Hot cells while charging NiMH

[NoisyGriff]

Hi guys,

Bit of a novice question, I fear. I've just got a charger for my Tx (9.6v) and Rx packs. Having wired it all together, I charged my Tx pack and watched its progress with a voltmeter to see what's going on.

The pack is made ip of 2500mAh NiMH cells, so I charged it at about 2400mAh. The pack got hot hot hot. The best way to describe the temperature was that it was too hot to squeeze for more than about 10 seconds. The cells reached this temperature towards the end of their charge.

I let the charge run its course, because I was happy to watch the volts. The voltage (while charging, got up to 15.42 volts and then started to drop, at which point the charger clicked down to trickle charging.

So the charge seems to have worked a treat, but I was wondering if you guys had any experience of how hot the cells should get during a charge...

Sorry about the rambling post. :?:

[tnreefguy]

I had the same problem with my NiMh getting hot when I tried to charge them at 1C or there capacity. Turn your charge down to about 1.5 to 2 amps and you will be ok. Thats what I did. It takes a little longer to charge but with no heat issues.

[NoisyGriff]

That sounds like the most sensible option. Last thing I need to to end up with my transmitter sitting in the bottom of its own crater, while I wander round the field picking up chunks of what used to be the flight box/heli/back of the car etc.

Thanks for the advice.