AGMs Alternators and Amp hours

I also suggest that you crank up the thermostat (colder) on the fridge when driving. This will reduce the power consumption of the fridge when stationary. It shouldn't affect the charging rate of the battery while driving.
Gerry

That sounds like a great tip!

The amount of drain (load/things you have turned on etc) while driving does have an effect on charging times.
stereo, aircon, lights, frig etc etc all add up and that is charge that isn't available to be put back into the battery. Again it also depends on the vehicle, alternator size/output and the batteries SOC.
Another idea I've seen done is to run a smart charger(Ctek or similar) off an inverter which then charges the auxilary battery. This was in a caravan battery situation where the inverter ran off a 12v supply from the vehicle and then the charger ran off the 240v side of the inverter.
You would have to do some maths to work out whether this was particularly efficient but it would certainly charge the battery properly.

Hi Peter,
Re charge rate, you're right (I was talking in general terms) as regulators are not perfect, but lets assume that he has a 100-120A alternator in his 4wd (most do). 4A drain from the fridge will make a small difference to the charge rate, but not much, especially once the initial charge drops off into the battery.
The stereo will only have an effect if he has installed a doof-doof machine :-)

What I'd like to see on the market is a 12V input version of the Ctek to charge AGMs; ie, without having to generate 240v first, which incurs a double conversion loss from 12v.
Gerry

I am no sparky but I learned some electricity doing amatuer radio licence.

Consider this. The car alternator will try to keep 13.8 volts on the system regardless. The modern alternator, I am led to believe, is capable of supplying around 80 - 120amps. At 13.8 volts the target battery is not going to pull any more than 15 amps and mostly a lot less according to internal resistance, capacity and state of charge. (all related) the biggest drain apart from charging, will be the headlights (100watts eight amps? each) and spotties.

I dont think any thing you operate in the average vehicle is going to affect the charge rate. In my opinion. no arguments please just facts and I will stand humbly corrected.

Owen

Owen, I humbly endorse what you have said.

The alternator/regulator endeavours to maintain about 14 volts at its output and therefore at the battery terminals. (ignore small volt-drop) The alternator is capable of supplying about 100 amps and has a regulator to protect it by reducing the output voltage if the current exceeds this value.

After a normal engine start the battery terminal voltage will be somewhat below 14 volts and the current flow from the alternator to the battery will initially be in the order of 40 amps. As you say, this value is dependent on battery conditions. At this stage the current regulation of the alternator is not active as the charging current of 40 amps is below the set limit.

The alternator acts essentially as a Constant Voltage charging system and the charge current will progressively reduce as the battery voltage rises until at about 14 volts there will be no further charge current into the battery. It is now behaving as a battery on float.

While all this charging is taking place there may be other loads consuming power such as refrigerators and headlights. They are nominally 12 volt devices but will operate at the 14 volt level satisfactorily and will draw their appropriate current from the electrical system, perhaps around 20 amps or more. So the alternator is now being called upon to supply 60 amps, still below its limit of 100 amps so the current regulation is still not called upon. Accordingly, the voltage at the battery terminals is still 14 volts and the charging current into the battery is unaffected by these other loads as you have said. If there is a secondary (deep-cycle) battery also requiring charge then its load will be added to the alternator and the current load will increase accordingly.

If the total load on the system exceeds the alternators limit of 100 amps then the output voltage will be reduced accordingly and the battery charge rate will then suffer and the voltage supplied to the other loads will similarly be reduced. But this is not likely to come into play in normal use.


Because the system operates as a Constant Voltage charging system the charging current is asymptotic, that is, it reduces progressively. This extends the charging period and is also not the ideal charging pattern for a lead-acid battery. A multi-stage charging pattern would be far better. As Gerry (joc45) has said a 12 volt input version of the Ctek would be beaut but to set up a system using an inverter and 240v Ctek would be expensive, bulky, and inefficient. I think the Arrid Twin Charge is aimed at maintaining a constant nominal output voltage but does not perform multi-stage charging characteristics. Actually, I cannot find out much technical information about it at all.

