Re-training a battery

[Reveeen]

I just purchased a junk scooter with a "new" battery in it (new, as in less than 6 months old), and the thing (battery) is as dead as a stick. Hooked it to my charger.....nothing. I got to *thinking* (insert smell of wood smoke here). I remembered when the first maintenance free batteries arrived (from Delco), and the replacement rates we had (close to 40%) and what we (as poor underpaid mechanics) did to salvage those "free" batteries for our own use. Combined with a recent exposure to a tool called a "battery conditioner", used to restore battery packs for portable TV station cameras.

I offer this to try, it may work for you (saving you $50), it may not, it does not work in all cases, but the success rate is high enough to give it a try,

A battery uses a chemical reaction to create electricity, sometimes when a battery sits (and slowly discharges over time), it forgets what it is (a battery), and it's purpose in life. So it is up to you, young grasshopper, to re-train it, teaching it it is a battery, and giving it a purpose.

Hook the thing to a trickle charger for a day (24 hours), if you can get it to hold anything (checked with a test light) this may work for you. Hook a tail light bulb to the battery and discharge it (run the bulb) for about 4 hours, repeat the process a couple of times (charge-discharge) changing the length of discharge time (more/less), after about a week of this BS, charging with long slow discharges, it should remember it is a battery.

Good luck!

[Weldangrind]

You should write a book.

So, does the discharge process need to be slow? If I was to trickle charge a battery and then hook a load tester to it, would that be too agressive?

[Reveeen]

The slower the better.......the running light filament of an 1157 bulb is best.

[katoranger]

I am going to try that. I was able to revive my neighbors dirt bike battery with a similar method. It wouldn't take a charge. The automatic charger wouldn't even recognize it.

I told him to hook it to his truck battery via some jumper cables for a few hours. This worked enough to give it enough charge to let the automatic charger recognize that it was a battery and start charging. He was able to use that battery to start his bike for another few months.

I have a few batteries that were piled up for recycle.

Here is another thing I found for my Dad. He bought a dewalt drill on a yard sale for a $1. Battery was dead. Don't know if he tried this.

http://www.instructables.com/id/Revi...with-a-Welder/

[Reveeen]

I would never "hit" a battery with the current/voltage out of a welder, never mind a ni-cad, as they tend to blow up........

BUT:
What I would do is:
Disassemble the battery pack and inspect what is in there. Any corroded/leaking ni-cads have to be replaced (which is beyond the average guy as the leads/interconnects are spot welded, now you can make a spot welder out of an old microwave oven power supply, but that is another story). Once the leaking batteries have been changed out you can try conventional charging, but you might find it won't charge. Go through the cells with your multi-meter checking the cell voltage(s). Any cell not leaking and showing no voltage (or less than .5V) can be "juiced" with 6-12V MOMENTARILY, RESPECTING THE POLARITY. Then try recharging the unit, it should "go".

If you do not respect the polarity, or try to "juice" a leaking/corroded battery, it very well may blow up in your face.

[MICRider]

I've had really good success bringing batteries back from the dark side with my CTek charger from Canadian Tire. Also works as a tender. It even brought back a battery that had been frozen (after it thawed of course). Speaking of batteries, guess it's time for me to bring mine in... I was hoping to get the bike out once more... Bummer.

Cheers,
Stew

[TurboT]

We might have to rename Reveeen, "MacGyver" 8)

Cool info.

[katoranger]

Reveen's method seems alot safer.