Is this the "ideal" NiCad charger, or is it crude?

[Damo666]

Hi Fellas,

I've built this circuit to charge my old 8.4V 7 Cell 80mAH NiCad batteries; http://sv1bsx.50webs.com/charger/charger.html

For the resistor I've used a total of 160 Ohm for a 8mA charging current. I'm using a variable PSU (0-18V 30A) set at 13.5V to supply the circuit.

What I want to know is, is this circuit ideal for NiCad longevity, am I using the right Voltage, is it crude, and are there any better ways to charge my now unobtainable NiCad's for a long lasting service, or is this circuit just the ticket?

I want to look after the pictured batteries the best I can, as they are 20Yrs old and now unobtainable. They are used as the power source for some old radio equipment.

Cheers.

All the best,

Damian

[audioguru]

Eveready charged their Ni-Cad battery at 1/20C for 2 Years and the battery performed almost like new.

I worked with a wireless tele- conference microphone that used AA Ni-Cad cells. ALL of them ended up shorted after a few years after being continuously trickle-charged.

ALL the Ni-Cad cells I had for a few years also ended up shorted.

Most of my AA Ni-MH cells have low capacity and low maximum current. They are up to 10 years old.
Energizer is going to send me coupons for free replacements. Excellent customer service. 

[Kevin Weddle]

Experimental battery chargers are good for the hobbyist, but they fall much short in technological development and will not serve for practical usefulness. Only the correct charger is designed for charging the 8.4v NiCad. But it's fine if you want to power some small circuit.