A further difficulty arises if as usual the auxiliary battery is of a different type to the cranking battery, eg AGM type, and ideally requires a different charging regime. This could be overcome if a 12v input Ctek were available devoted to just the auxiliary battery and it would act also as a battery-isolator. There is a real market opportunity here! (Thinks...... must write to Ctek)

Incidentally, Gerry's proposal of lowering the fridge temperature setting whilst travelling and raising it again when at camp is very effective. I have been doing this for some time with great results............ an ice-cold beer upon arrival and reduced battery consumption whilst camped. If the beer starts getting warm again then I just have to break camp and move on. LOL

Hi Allan,
Whew! I was trying to keep it brief, but you've said it all.
Well mostly all; I just wish to add that my Nissan alternator regulator (and probably other makes as well) senses the 12v right at the battery, then via a feedback wire to the alternator regulator, rather than sensing the voltage at the alternator output terminal. This therefore takes into account any voltage drop between the alternator and the battery. The voltage regulation is therefore even better, ensuring the battery maintains the correct charge voltage over a wider range of loads.
Now I bow out.....
cheers,
Gerry

Hi Gerry,...Well.......'Just the Facts Maam' (you are probably too young to recall that quote !)
Even then I left out some, like external voltage sensing. Yes, it does eliminate sag at high current and is of value when the high drain is due to system load rather than battery charging load.
And I expect someone to pick on my use of 14 volts as nominal !!

Hi Allan,
You're showing your age, but I think we may be of similar vintage!
I recall the TV show was Dragnet, subsequently parodied by Stan Freburg.
Thank goodness they don't show that sort of thing any more, tho I would be happy to sit thru episodes of Get Smart!

I chose to refer to 12v, so I wouldn't get picked on! But (showing my age again) I do recall back in the days of 6v Volkswagen Beetles, there were battery mfr's who made an 8v battery for them to compensate for the appalling voltage drop thru the car's wiring. The regulator was re-adjusted to charge accordingly. What a difference! The lights lit up, the wipers wiped, the flashers flashed. Bosch were highly critical of the mod (they would be!), but hey, I saw a few happy VW owners.

cheers
Gerry

Ah yes Gerry, St George and the Dragonet. I had forgotten all about Stan Freburg.
And Agent 86 missed it by 'that' much!

That was fascinating about the 8 volt batteries in Volkswagens. I never knew that!
As I recall, the battery was under the rear seat and the generator in the 'boot' with all the consumers up-front so the juice did have a fair way to travel.

I did short-out a failed cell on a 6 volt battery once and ran the vehicle on 4 volt until I could get a replacement battery. The cell had actually exploded internally. A salutary lesson in the power of hydrogen!

While using some form of step up charging is theoretically going to give your battery(s) a better charge, this is only true if you drive long enough to allow the battery to reach a fully charged state.

No matter what set up you have most people rarely drive long enough to fully charge their auxiliary/house battery(s), so it is far more important to replace as much of the used capacity as possible in the time available while driving and in most cases, an alternator will easily replace more than anything else will.

In Wesley’s case, if he has a 100 A/H battery that is at 60% Soc when he starts his days drive, a 20 amp step up will charge his battery in the same time that the alternator, if the battery is higher than 60%, the 20 amp step up will charge the battery quicker.

If the step up device is smaller than 20 amps or the battery is at a lower SoC, then an alternator will fully charge the battery quicker but in any case, this is only so if you drive long enough, if you are not putting in long hours of driving then the alternator only set up will replace more of the used capacity in short drive times.

Wesley also floated the idea of having two 100 A/H batteries, if this is the case, the batteries only have to be less than 80% Soc and an alternator will charge the batteries quicker than a 20 amp step up.

Furthermore, if the two batteries are at 60% Soc then the 20 amp step up will require around double the driving time to fully charge the two batteries as compered to what an alternator can do.

Being as most people commonly take their auxiliary/house batteries down to 50% SoC or less, while free camping, in these situations, using a step up device is actually more likely to be detrimental to the batteries as compered to what an alternator can do.

Whoops Allen! "lowering the fridge temperature setting whilst travelling and raising it again when at camp is very effective." Sorry but dont feel too bad I get things back to front all the time.

They used to do a single cell to add to a six volt too. I had a Chevvy truck I used to crank because the starter motor was not up to it. It would have been pretty easy in those days to change the whole system to 12 volt and some did.

Six volts also coped badly with poor earth connections as they used to do them through the body work. My 12 volt 1975 torana had problems! I had to clean the rust from the headlight earths to get them to work. I think putting current through body panels had something to do with the propensity to rust as well the dissimilar metal trims they used. I notice modern vehicles dont rust like they used too, and I suspect not just because they use better undercoat.

Owen

Hi Owen, I think I got it right. I "lower the fridge temperature setting whilst travelling". i.e. I set the thermostat lower. At camp I have it at 4c and when travelling set it at minus 10c ..... that's lower (colder).

