I’ve mentioned that a year ago I bought some used 6v (golf cart) batteries for basically core price. I limped along with them since then, but the last month’s heavy use finally did them in.
I’m shocked they lasted this long. When I got them they were watered but had been stored discharged for months; they have voltages in the 2.x range (ie, seriously dead/sulfated).
For the past couple of weeks they’d been getting “thirstier” for water which is usually a sign of imminent demise. I could have nursed them a while longer but winter would not have been kind to them. So I replaced them with the identical batts: Duracell 6v 220Ah flooded. The battery is made by Penn/E.Deka and has both a good reputation and a good price. Kind of a sleeper.
Off the top of my head I think the recommended setpoints are:
Vabs == 14.6v
Vfloat (standby) == 13.2v
Vfloat (deep cycling) == 13.8v
This should hold me until I retire, at which point I will likely go lithium. Shouldn’t do it now since they shouldn’t be charged below freezing, and it freezes often in ELP in the winter.