I have two battery packs for my 18v Dewalt drill and neither will take a charge. Is there a way to revive them so they will charge up?
You can try zapping the battery packs with a welder per the referenced URL. I've never done that personally but I've had quite good success zapping individual Ni-Cd batteries with an auto battery charger and it's worth a try. You definitely need a higher current and/or voltage source to successfully zap a battery pack with its array of series and parallel connected cells. If that doesn't work, if you're handy you can try rebuilding the battery pack by disassembling it and testing/replacing the bad individual Ni-Cd sub-C cells. There are several good sources online for detailed info on how to do that. I also happen to own a DeWalt cordless drill with 2 battery packs that are slowly going bad and that's what I plan to do when they finally fail. Replacement battery packs are ridiculously overpriced and are only a last resort. Good luck!
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I've tried using the freezing and heating method, but it did not work. Here's a method of bringing them back to life by zapping those shorted crystal dendrites away with too much current and/or voltage. You can use a welder as a power source. You could also use a car battery, a DC powersupply, or almost anything with some voltage. Make sure to wear eye protection, match negative with negative and positive with positive, and zap it for 1 - 2 seconds a couple of times and it should be good as new. I 'd hook up the negative side to the battery first. Then touch the positive to the positive side. You want to see some sparks - it is normal and not to worry. If you're not sure which is positive or negative on the battery, you can use a volt meter - use the meter also to measure the almost immediate result before and after the battery has been zapped. Repeat the process if the battery is still not holding charge, but I can assure you that you will see a big difference almost right away. The battery companies do not want us to know about it so they can continue to rip us off. Good Luck!
No simple way as rechargeable batteries have a limited number o fcharge and discharge cycle, around 200 to 500. After that, it's dead and will need a new one.