Gerry said "crank up the thermostat (colder) on the fridge when driving"
"Crank up" is a euphemism for "increasing the power" of refrigeration, which will cause it to get colder. We are both saying the same thing I believe.

But we crank up the thermostat (colder) on the fridge when driving.

But we are getting away from the original thread posting methinks.

"I think putting current through body panels had something to do with the propensity to rust as well the dissimilar metal trims they used. I notice modern vehicles dont rust like they used too"

Modern cars have EVERY electrical load (except the starter motor) have their earth return go via a connection to the body.

I would hope that their product quality is better than their website quality control. Here are just some examples on their website, I could not stand viewing all pages!

"designed of fully charge"

"The unitis now"

"thrid generation"

"as they forn"

"lives easyer"

"and are Australian made or Imported products."....... Is there some other source?

LOL

hi all
i have been using an arrid twin charger and it's extremely successful and so far has'nt give any problems
i found it easy to self install it is placed on/in the camper/caravan near batteries and very quiet when running
it will take alternator voltage as low as 9volts from your vehicle alternator and boot it back up to 14v

so that you can completely top up charge in deep cycle batteries on a camper/caravan

it's connected between the vehicle/trailer using anderson plugs it is activated via vehicle ignition via a relay

the 12volt shop in perth is where i bought mine from and it was $300.00 about 2yrs ago

Allan B

I don't see any problems, what parts are wrong.. :-)

Only went to school to eat my lunch..

Richard

Fantastic, its all coming together in my mind now, the blog was extremely useful! Ill sleep on this tonight and hopefully make a firm decision tomorrow. just wish my budget was bigger ;)

Maîneÿ

I believe your arthmetic is a little out.
A 40 watt solar panel will supply approx 12 Ah per day. Not enough I don't think.

Lex,
I realise it's no good to ask you to please explain why you believe my mathematics is "a litte out" as I'm sure you won't.
As you have previously refused to answer direct questions put to you, for me to wast time again in an attempt to explain how a solar panel would work as I've stated, would only be a waste of time and electrons.

I won't try and explain why your maths are wrong, because you obviously believe your numbers are correct, so you have a gr8 weekend.

Maîneÿ . . .

Maîneÿ

The original post stated a usage of 48.440 Ah (per day) before the need to recharge.

A 40 watt solar panel has an output capability of approx 2 Amps in good conditions. (Assuming a good efficient non MPT regulator.)

The excepted number of peak solar hours in a day is approx 6 depending on which part of the country you're in.

6 X 2 equals 12 Ah. If you can get 48.440 Ah per day out of a 40 watt solar panel, you know something that the solar power industry doesn't.

Lex, you have to remember why this information is required in the first place.

First thing is the original poster stated possible usage of 2 ah, now don't you think that's a bit high, according to Engal / Waeco quoted sales numbers, they claim ~O.8 ah

Second, it's required for a 6 month trip round the paddock.

A reasonable quality 40 Watt solar panel will have an output of >2 Amps for at least 8 hours ( 8 x 2 = 16+ Amps )
However they are rated @ ~2.3 Amps, I'm only using 2 Amps as an example.

Now do you understand it just a bit clearer ?

Maîneÿ . . .

Maîneÿ

I think I'm wasting my time here and I apologise to other posters, but perhaps you could reread the question you're replying to.

"First thing is the original poster stated possible usage of 2 ah, now don't you think that's a bit high, according to Engal / Waeco quoted sales numbers, they claim ~O.8 ah"

Nowhere has the original poster said what type or model of fridge it was that I can see.
From the waeco web site for a cf80 :-
"Av. Power Consumption: 2.9 amps/hr (@ 12V, 5°C fridge, -15°C (approx.) freezer, 32°C ambient temperature)" (Unfortunately even Waeco can't get the units correct for their consumption figures, so I'm assuming they mean 2.9 Amphours per hour.)
So in answer to your question I don't think its high. 2Ah per hour is not unusual. This is a common fridge rated by the manufacturer higher than that.

The question asked assumed a usage of 48.44 Amphours per day and I don't assume to tell the poster what he should have asked. I try to answer the question that is asked. Maybe you could do the same.

"Second, it's required for a 6 month trip round the paddock. "

Where did you get this gem of information, I can' find it in this post?

"A reasonable quality 40 Watt solar panel will have an output of >2 Amps for at least 8 hours ( 8 x 2 = 16+ Amps ) "

Have a look at this map http://www.solar4power.com/map8-global-solar-power.html and point out to me where you get 8 peak solar hours a day.

