Multimeter settings for battery testing...

[Deluks]

I'm following this guide on youtube, in a rather amateurish fashion.

Just bought a cheapo digital multimeter (same as this one) but electronics has never been my strong point and I was wondering which of the myriad of settings it needs switching to in order to test cordless drill batteries. Namely sub C's from a Bosch 18v pack.
I'm guessing I should have put the battery pack on charge before I took it apart as I'll be testing a run down battery. Duh!

 

[neds]

Don't you charge them up then take the voltage, the one not showing any could be the duffer. Stick it on one of the DCV settings, then you just move the decimal to a more readable setting.

 

[Monkeh]

Put it on DC 20V.

 

[Burnerman]

Its always best to test a battery under load......even a dud one may give a high voltage reading, but under the slightest load will drop a good few volts.
John

 

[Deluks]

Its always best to test a battery under load......even a dud one may give a high voltage reading, but under the slightest load will drop a good few volts.
John

Don't know how I'll load these for testing, they are all mostly still soldered up in the pack.
Using DCV 20 I'm getting reading from almost every one, ranging from 0.9x to 1.1x I assume that means they are still servicable?

One was a flatline/0.01 and another was about 0.83, these also have a little corrosion around the + end (acid leak?) I'll replace those two and see if that sorts it out. This battery has been duff and sat in the garage for the past 2 years, If I can sort it for the sake of a fiver and a bit of soldering I'll be a happy bunny.

 

[Stivino]

I don't think it would be a good idea to put two good batteries amonst ten (I'm assuming there are 12 in total) other not so good ones. If two are dickie, I think the others won't be far behind.

 

[Deluks]

There's about 14, I don't think the cost of that many new ones justifies the cost. I'm just hoping I can get some extended life from a duff battery pack. Only duff for the sake of 2 batteries


There's another duffer, much older but if I can cadge a couple of good batts from it then I repair this one for free


I've also got a third 2.6ah NiMh which has had very little use but only lasts about 10 minutes. I'm sure there are plenty of decent cells in that one still. Would be a waste to chuck it.