Charging tips?
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Noah
Jun 20, 2011, 11:24:08 AM6/20/11
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Thinking out loud here, and inviting comments from those with more experience than I:
If one were to wire up a bunch of SLA batteries in parallel, can a normal multi-stage "intelligent" car battery charger juice them all up at the same time, assuming they're all similarly drained? Truck batteries can be 100 amp hour or more, so I don't think there'd be a problem if we hook a car charger up to six 12A/h batteries in parallel.
I also have a ham radio bench power supply that throws out 13.8VDC up to 250 watts. It'd take forever to charge a deeply cycled cell at that voltage, but I'd imagine it's good for keeping them topped off.
Anyone have more battery charging tips or advice for the new guys on the list?
If one were to wire up a bunch of SLA batteries in parallel, can a normal multi-stage "intelligent" car battery charger juice them all up at the same time, assuming they're all similarly drained? Truck batteries can be 100 amp hour or more, so I don't think there'd be a problem if we hook a car charger up to six 12A/h batteries in parallel.
I also have a ham radio bench power supply that throws out 13.8VDC up to 250 watts. It'd take forever to charge a deeply cycled cell at that voltage, but I'd imagine it's good for keeping them topped off.
Anyone have more battery charging tips or advice for the new guys on the list?
Tom Gralewicz
Jun 20, 2011, 11:38:58 AM6/20/11
to power-rac...@googlegroups.com
Yes, you can parallel charge lead acid batteries, as long as they are the same age and condition. If one battery is weak or old it can draw all the charging power. In general its hard to get them all to charge evenly - you will be putting most of your charge into the weakest battery. If you use a really big charger on a bunch of small batteries you run the risk of cooking the lowest battery before the charge equalizes.
Lead Acid batteries don't have a high self discharge, its not necessary to keep them on a trickle charger unless you are leaving them for over a year.
A lot depends on the batteries you are using, check the manufacturers sheet and see what the maximum charging current they allow and size your charger for that.
P.S. I was using some Hawker Genisis batteries a few years ago and under "maximum" charging current they said "what ever you can afford" They gave an example of charging a 13AH battery at 200A!
Tom
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