No ( 8 x 2 = 16 Amphours ) but I know many people can't seem to grasp the difference between Amphour and Amp or that meaningless "amp per hour".

"However they are rated @ ~2.3 Amps, I'm only using 2 Amps as an example."

2.3 amps is a typical maximum power output rating for a 40 watt solar panel.
2 Amps is a good real world figure for a 40 watt solar panel. Unless you're assuming bright sun with some cloud cover and a solar panel tracking the sun. So I stand by 6 X 2 = 12 Amphours per day as a workable average figure. One that can be relied upon for real world conditions. Not a figure that will leave some camper wondering why "the battery went flat".

Incidently, I have logged an 80 watt Monocrystalline panel with a pwm solar regulator running into an AGM battery with a constant load keeping the regulator in bulk charge mode for maximum input, in the Brisbane area (average peak solar hours 4.5 to 5 per day). No fancy tracking, just real world conditions. My testing gave me a real world AVERAGE figure of close to 25 Amphours per day. From the peak sun hours map I believe that is indicitave of the performance for a large part of central Australia. Expecting more than that leaves no room for a bad solar day.

"Now do you understand it just a bit clearer?"

Maîneÿ, I find this sort of condescending comment offensive.
I suspect I understand it much clearer than you ever will, and I've probably forgotten more about electricity, electronics, solar panels, batteries etc. than you will ever know.

Your answer to the original question asked, telling someone a 40 watt solar panel will do what they want is misleading in the least and I would only hope that they get some more reliable advice before implementing your recommendation.

As you said -
Now do YOU understand it just a bit clearer?"

(Please excuse speling errors, the spellchecker is having one of those server eror fits at the moment"

Lex,
the link you have posted in some vain attempt to make your point, is not even relevant, as it shows where I live in West Australia as having only 3.5 PSH.
The link states it is only showing the "average *LOW* PSH" not even the *average* let alone the High PSH.

Remember it's showing PSH and N0T *total* sun hours, with this the results assume there is absolutely no sunshine at all, other than of those 3.5 PSH, here in West Australia, and I'm sure your aware that this is definitely not the correct information to use when attempting to ascertain the total wattage of any solar system.

For example my solar system is delivering *some* Amps to the AGM's from as early as 7 AM till well after 6PM and 24/7, well outside the 3.5 PSH claimed and these extra Amps would be well in excess of double of the PSH Amps.

As to fridge power consumption Engel actually states their *60 lt fridge/freezer combo* runs @ 0.5 to 4.2 AMPS Maximum.

Lex, you use the following information, though technically it may be correct for a fridge *N0T* connected to a charging device, "Av. Power Consumption: 2.9 amps/hr (@ 12V, 5°C fridge, -15C (approx.) freezer, 32C ambient temperature)"
You and I both know those numbers are N0T even relevant when charging from a solar system, well I hope your aware they are incorrect, but maybe that's the problem and you actually don't know it?

Then you state:
" where did you get this gem of information, I can' find it in this post? "
I had stated: 'Second, it's required for a 6 month trip round the paddock'

Lex, just because you can't find any reference to his " trip round the paddock " in the post is not relevant, even though it is true.
Why don't you simply ask the correct questions and then get the relevant answers, then tell me my "gem of information" is in fact true and correct.
It's relevant information to the original poster and how he will charge his battery system while on his "trip round the paddock" after all that's why he has asked the original question, not because he wants to go fishing down the beach one afternoon.

Yes, I concur with what you say: I also think I'm wasting my time
but at least I've made some attempt to correct your inaccuracies :-))

Maîneÿ . . .

Maîneÿ . . . posted:
"A reasonable quality 40 Watt solar panel will have an output of >2 Amps for at least 8 hours ( 8 x 2 = 16+ Amps ) "

- If you want to have some crdeibility in electrical matters, you should at least use the correct units.

Mike,
will you please enlighten me to what you believe are the "correct units" terminology in the post you have quoted as being wrong?

Maîneÿ . . .

. . so you're saying you don't know what the correct units are ?

Mike,
I've asked you to correct the "unit" terminology if you think it's wrong

After all your saying the "unit" terminology I used is wrong - not me

if you feel you can't answer my question that's ok :-)

Maîneÿ . . .

Don't go there Mike, you're flogging a dead horse. :-)

Maîneÿ . . . posted:
"Remember it's showing PSH and N0T *total* sun hours, with this the results assume there is absolutely no sunshine at all, other than of those 3.5 PSH, here in West Australia, and I'm sure your aware that this is definitely not the correct information to use when attempting to ascertain the total wattage of any solar system.

