Batteries

[kenputer]

had these given to me, 7 unigy 1,12 avr 100-3et batteries but the voltage showing on them is low,4.04,6.72,8.28,8.53,10.28,10.37,10.47. can anyone tell me if these can be saved?

Thanks

[pyrocasto]

I would say the last three just need a charging, but the 8.28 & 8.53 I dont know. I've brought my 2 at 9 volts to 12, so it's possable. I would guess the other two are dead completely. You could charge them up slowly anyway and see if you have a lower voltage application for them.

[chux0r]

You might try asking again after each one has been on a trickle charger for a few days.

I salvaged the starter battery from a lawn mower recently.  It was reading zero volts, but I charged it up and it starts a lawn mower again.  I'm not sure it can be called "saved" but at least it works well enough for me!

[ghurd]

Usually what I see below 9v for long is done.

Try a trickle charge and then a load.

Might want to try a heavier, normal, charge for a little while to get them up a tad before the trickle charge.  Just to save a little time.

Also, for a normal charge rate, watch the volts for the first few minutes.

If the voltage climbs unreasonably fast, it is shot.

Example: If the 4V battery goes to 14V in 90 seconds with a 3 amp charging current, it is shot.

I have a 12V 7AH at 7V.  I use it for testing controllers.

A 1A charge current gets it to regulation voltage (14V) in about 30 seconds.

Then I can see how the controller is working.

Test it again in a minute off the charger, when the voltage drops to about 9V.

And I thought it was only junk.  

G-

[zap]

Personaly I wouldn't toss em till I'd had them hooked up to a desulfator for a week or so.  kenputer if you haven't been to the desulfator site it might be worth a look.  Some amazing battery come-back stories there.  I think I read where the parts are about $15?  Also they have kits you can purchase.

I've been busy reading, cross referencing, scrounging parts from discarded cpu power supplies, monitors, printers, and the like building my first desulfator.  It was quite frustrating at first.  Built a modified AC circuit 3 times before I realized the circuit was for a PNP and my scrounged mosfet was a NPN.... DOH!  Finally got the sucker humming away working on a couple of old heavily abused maintenance free DieHard wheel chair batteries.... with fingers crossed.  Good luck!

[georgeodjungle]

there all good!!!!

add cadmium sulfate.

ya know "battery additive"

like from jcw

i've seen some at walmart

kind of spendy.