batteries reading 27 volts?

[mike-on-da-bike]

i have 2x 12 volt 10ah lead acid batteries wired in series to make up 24 volts,i charge these with the standard currie 24 volt charger but when i read the pack it shows up as 27 volts on my multimeter,is this the normal reading for a setup like this or are the batteries getting overcharged and should i go get a better charger?the charger i have says on it output 24 volts 1800ma

[karma]

its normal. i have 2 x 24volt packs that read 53volts no load. and when its off the charger drops to 50volt. your charger should
turn off when the charging cycle is finished.if not you could cook the batterys.

do thay get really hot?

[mike-on-da-bike]

ok thanks so it nothing to worry about then i was thinking off getting an auto charger that will turn itself off soon,i dont think my batteries get hot but that currie charger gets toasty if left on overnight.ps i have noticed if i leave batteries on charger all night they take me alot further than if i just charge for a few hours but in both cases the light on charger is green and say the job is done,so i may have to read up some more about charging these batteries in series,maybe it is taking all night for the second battery to charge.

[Abneycat]

The higher-than-rated voltage is perfectly normal for just about any battery chemistry. I'm not entirely sure, but I believe the rating batteries are given is based on the average between total charge and total (failure rate) drain. For my 37v battery, it was 42v when fully charged, and for the 48v battery it was about 54.

[electrogreen]

I have 3 36V NiCad batteries. I've never actually seem them read 36 volts. Currently the two fully charged read 41V and the one I used today reads 37V.

[meb]

its normal. i have 2 x 24volt packs that read 53volts no load. and when its off the charger drops to 50volt. your charger should
turn off when the charging cycle is finished.if not you could cook the batterys.

do thay get really hot?


A single 12V battery is supposed to transiently be at 13.2 v upon charging completion and then drop to 12.6 v, so the 53 and and 50 make sense.

24V bike SLA smart chargers charge till 27.6v is reached, but I have not been given any explanation on why-seems as if 27.6 being more than 13.2 x 2 would overcharge the battery. Anyone have any explanation on why 27.6V instead of 26.4V? Anyone know why that voltage doesn't damage the battery?

The 27 volts the OP has seems slightly high-would expect it to drop to 26.4V immediately, then be at 25.2 the next day if not ridden. But given the 27.6 V charger shutoff, 27 V on the battery doesn't seem implausible.

Anyone know why the battery would stay at 27V?

[mike-on-da-bike]

i did some more checking and the battery maker says to charge a their single 12 volt lead acid battery at no mre than 14-4 volts and the charge rate should be no more than a tenth of the amp hour rating and no more than 3 amps for a 12 volt 10 ah hour one.i seen that these deep cycle charger do a cyclic charge which is a bit higher than normal lead acid charger,they do a constant current bulk charge.yes and that higher voltage reading is very normal.