Solar panel sizing for twin 105 amp batteries

Tim,

This article here will help you to work out your electricity generation requirements.

Cheers,

Val

By my reckoning you will need maybe 20aH per day as your biggest possible 12v output is on Gas !!
So based on 20 aH per day you need a 5 Amp reg and 100 watt panel should be OK - However once you plug that fridge in to 12v - this all changes dramatiically -
by 200% !! ( roughly ) .

There is a spreadsheet available for calculation of solar requirement on my website and if you were a member it is accessible in the members file area here ,

Cheers

Steve

Tim

You should be able to keep the batteries topped up by charging from the car alternator - if you are moving regularly. You may need a solar panel for when you're camped fopr longer stays.

Peter

Tim,
I would go with the recommended 100 Watt panel, but lesser would be ok for short durations, the solar regulator has to be able to *regulate* the current (Amps) going into it from the panel, so if it's a 100 Watt panel you need a reg about 7 Amp MINIUM.
If you decide on a panel with a rated output, in Amps, of ~4.6 Amps (80 watt panel) then get a 5 Amp regulator – minimum, remembering that you may get extra solar panels in the future, it's less expensive to use a better quality, higher capacity regulator from the start.
The regulator being a higher capacity will NOT charge the battery any faster than a lower capacity regulator.

Look first at a decent regulator with an LCD screen, because you can see what is happening in the way of Amps available from solar system, Amps going into the battery, Voltage at the battery and history of charging, etc.
Then compare that to a lesser expensive non LCD screen reg.

Do NOT get a cheap 'on/off' regulator, get one just like any good quality 3 or 4 stage battery charger, that has at least trickle, float and boost characteristics.

Maîneÿ . . .