you may want to
try this first.. i use the same type on my mini ride on but the 24 volt version.. your batteries will take 2-3 days to charge, but it is better for your batteries to slow charge.. your batteries will have a longer life span that way..as long as you don't need it you mower the next day this will work.. and changing you gearing to a 3 to ! ratio will help even more for a longer range on your cutting...