Whatever batteries you choose, just be sure to get real Deep Cycle batteries that were designed for many discharge and recharge cycles, and add enough amp hours so that you only discharge the batteries down to no less than 50%. Many "Marine" batteries are not "Deep Cycle" and are designed to start the boat and perhaps run a few electronics. AGM (non-venting) batteries are best if you will be installing them in the living area. If the batteries are well vented, then Lead-Acid batteries will likely give you durability at a lower cost. I used two 6v Trojan T-105RE Lead Acid batteries in series for 220 Ah at 12 volts installed in the front locker on my 25B21RB and after two months on the road with only the rare plug-in, found they hardly discharged with just an 80W solar panel
. Of course LED lights
and the stereo were about the only power I used as I don't have an inverter. I plug a small digital volt meter into the 12v power outlet and never let the batteries read less than 12.3v with the power turned off. That's approximately just over 50%. Check out https://handybobsolar
.wordpress.com if you want more info that most of us can process.