I’ll be using my electric golf cart ($600) batteries come from local junk yard ($30 each has 4) my RV friend is getting me 4 solar panels to mount on roof to keep them charged up. For the price of those bikes (which I like) one big 48 volts lithium batter can be had cheaper and it last 20 miles on a charge. Maybe something to think about (I dislike having to put gas in one)
Lithium batteries are pretty cost effective these days, you can get a 300AH off amazon that will last 20 years and remember, lithiums can be run down to zero, where lead acids / AGM get damaged going down to just 50%. A single 100AH (very cheap) would likely out perform those used lead acids you're using, and not need to be replaced.
I have 460 Amp Hour in my RV, thing will outlast the water now and the solar keeps it topped off (by noon). Even no solar it's good for 5~ days using everything. 460ah is the equivalent to about 18 car batteries
