Battery question

[johndi]

Is there a way to test batteries for cordless tools?
I have an 18v DeWalt set that I bought used. It came with 2 chargers and 3 batteries. Trying to figure out if it's the charger or the battery.

[Robert Adams]

Your can check the voltage with a meter. Most likely the batteries are dead. I never bought used nicad as their usable lifespan is usually only a year or two.

Here are other ways to try charging the batteries but if you're have to ask I don't want your doing it kind of thing.

[thewizzard]

johndi said:

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Is there a way to test batteries for cordless tools?
I have an 18v DeWalt set that I bought used. It came with 2 chargers and 3 batteries. Trying to figure out if it's the charger or the battery.

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So are you saying that neither of the chargers will charge any of the 3 batteries ? Basically, the entire set is dead

I've only ever had one charger fail. It was super cheap Skill 18 volt charger that was always on when plugged in. On the other hand, I have lost numerous NiCd packs. They simply just " go bad " and wont take or hold a charge.

I'm leaning heavily toward bad batteries but you will need a simple volt meter to diagnose the batteries and chargers.

[LarryC]

There are ways to test batteries, but honestly it's gonna cost more to buy the tools for testing than a new set of batteries. As mentioned by Thewizzard, if both chargers fail to charge one of the three batteries then chances are the batteries are done. Buy one new battery to confirm if you feel it's worth while. Personally, I never buy used batteries since there is usually a reason they're being sold.

[johndi]

Thanks for the replies.
I figured it was the batteries but am ignorant of all things electrical and wondered if there was a simple way to check them.
One of the three holds a charge fine, but with 2 chargers and 3 batteries, it's like a shell game trying to figure out.

Time to buy new. Thanks

[thewizzard]

With one good battery it will be simple to figure this out.

Drain the battery and see if charger - A works. If it does, drain the battery and see if charger -B works. This will quickly tell you if the chargers work.

After you know which charger(s) work testing the other 2 batteries is trivial.

[arthropod98]

i've got some older 18V nicad tools and the batteries wouldn't hold a charge anymore. i found decently priced new batteries at cpo outlets -- just a fyi.

[kurt18947]

It's possible to rebuild battery packs with cells better than new. Whether it's worth doing is another question. I had a couple P-C battery packs rebuilt by MTO battery in York, PA. some years ago and the rebuilt packs had more runtime than when they were new. YMMV I expect.

http://www.mtobattery.com/product-catego...-services/

[DogwoodTales]

Is this the battery you need?
18v DeWalt

I recently bought a pair of 14v batteries via Amazon for my Milwaukee drill. So far I'm satisfied with my purchase. The batteries seem to take and hold a charge well.

I did rebuild battery packs myself for this same drill.
I don't know if it was the batteries I got, or if I may have overheated them while soldering the tabs on the batteries together, but they didn't last long and were never up to par with the manufactured batteries, even though they were supposed to have more Amh than the manufactured batteries I had. In my experience rebuilding wasn't worth the time and money.

With some alligator clips and light wire you can hook up the +/- of a 9v battery to the respective +/- on your drill batteries for about 10 seconds. (Basically giving the otherwise dead battery a "jump".) Then immediately put the battery on the charger. If it starts charging you will get some more useful life out of the battery. I did this with some of my batteries for that Milwaukee drill. It works, if the battery will take the jump, but the battery will not have the same Amh life and the power will be a little less, even with a full charge.

[messmaker]

I have been told that ni-cad should always be above the listed voltage. A fully charged 18 volt battery should read maybe 18.5. Less than 18 and your battery is shot.