Chuck Harris wrote:

NiMH cells don't like being trickle charged. If you want to
charge them at a "trickle" charge rate you need to use a smart
charger that will cut off the current after they have reached
full charge.


Hi, Chuck -
Yes, I agree that one must be careful about using a NiCad charger
with a NiMH battery, the NiMH can be in danger of overcharging.

In the Racal receiver memory protect circuit,
there is a silicon diode in series with a 270 Ohm resistor
from the 5V supply to the 2.4V battery, which means about 7 mA
trickle charge rate. I looked at the Varta site, for a 110 mA-H
button cell (2/3 capacity of the 150 mA-H Racal battery suggestion),
they say either 11 mA continuous trickle or 22mA for 1 year
would be overcharging. So, there should be no problem in the Racal.

73,
Ed Knobloch