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One of the batteries on my Porter Cable 19.2v drill wouldn't hold a charge anymore. Straight off the charger it wouldn't even drive a single screw. Checked around for a replacement and they cost anywhere from $50 to $80 even on eBay. I decided to Google ni-cad repair and found this.

What have I got to lose? I decided to try the "fix" and much to my amazement; it worked. I don't have a welder so I used my automobile battery charger which seems to have put out enough power. After zapping the battery, I charged it up and started driving screws.

The end result is no out of pocket for a new battery and a free fix. Now this is my kind tip.

Caution: This ONLY works with ni-cads and NOT ni-mh or lithium ion so make sure you check your battery type.

[quote=tdubnik}

What have I got to lose?


WARNING:
If you get killed by a poisonous explosion it means you did something wrong.
Electrocution is a real possibility also.
Ask your parents how to not electrocute yourself with a welder.


You cant say they didn't warn you!:D

I found a procedure once a few years back to fix an old Sony handycam (camcorder) battery that refused to take a charge. Some of the Sony batteries are too smart and have logic in them that makes a determination if a charge is needed. Anyway, I found that if I put a large ceramic resistor (~10ohms, 15 watts), I could drain the battery sufficiently to fool the logic into taking a charge. Works great and I can still use that dumb battery..

Tried it with the battery charger, but the charger circuitry didn't allow a spark.

Tried it with a old marine battery and the drill spun briefly.

Got out the big guns ......Hooked jumper cables to the conversion van, started it up, clamped some insulated copper wire to the cables. Got a nice bright spark on the battery terminal. Drill spun, but slowed down.

Dropped the battery in the charger. Went from "soft start" to "rapid charge" in about 15 seconds. Charge complete in a hour. Hadn't done that in over a year.

My 20 year old Craftsman Industrial 3/8 is now spinning very nicely.

Sure wish I had the other 2 batteries that I recycled a few years back.

I now have a clients 2 12 volts to do ( she paid $70 for the B&D 6 years ago; if this works she will be a happy camper ), and a neighbor has 2 19.2v and 1 18 v. Should be interesting to see if the 12v zap will be enough for the 19.2 and 18v batteries. I'm guessing it's the initial amperage that is cleaning up them up. Will report on the next experiment.

Tdubnik........with the money this saved me, I owe you a beer. Thanks!!!

That's an old and surprisingly effective trick. Comes from lead acid batteries. An old trick for reviving your dead truck battery is to jumper it to a/c for a few seconds. 110 or 220, either will work.

foxtrapper wrote:That's an old and surprisingly effective trick. Comes from lead acid batteries. An old trick for reviving your dead truck battery is to jumper it to a/c for a few seconds. 110 or 220, either will work.

Not sure THIS is a good idea! This is new! Someone explain to me HOW/WHY it would work!

Was using a B&D 14v Firestorm in a hedge trimmer. Trimmed one side of 92' without problem. After recharge, would only trim 6' on the other side. Zapped it with power from the conversion van. Then recharged. Trimmed the last 24' with no problem and there was still power left.

The 12v on my drill has held the charge for 2 days now.

Saw a thread for lead acid batteries that used a Epson salt/distilled water solution to clean the plates with. Various methods----leave it in and recharge for 3-4 nights, keep rinsing until the solution is clear, etc. Not sure I'm too wild about draining the acid out of the battery. Would need some glass containers. I can see it now.........."Honey, where's the 9x13 pyrex pan?".

JPG40504 wrote:Not sure THIS is a good idea! This is new! Someone explain to me HOW/WHY it would work!

Lead acid batteries (and others) build up contaminants on their plates, and sedement in the solution around them, particularly under the plates. The battery will tend to work ok until the build up or sediment finally touches things it shouldn't, shorting the battery out internally.

Using a welder or a/c power is simply an act of violence. You are blasting the battery internally with the large current, literally knocking things off the plates, and stirring up the sediment below the plates.

Looks like the radio control car guys have been doing this for a while to get more performance out a battery during a race. See the link below

http://www.buchmann.ca/Chap10-page4.asp

Also hit the Home button. There is a wealth of information here on how these batteries work.

I don't know why it works but I do know that it seems to have fixed my battery. Since I have zapped mine, I have used it and then left it for days and then used it again. I can tell NO difference in performance between it and the one that has not required zapping yet. Saved me about $60 on that one.