14.4v batteries
 

Hi

Is there a way to test 14.4v batteries from a drill driver to see what
condition they are in?

I only have a volt/ohm meter.

Dave

"David Lang" wrote in message
k...
Hi

Is there a way to test 14.4v batteries from a drill driver to see what
condition they are in?

I only have a volt/ohm meter.


IMHO the most realistic test for drill batteries is going to be to time how
long the drill or an equivalent load is adequately powered - when they're
knackered, they're knackered

Why can't you just charge em all up then use the drill and chuck out the
ones that don't cut it ?

I imagine measuring the voltage drop under a standard load of apparently
fully-charged batteries would give you an idea ...

You'll need to use a lamp or something as a dummy load ....

"David Lang" wrote in message
k...
Hi

Is there a way to test 14.4v batteries from a drill driver to see what
condition they are in?

I only have a volt/ohm meter.

Dave


if you can open the pack, then check each one with a voltmeter after you
have used the pack , and have left it over night. you will soon spot any
dodgy cells. each should be around 1.2 volts, usually you will find the
worst ones are almost nothing, change those and the pack will be much
better. best solution is just to have it rebuilt by re-cell though !

mrcheerful

In article ,
David Lang wrote:
Is there a way to test 14.4v batteries from a drill driver to see what
condition they are in?

I only have a volt/ohm meter.

You'll get a rough idea by discharging them into a known load - something
like a car 21 watt stop light bulb would be ideal.

If they are Ni-Cads, they're likely to have a capacity of about 1.5
amp/hr, so I'd expect them to run the light at full brightness for about
45 minutes. However, one or more cells always fail first, so if there's a
problem, I'd expect it to be very much less.

High quality cells in good condition should do longer than 45 minutes.

--
*Everybody lies, but it doesn't matter since nobody listens.

Dave Plowman London SW
To e-mail, change noise into sound.

David Lang wrote:
Hi

Is there a way to test 14.4v batteries from a drill driver to see what
condition they are in?

I only have a volt/ohm meter.

Whatever you do, never discharge below 12V.
If you do, one or more cells will be reverse charged, and damaged.
This is also the reason why you shouldn't use a failing battery
till the tool stops.
Swap batteries, and recharge.