I've just got a new 2500 mah NIMH battery. Can I charge it with a NICD charger? Can I used my standard Futaba or JR charger that is a NICD charge to charge a NIMH battery? I beleive I can, but I wanna check with you guys frist...

carlyle

A wall wart charger from a radio system puts out 50-60 mA, not enough to properly charge any battery that size. At a C/10 (overnight) rate, you need 250mA current at 1.4 volts per cell. So you need a heftier charger to ever get the 2500mAh battery charged. Here's a pretty fair reference:

http://www.powerstream.com/NiMH.htm

And, as far as fast chargers, only use one that is rated for NiMH. NiCd batteries charge differently than NiMH, and the charger (if it's intended only for NiCd) may not read the peak charge properly, and ruin the battery. Make sure your fast charger is set for NiMH before using it on your new battery! And, you need to slow charge the battery for the first time, or you run a HIGH risk of ruining it. Never fast charge a battery for the first time! Do yourself a favor, and buy a nice charger/cycler such as the triton or such--you'll be thankful for that purchase for as long as you're in the hobby!

Thanks guys.

I guess I'm just trying to put somewhat of a limit on the amount of money I have to spend... I guess that just isn't possible, is it!

Anyways, thanks for your help,

Carlyle

Carlyl, yes you can use your old wall wart to charge that battery, it will just take a very long time. At 50 ma, your 2500 mah battery will require at least 72 hours to fully charge; and yes it will eventually reach full charge as long as the input current exceed the self discharge rate. The good thing about using this slow a charge rate is that, should you forget and leave the charge on for a week, you won't damage the battery.

It's just that .1 C (or, 250 mA for a battery of that size) is the accepted rate of slow charging. HOwever, Rodney is correct!

I just baught a new charger today. I'm getting it from Great Hobbies. Can't remember exactly what kind it is, but it is completly programable, etc. What should I do my inital charge at? 250ma? 100ma?

Carlyle

set it up for 250 (or as close as you can but not more--if you have the option of 240 or 270, always go for the lower value. It'll charge a bit slower but it is also safer) and you also need to set it for either 4.8v (4 cell) or 6v (5 cell), whichever you have. The usual charging rate is 1/10th of the capacity.