Battery Charger

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Pause please

Dude 88,
Let me see if I got this straight.

Your trying to charge a SLA battery.
Ran it over night on a 2 amp charger, and it diden't work.

If Ive got that right, good chance the battery is dead. Sorry to report that they don't get better.

Used to happen to us all the time in the chemical weapons radio business. We used SLA cells for the base station battery pack and the customers almost never took care of them. So after two or three years of running and charging, the cell packs burned out and were never coming back.

They 'sulphate' over time. When that happens, they won't take a charge, or if they do, it self discharges quick.

The best thing to do is take the dud cell pack and have it recycled with dead car batteries, and go buy your self a fresh one.

There is a shelf life and a service life, and neither of them get better on batteries.

Good luck there
Jack Crow in Kuwait
 
hey , thanks for the info. The cell I have I pulled from a ups, and the battery was still very much good. Plenty of amperage. I let it sit for about a month or so before using it again, and it was totally dead. I aslo have another one that has some power left in it, enough to run a small motor slowley, think it will charge?
 
it doesnt draw a whole bunch of current, the voltage increases ( I got the dead one to go up to 11.6v from 5v) but no amperage out of the battery meaning its still dead.

I threw together a charger running off of a 12vac trafo, into a LM7815 regulator, resistor and diode. Out put is about 14.5v @ 1 amp, although the batt wont draw that much from it.
 
Letting the battery sit for a month with no charge applied is the same as draining the charge off with a load, just slower. The self-discharge rate of LA batteries is pretty high and they don't recover well from deep discharges, as you have discovered.

If it won't take a charge from a "normal" level of current, there are safety reasons why you SHOULD NOT try cranking up the charge current. You are liable to boil the stuff inside the battery and if you're very lucky it won't boil-over or even explode and spray nastiness everywhere. If you have to try it, do it outdoors, with the battery sitting at the bottom of a deep, oncovered plastic bucket so that if it does blow/spew it won't mess up anything of value.

It is probably time to go buy a new battery.

I_F
 
Dude88,
These guys have a better grip on this than I do.

So to quote Dr. McCoy "It's dead Jim".

Give it a nice funeral and find some new ones.

Once place Ive found cheap SLA's is in auto parts stores. Seems some are used for small trailers. Not too expensive.

As for the LiOns, they are real fussy about recharging, and if you don't give them exactly what they want, your playing with fire. There is way too much energy in that small package to risk a failure.

I won't even consider playing with Li cells at home, and dident' like them much at work.

Please don't mis understand, the work great, but if they are mistreated even slightly, it's a mess and a dangerous one.

Hope this helps.
Jack Crow in Kuwait
 
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