If the metal plates were exposed your batteries are probably shot. Yes they might charge up but will not stand up to a load.
My suggestion is to get two 6 volt golf car batteries with at least 200amp/hr rating. You can find them at places like Batteries Plus, Sam's Club and other places.
BTW you can , and should use a 12 volt charger/maintainer to keep your batteries in top shape. I use this one..
https://www.amazon.c...ding=UTF8&psc=1
If you'd like I can take a picture of my set up tomorrow.. just let me know
Edited by smlobx, 30 August 2018 - 11:29 PM.