battery system (battery, battery box & isolator) as well as a borrowed Waeco (our old Engel is nearly 40 years old and not quite reliable enough for 'self sufficient' situations) so I was trying to keep a close eye on it, just in case :)

I did notice that the battery wasn't charging up when the light went orange after just 48 hours and 'himself' tracked it back to an aftermarket optional switch that is supposed to stop the power going back to the battery inside the vehicle cab when not needed.
It was an old switch and not able to cope with the task at hand.
'himself' removed said switch from the system and everything worked fine after that (afaik) :)

I was blissfully unaware that my full battery may not really be full, now I am double guessing my next trip and the battery systems ability to cope with keeping the fridge cold during summer heat.
FollowupID: 806267

Follow Up By: Brian 01 - Wednesday, Jan 15, 2014 at 20:52

Wednesday, Jan 15, 2014 at 20:52
Unfortunately there is no easy or cheap way to know the true state of charge (Soc) of a sealed battery.
The only really effective way is to have a battery monitor that allows you to input the capacity of the battery into its functions.
If it doesn't have the facility to input the capacity of the battery then it will be no good for your purposes.
The simplest of these devices just add and subtract power in and power out to keep abreast of how much is left.
The problem is that you always have to put back more than you took out to get back to full charge condition.
The better (and more expensive) devices allow for this, but a cheaper one will still give you a reasonable indication, you may just have to reset it every so often to remove accumulated errors.My comment was regarding some posts that are made that have absolutely nothing in common with the discussion at hand.
Some simply have only one word in the post, which has often had me wondering why it was even posted.
Now I know why.
There was no intention to belittle anyone who has reached this milestone.
A correctly connected monitor will account for all charge and discharge activity to keep an accurate record of remaining capacity and Soc.
You will see some cheap monitors that measure amp hours in and out, but unless you are willing to do the math yourself, you still won't have much idea of true Soc.
A correctly installed monitor will read all charges from different devices and all discharges, and correctly compute you remaining battery capacity.
FollowupID: 806270

Follow Up By: Brian 01 - Wednesday, Jan 15, 2014 at 20:54

Wednesday, Jan 15, 2014 at 20:54
Sorry about the double up at the bottom of my post, one of the problems with an Android tablet, you run out of room on the typing page and then can't see or edit what goes off the screen...Really poor design.
FollowupID: 806271

Follow Up By: Member - LG__ (WA) - Wednesday, Jan 15, 2014 at 21:16

Wednesday, Jan 15, 2014 at 21:16
Thank you Brian
I will pass on your comments to 'them that know' at the shops and gratefully accept their guidance based on said criteria ;)
FollowupID: 806273

Follow Up By: Brian 01 - Wednesday, Jan 15, 2014 at 21:35

Wednesday, Jan 15, 2014 at 21:35
Gee just reread my post, I don't know where all that crap in the middle came from, I certainly didn't type it in there.
FollowupID: 806274

Reply By: Tonyfish#58 - Wednesday, Jan 15, 2014 at 19:46

Wednesday, Jan 15, 2014 at 19:46
Hi Rob - I Have had the Waeco 80 ltr for about 8 years now.

In the end this is what I needed to keep it running on Fridge/Freezer for extended times at rest in a camp no Alternator. In case of issues I have the Yamaha 1kva 4 stroke Genset and have needed it a couple of times because of Battery and Regulator issues.

I have 2 x 115 amh Deep Cycle Batteries specifically for the camper lighting and fridge (very few lights) - These have a feed from the alternator.

I run the fridge on High during the day when the sun is shining and turn it down to low overnight. I keep some type of insulation over the freezer being careful to still allow the flow of air to the fridge.

I have an 80w fixed Solar panel and a 120w folding panel which I move with the sun during the day.

This is the only way I can camp knowing I can run the Waeco 80 ltr, anything less and it just did not get there!

One full day and maybe a night I would get with only the 80w Fixed Panel and alternator Charge, mostly it would switch to fault low charge before the morning. Not until I added the 120w folding panel did I have success in running independant of a generator and alternator.

