I am working on designing a portable water filtration system for rafting. I got my idea from this system but it costs $1,800. My idea is to get a 'under cabinet' filtration with UV disinfection set up. They even make a 12v version. Now this system requires a minimum of 20psi so I'd need this pump to push the river water through it. The UV claims 14w@12v and the pump says 4A@12v. I believe this means I'd have a 62w draw.
The thought is to charge the batteries via solar during the day (while floating down the river) and power up the pump and filter while at camp. Since the unit theoretically can produce 2gal/min we wouldn't need to run it very long each day. I'd assume a max of 1 hour per day (30min morning/evening).
I was planning on using a couple of 8Ah batteries from Cabela's. This should have enough storage for 3 days without charging (cloudy days). However, I just read a post by hay4man regarding Li-Ion batteries saying they are