For example my solar system is delivering *some* Amps to the AGM's from as early as 7 AM till well after 6PM and 24/7, well outside the 3.5 PSH claimed and these extra Amps would be well in excess of double of the PSH Amps. "

Here you demonstrate that you don't understand the concept of peak-sun-hours.
It's explained in a post below.

"Maîneÿ . . . posted:
I've asked you to correct the "unit" terminology if you think it's wrong "

- Those of us here who understand electrical units, know your units are wrong.



"if you feel you can't answer my question that's ok :-) "

- the point is, we want YOU to demonstrate that you know the absolute basics of electrical units, but you can only confirm you don't.

Mike,
You posted:
"A reasonable quality 40 Watt solar panel will have an output of >2 Amps for at least 8 hours ( 8 x 2 = 16+ Amps )
- If you want to have some crdeibility in electrical matters, you should at least use the correct units."

OK, whatever you say Mike, but I don't want *crdeibility* whatever it is ?
Do you eat it or drink it ??

We both know the only "electrical units" stated are "Watts" and "Amps"
and yes, we also both know they are used correctly relative to the post
Sorry but I've nothing to prove to you :-)

Maîneÿ . . .

Maîneÿ . . . posted:
"A reasonable quality 40 Watt solar panel will have an output of >2 Amps for at least 8 hours ( 8 x 2 = 16+ Amps ) "

Including the units -
8 hours x 2 amps = 16 amphours

It should be clear that if you multiply amps by hours, the resulting unit cannot be amps again, it's amphours.

For some reason people have difficulty accepting that the internationally accepted unit of Electrical capacity or charge is amphours - not amps, not amp/hours, but amps.

Mike,
I hope you make up your mind about the correct terminology?

You have made the exact same mistake you tell me I’ve made

It’s either ‘amphours’ or it’s ‘amps’ as you have posted below

You have clearly stated:
“ For some reason people have difficulty accepting that the internationally accepted unit of Electrical capacity or charge is amphours - not amps, not amp/hours, but amps ”

yes, that's what I said "Amps" with a capital "A"

I think it's better if you don't get too pedantic with terminology, then make the exact same mistake yourself.
We know what you mean, it’s not a problem as some accept we are human and make spelling mistakes etc.

Maîneÿ . . .

Hi Wesley,

You could put the fridge on the front seat and Jo under the tonneau. LOL
Gotta keep that beer cold.

Certainly, the cooler you can keep the fridge's ambient the better it will perform but if there is no alternative........

If the tonneau is the usual black it will absorb and re-radiate heat inside the tray. You could try some additional insulation around the fridge cabinet. A reflective surface is helpful against radiated heat so you could try one of those silver reflective panels used to block sunlight through the windscreen. They have an insulating core too and are much cheaper than the proprietary fridge covers. Fold it to fit over the fridge without blocking the ventilation openings.

Years ago, I made my Engel more efficient by completely surrounding it with 2" styrofoam sheets, glued with liquid nails. Gaps were left for the ventilation of the condensor. Worked well, as 2" foam would, but geez, it squeaked on rough roads!
cheers, Gerry

Gerry, it must have looked god-awful.

I'd describe it as neat but not gawdy!

Think ill try that second option Alan! ;)
Were just going to monitor it. if it gets to hot we'll rip the tonneau of.
As long as the beer is cold.

Yeah, the second option could be a lot cheaper in the long run.

Ok Maîneÿ

So up above you said
"A reasonable quality 40 Watt solar panel will have an output of >2 Amps for at least 8 hours ( 8 x 2 = 16+ Amps )
However they are rated @ ~2.3 Amps, I'm only using 2 Amps as an example. "
Your panel I believe is 200 Watt. 200/40 = 5. So your 200 Watt panel should be outputting 10 Amps "for at least 8 hours a day" by your figures and yet it never got above 8.6 Amps before 1PM.

And now your saying that in the real world your 200 Watt solar system "in previous 12 hours has collected 29ah " I believe a 200 watt system would be rated at about 12 Amps. 12 X 3.5 =42. Derate that by about 30% because the panel is flat. 70% of 42 = 31.5 It would appear you got slightly less than 3.5 peak-sun-hours today.

For anyone who doesn't understand the term peak-sun-hours, here is a definition.
"The equivalent number of hours per day when solar irradiance averages 1 kW/m2. For example, six peak sun hours means that the energy received during total daylight hours equals the energy that would have been received had the irradiance for six hours been 1 kW/m2."
The map referenced above shows the average condition so it would be less in winter, more in summer.

