At work we have a quantity of 12v sealed lead acid batteries used for field kit. Is charging them with a decent car battery charger a sane idea? Can they all be parallelled up to one charger for a float charge? We're currently experiencing the difficulties you'd expect - flat batteries being left flat, sulfated batteries staying in circulation etc.
Depends. Some are crap and will overcharge or trickle charge once done which is bad, some are fine.
Can
Best way to charge them is with a 3 stage or 4 stage decent switch mode charger individually first. . Once charged it should be stored along with all the others in a parallel string with a 13.2 to 13.6 volt constant voltage on float. With healthy batteries only a couple of amps is needed even for big strings of batteries. As long as one with a shorted cell or something isnt added.
Check with voltmeter to see if your big parallel string is kept at constant
13.2 to 13.6. Not higher! This string wont correctly charge them no matter how long you wait, because the voltage isnt high enough to equalise the individual cells. Thats why a decent charger that charges them to 14.4v should be used first. But once charged the string at float voltage will prevent deterioration as much as possible and keep them fully charged.MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.