ed

Hi All

I am about to purchase a job lot of NiMH battery packs for a handheld
radio. They are of unknown quality, but are going cheap.

I have 3 radios, but only 1 rapid charger. The batteries are 7.2 v,
and have 3 terminals which connect to the charger, so assume there is
some temperature monitoring.

As I am buying 50 batts, and only need a handful, I want to know how
to quickly sort the good from the bad.

Ideas I have had...

Throw away any batts that are less than 6v.

Charge and then leave for a week, and see what voltage is left/ if
batt can still produce enough current for the radio to transmit
(approx 1 amp)

throw any batts that get excessively warm during charging.

A combination of all the above.

Any help would be appreciated.

Ed
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raveninghorde

I would charge the batteries and leave for an hour. I would then use a
power resistor to load the battery and check the voltage on load. This
will find high impedance cells. I would use something like a 22 ohm 5
Watt or 47 ohm 2.5 Watt resistor.

Recheck the voltage on load after say a week. This checks for
batteries that won't hold their charge.

Finally keep a record of how long the battery works for on the radio
to get an idea of low capacity batteries.