Back to the question.
Therefore logically a 40 Watt system in the same conditions would have given 5.8 Ah.Thats even lower than my estimate of 12 Ah. It would appear we both got our arithmetic a little out.

So on those figures and the original question from Wesley of how to supply 48+ Ah your recommendation would have to be for at least a 300 Watt solar system, not a 40 Watt. A simple error.

Would that be correct?

Or let's look at your figures above again :-
7AM 3.8 Amps.
9AM 7.5 Amps.
1PM 8.6 Amps.

Let's say your panels output at least 7.5 Amps from 9AM to 1AM, it was more than that by your figures above.
That's 4 hours X 7.5 Amps = 30 Ah. Plus whatever was before 9AM and after 1PM. At least 7.6 Ah between 7AM and 9AM. plus some more after 1PM. So your panels output more than the 29Ah shown above, and that 29 Ah figure gives no real indication of what your panel is capable of. I would expect a 200 watt system mounted flat like yours, in the real world, to do over 60Ah on a reasonable day this time of year. (Maybe you need to investigate the problem with yours.)

So you have once again demonstrated that you may have some idea of how solar systems work, but no idea of how to measure the real capability of same. And I would warn anyone to be careful about excepting your recommendation on a solar panel size for their requirements after the above example.

One last question. If Wesley in the original question only needed a 40 watt panel to supply 48Ah a day as advised by you above, Why do you have 200 Watt? How many fridges do you really have? Your profile only shows one.

Lex,
Please get your head out of the books and look what I've actually posted above.
I did preference my post with the following:

"With my SÖLAR system laying horizontal on the roof it starts recharging the AGM battery system at dawn.

25th October 2009, real life information as panel *NOT* cleaned "

This information * IS * relevant and was included so it could be easily understood it was not to be taken as a perfect example of how a solar panel works, but obviously you don't read or understand the relevant information that is posted solely for the benefit of understanding the final results.

They were the results on the day, with the relevant conditions, however if you look at some of the pictures on my ‘profile’ you will see actual pictures of the system exceeding 12 Amps.

Unfortunately you have simply multiplied the hourly Amp numbers I've quoted, * ASSUMING * the same Amp number was available for the full hour, to get your numbers, however they were NOT the same numbers for the FULL hour, they were the numbers showing at exactly the time the readings were taken each hour.
For instance with-in a few seconds of the 7 am reading the Amps went UP but they were not record as the higher number, likewise at many times the numbers were very much lower than the number shown at the HOUR that they were noted, because of the overcast conditions during the day.

That is one reason why my numbers don't match with your numbers, another is because your numbers are purely mystical and not accurate in any way at all, because you have *assumed* (wrongly) that the Amp number you have multiplied is available for the full hour, as I’ve said they were not, but I would think anyone with some solar experience would know the Amp numbers will continiously change during the day anyway, or don‘t they tell you that in the books you read?
Also you can't compare one solar panel directly to another of a different type and capacity and expect to get an accurate understanding how the second will perform, the maths will tell you one thing but in life the numbers are not relevant, as these numbers prove to you beyond all doubt.

The Amp numbers quoted were from bird dung splattered solar panels that sit under trees and don’t get the attention they deserve, yes it never got to 12 Amps because it was laying flat and it was also very dirty, never mind it does the job intended of it.

Do I need to explain how many times the fridge stopped or started too, even though it’s not relevant in any way to the numbers posted anyway.
I use a 200 Watt system because I did buy and sell AGM batteries and solar systems, but that’s not relevant to the post in any way either.
No your not being "set up" I'm for real, you set yourself up :-))

Maîneÿ . . .

OK wahatever you say Maîneÿ. I give up.

(Shaking head and walking away.)

:)
sure is what I'm going to do Alan.
Ive taken in as much info as I can to make the best choice I can. My system will be simple and unfortunately limited by budget. Solar, while obviously a solution is well beyond our means if I was to get the required amount of panels. A second battery is still possible, I plan to use up to 50% SOC then pack up and shoot for powered sites.
For the record and I should have mentioned it earlier my fridge is a 47L Evakool Fridge/Freezer run only as fridge.
I got my usage for the fridge just as an average from 0.7 and 2.3 from the evakool site plus some just in case.
I am going on a, hopefully, 6 month road trip with the better half Jo.

A bad holiday is better than a good day at work

Thanks all,

Wes