I think you'll need a charge controller to go between the panel and battery. Something needs to control the charge rate and voltage.
You can also wire (2) 12V batteries in series and get 24V, but will probably need a charge controller here as well.
There are 24V pumps around. Vertex has a nice one. Gast, and I believe, Thomas has them as well.
I'm just learning this solar stuff as well, but haven't dug too deep in the lower voltage DC stuff for charging batteries. That's on the list tho, but want to nail down the higher voltage AC stuff first.
I'll have to find out which charge controller my camper has. It would be nice to park it out back and spend the summer. AC during the day and DC at night, well, that's the goal. I think it will be a lot nicer than running a generator.
