Solar Test, the final result

Great Stuff Jimbo, glad you're happy with your results thus far, I'm sure the villains will help you give it a real work over :)

Lyn

Jimbo, this has been a very interesting thread.
What was the distance from the solar panel to the fridge & the size of the cable used?

Thanks,

John

Gooday Jimbo,

I don't reckon you will be up with us on Boxing Day, aren't Supercheap having a sales Boxing Day only?

Cheers mate...see you after Xmas.

Jimbo, I should have said the distance between your solar panel & battery?

John

Hi Jimbo
Been following your progess over the last month or so,seems like you might have found a balance for your needs there....

I've have the same 80l waeco so it's great to here this info.Thinking of going the same way now "solar,AGM" instead of genie.

Like to here how it goes in the wild.

Keep up the good work..

Pete

Hi Jimbo this is a great idea what you have done, it has certainly given me something to think about in reguards too solar. We decided not to go solar when we were setting up our 12v in the camper mainly because of the advise we recieved about the size of the solar panels and power they had too be (ie)160w two 80w panels, thanks for the post on your test of the panel very helpful.

Eat pie hl.

See you at Murry Sunset Jimbo.

Baz.

Dear Jimbo
Congratulations on your experiment. I would however sound like a couple of notes of caution. I have seen too many people try to make small solar panels do too much. They end up disappointed with a short battery life and high overall running costs.

I would point out couple of facts which may mean your real life performance is not quite as good as you experienced in the Test.
1.As you point out the days you performed the test were good to excellent days for solar output. The average Melbourne December day would not produce as many Ahrs

2.Late December is the optimum month in Melbourne for Solar output ( December 6.42 January 6.67 equivalent hours of sunlight) . The performance at other times of the year will be significantly worse. In April for instance the equivalent Sola hours have dropped to 3.69.

3. Amorphous solar panels put out about 10-15 per cent more power when new than their ratings suggest. If your panel is new it will be performing like a 70-75 W panel. They settle down to the manufacturers claimed output over a few months of use in sun light.

This is how the theory would predict your performance on an average December day in Melbourne.
The manufacturers claim your panel will put out 3.8 amps.
This would therefore give an output of 6.42 X 3.8=24.4 Ahr .
Amorphous panels are less affected by heat and shade but we still have losses for temperature, cabling the regulator etc which means on an average December day in Melbourne you would be doing very well to get much more than 20 Amp hour's out of your 64W solar panel.
If you are stopping for 2.5 days at a time you can pull out another 15 to 20 Amp hours a day out of a deep cycle 100 Ahr AGM battery, without dipping to the level of a very short life.
Lets assume you have 40 Ahr over 24 hours. This means your total average consumption for the fridge camp lights music etc needs to be under a 1.7A average.
The above calculations only rough, but I have been optimistic. They are averages with a reasonably high standard deviation . On some days you will do much better but not consistently. This means unfortunately that to avoid damaging the battery with a deep levels of discharge you need to provide more output and storage capacity ( or an alternative energy source such as a back-up generator ) than the averages would suggest.
Over many years of use in it my own system I have shown that these calculations are not just theory, but do work in practice.
I don't have experience with the type of fridge you own. I will therefore leave it to others to comment whether your set-up will be viable in the long term.
I wish you well Jimbo but I fear you are asking too much from your set up. You are better to buy an adeqate solar output before deep disharges shorten the life of your expensive battery.
Cheers John

Jimbo,

IMHO a brilliant test and yes even a realistic result as well, considering you had next to nothing in the fridge to retain the cool.

As to needing a bigger panel in the real world? well you may or may not, as you can comfortably get a (high) trickle charge into your battery with only one 64watt panel, naturally two will only be better and maybe possibly all that is required for your setup, remembering you did not have to start the engine of your vehicle during your "test" to add outside voltage.

It is good to see a practical test instigated by a "beginner" prepared to spend time and have a go, and geting the result that is expected from those with experience is just the bonus.

Good on you.....