Hope that helps Regards Tony
AnswerID: 524576

Follow Up By: Member - escapesilv - Thursday, Jan 16, 2014 at 09:31

Thursday, Jan 16, 2014 at 09:31
Thanks Tony.

That was the information I was after, do you have the batteries interconnected between themselves or do you have to swap over when one is getting low.

Cheers Rob
FollowupID: 806306

Follow Up By: Tonyfish#58 - Thursday, Jan 16, 2014 at 20:37

Thursday, Jan 16, 2014 at 20:37
Rob - I have them wired together as 12 volt system. Both the solar regulators and the Alternator (Through Redarc Isolator & Anderson Plug) are connected in to the system.

I have a clip on Battery condition Monitor that seems to work OK, it does show when the sun goes down that the fridge has to be turned down :-)

One Battery would just not do the Job! I have them permanently on the front of my slide off camper, so I can go put the boat in and fish and leave the camper in camp!

Best of luck with your setup - Mine works great with the capacities i mentioned.

Regards Tony
FollowupID: 806362

Reply By: Member - Jo Q (NSW) - Friday, Jan 17, 2014 at 12:38

Friday, Jan 17, 2014 at 12:38
Hi Rob,

I am far from technical, but below is what I have/used. I only used the solar panels for the first time over this Xmas break & I didn't run out of power at all. Used LED's most nights & the fridage was in the back of the ute with temps outside hovering around 28 degrees most days.

I have a 50ltr Waeco that I run on about minus 4, my 2nd battery is 110 amp/hr & my solar panel are 140 watts.

All the above posts are a tad confusing for me & it took me ages just to get the general gist of solar/amps/watts....

Good luck with it all!
Cheers :)

AnswerID: 524663

Follow Up By: The Bantam - Friday, Jan 17, 2014 at 18:10

Friday, Jan 17, 2014 at 18:10
You may not have "run out of power", But in my opinion your system is either on the verge of not keeping up, or it does not in fact keep up at all...but you have not run it long enough to find out that it does not keep up.

You are almost certainly cycling your batteries deeper than recommended for a long service life.

You are running your unit as a fridge...-4c is a low fridge temp and is not safe or recomended feezer temp...for safe freezer temps think -18C or lower.

28C is not hot outside.

Are you suplimenting with charging from the vehicle alternator.

Many solar systems do not infact keep up, they just delay the inevitable or prolong how long the system will run off a charge.

This is not bad as long as it is recognised for what it is.

There are lots of people out there with systems that do not keep up or just keep up under favorable conditions...AND think their system is fine..
They typically go away for week ends or a week max.

Then they go away for the "BIG trip" or the long break and find that over a longer period that the system slowly and chronicaly fails.

Day after day the batteries either get deeper and deeper into discharge because they never get fully charged or they get cycled too deeply every day and the batteries fail far earlier than they realy should.

If you ever run into your low voltage protection cut out( if you have one) or your fridge stops, your system isn't just a bit behind the game, is very badly behind the game because you are cycling way too deep.

FollowupID: 806445

Reply By: Member - Jo Q (NSW) - Friday, Jan 17, 2014 at 20:27

Friday, Jan 17, 2014 at 20:27
As mentioned, I am far from technical. But a few points;
My fridge was run at minus 4 as a fridge, not a freezer. When operating as a fridge/freezer it is set to minus 18.
Whilst 28 degrees is not that hot, that temperature increases dramatically inside a car sitting in the sun.
The above comment was made in relation to a 2 week stay where the car would have been lucky to have done 80km's
Yes, the fridge has a cut off and the dual battery an isolator.
I guess waiting for the "big trip", that does not include those already done (the Simpson x 2, Cape York & 3 weeks around SA ex Sydney), will test my system.
My post was not a recommendation, merely a comment on my current experience based on my set up and fridge.


AnswerID: 524696

Sponsored Links

Popular Products (11)