dual battery amp hours?

[ericjn]

Hello All-

My wife and I are planning a road trip from Colorado to Argentina this fall. I've been looking into a dual battery setup.

I know there are a million dual battery posts, but mine is specifically about amp hour battery choice.

We will have a 60 watt solar panel, and be able to charge from the alternator, say every 3 days at least. Planning to have a 300w inverter to run a laptop and a phone charger. We will have a small fridge and a few small lights.

I'm planning to use a CTEK 250S dual for charge controller/ battery isolator. My question is how many amp hour battery do I need to buy, and does anyone have recommendations for specific batteries?

Thanks a lot!

 

[jdinevens]

probably best to ask that here there are a lot of people that can answer that question better than I can. But first I'd calculate out what your power users will be, laptops, fridge, lights, etc... and then figure out total power draw per day in amps, then you can figure in how much your solar panels will add to the system. Also remember whatever batteries you get to divide the AH rating on the battery in half as batteries don't like being drained past 50%......that should get you started...