Tools, Sharpening and Power Machinery - testing rechargeable batteries

anyone know a ohm/voltmeter test for rechargeable batteries. Specifically, I have several 14.4 volt Black and Decker Firestorm batteries and one or more of them is probably bad and blows out the charger. I do not know which ones may be bad, and they are dead so you cannot tell which ones did not charge? Anybody know of a test to determine GOOD ones prior to charging? Known problem with these batteries blowing chargers from what I hear.

Have you opened up the 14.4 volt battery to expose the 1.2 volt batteries inside, and are you wanting to test them?

I have opened the dead 14.4 case and looked for broken wires and the like. Black and Decker says a bad 14.4 battery is causing the charger to blow out and to test the 14.4 batteries to find the bad battery. If that means opening and testing the individual ni-cad cells fine except the batteries are dead and cannot be charged without blowing up a charger??

First, I want to say that about a month or so ago I spent a lot of time taking apart my two Craftsman 14.4 volt ni-cad batteries and testing the individual 1.2 volt batteries inside only to decide that the cost and time involved to repair them wasn't worth it. I found a deal at Home Depot for Ryobi 18 volt drill, circular saw, light and sander, with two batteries for $100.

Now, if what you are trying to do is test the batteries inside, I did this by touching the tips of the voltmeter to the ends of each battery. I got 0 volts for most cells; but some had voltage, I think about 1 volt. So I figured the 0 volt ones were bad. You could also test by connecting one end of the voltmeter to the first cell, then moving the other probe to each battery successively to see if the voltage keeps increasing (the batteries are in series so the voltage should increase).

Not sure any of this will help you but good luck.

what I am trying to determine is what battery not to plug into the charger that keeps blowing chargers so I can trash that battery and protect my charger. If I can determine continuity or lack of it with a ohm meter without taking the packs apart fine?

Okay, my understanding is you have two batteries, and when one of them is plugged into your battery charger it destroys the charger. Is that right?

I don't think you can test a battery for continuity with an ohmmeter.

The first thing I would do is check the voltage of each battery. If one shows some voltage and the other doesn't, the I'd suspect the one with no voltage is the problem battery.

The only reason I can think of for a battery to destroy a battery charger is that the battery is short circuited. I'd take the case off each 14.4 volt battery (assuming they are held together by screws) and look for burned areas inside. If I didn't see any, I'd then check voltage from a starting point to each of the 1.2 volt batteries looking for a point where the voltage drops back to zero (meaning the short is there).

Good luck.

Thanks I will give this a try.