Leisure battery/fridge question

[fisherman]

I guess there is a low v cut off on the fridge. The peltier is only for sunshine use, or when driving. The battery is showing 13v+ very soon after daybreak, but shows below 12.4v after an hour of fridge and no sun. I'm stuck between surface charge and not enough capacity. Since the battery retained a decent charge over 24 hours disconnected I'm going to try bench charge and have another look. My instinct is to simply add a battery in parallel.

 

[RJJ]

If you add a battery you may help...or you may not. Depends what the problem is...if the solar is chucking out excess power in the daytime that you can't use or store, the a new battery is good. If it helps you avoid damage through deep-discharge, that's good too. But if, as some of the calcs above indicate, your problem is actually with the fridge being hungrier than the daily supply, then you'll still run into problems at some point. Maybe you'll make it to night two. But you'll really need more power supply, ideally something that will help you at night, or less demand.

My useful addition to the good advice above is to remember that your batteries don't even get all of what your solar panels and regulator chuck out. There's reckoned to be c 20pc loss to the internal resistance.

Also and more simply, it's worth remembering the simple stuff like keeping the fridge full of bottled water and minimising opening time. Particularly in the late afternoon/evening when you really want your batts getting their last bit of charge and starting their daily discharge as late as poss