Cordless Screwdriver, How to Test: Dead Battery or Charger?

[Neal]

I'm hoping someone here can advise me. I have a Milwaukee Cordless Screwdriver #6539-1. It takes a smallish rechargable battery: Milwaukee 2-4 Volt Battery Cat No. 48-11-0100. When the battery is in the charger, the red charger status LED lights dimly, but the battery has ZERO juice when removed. How can I test to find wether the problem is with the battery or the battery charger? I do not have a spare battery to confirm. I do have a decent multimeter , jI'm ust not sure how to go about the diagnostic testing. Thanks a bunch for any guidance. Cheers, Neal

[Edwin Pawlowski]

Put the lead on to the batter and take a reading. Put the leads on the charger contacts and take a reading.

If you have a problem doing that, put the meter for sale on eBay.

[Nick Hull]

It might be a dendrite problem in the NiCads. Read the battery voltage, flash with your car's 12 volt battery and read the voltage again. If it came up to normal then try charging normally in the charger.

[Jeff Wisnia]

Now, what I'd recommend doing is to use whatever bits of wire and bent paperclips are required to put the meter (set on its current mode)in series with the battery and its charger and see how much current the charger is delivering to the battery when they're connected that way.

Start out on the highest current range of the multimeter and work your way down to an on-scale reading.

If the measured charging current is reasonable, say numerically in the range of 1/4 to 1/10 of the battery's amp hour rating, and you leave it conected that way for an hour without the battery charging up enough to make the tool do its thing, then it's the battery's fault.

If you measure zero charging current, then it's likely the charger, or the battery is completely open circuited, which is highly unlikely.

Jeff

[Neal]

Ed, Thanks for the advice. With a warm battery fresh out of the charger, I get a reading on it...of pretty much nothing. One the other hand, when I put the probes on the charger contacts, I get a reading of about 1.5V. I'm not sure what the charger should be reading: so, is this a dead charger, or a dead battery, or possibly both? Meter's fine ;-) Thanks.

On Mon, 10 Oct 2005 23:39:37 -0400, Edwin Pawlowski wrote (in article ):

[Stormin Mormon]

Take a good look at the square black plug. Usually says the output voltage. I'd guess 4 or 5 volts. You can usually read the terminals where the charge stand touches the cordless device. The terminals should be near to the voltage that's listed on the plug.

I did a quick Froogle search, these gadgets start at about $100, so it's worth some trouble shooting.