I purchased a Supernova 250S charger for Ni-Cad and Ni-MH batteries. I know almost next to nothing about batteries. I am sitting here with an eight pack (8 AA Ni-MH batteries, each has a rating of 2100mAh on it.)

The xcharging instructions give a sample of a battery pack of 3000mAh that is composed of 9 cells. Now does the sample mean that the 9 cells equal a pack rating of 3000 mAh or is easch battery 3000 mAh for a total pack value of 27000 mAh?

Back to what I don't know, which is almost everything. Are my 8 AA batteries, each rated at 2100 mAh, is the pack rate then 16800 mAh or is my pack rate 2100 mAh? The charger instructions state that the charge rate should be 1/10 the pack rate.

What MA should this paxck be charged at? And can someone tell me how this works-math wise? I sure would appreciate the help. Also, what voltage should they be charged at and what voltage should be used to discharge?

Thank again. Confused..

Back to what I don't know, which is almost everything. Are my 8 AA batteries, each rated at 2100 mAh, is the pack rate then 16800 mAh or is my pack rate 2100 mAh? The charger instructions state that the charge rate should be 1/10 the pack rate.


Your pack is rated at 2100mAh. The cells are in series, one next to another the voltage of each individual cell adds, but the current or mAh (milli 1/1000 - A amp - h - hour) is only as good as the smallest cell is capable of supplying. In your case because all the cells use the same mAh rating that is 2100 mA or 2.1 amps. So your initial charge rate to form the pack is .21 amps.

Better?
John

EDIT - > After the pack is "formed" (initially charged) and discharged. You can then fast charge the pack at 1C or 2.1 amps. I never charge above 2C and then only if I have too.

joe , you have bought a corvette and you dont have a drivers license. this charger has a notoriuosly poor manual.hopefully someone who has this charger can go thru the progamming sequence for an 8 cell pack. try too use the parameters that are in your manual as a start. be skeptical of information that you are given about how somebody else does it on the charger that they are using. i notice that if you are charging a ni-cad simply go to automatic mode and connect battery. the unit will auto detect number of cells ,charge rate, discharge rate.try that first.

Thanks to both of you gentlemen. I guess it's plain that I'm pretty weak in my understanding on this subject. I am doing my best to get an educated. Any and all additional advise or instruction will be appreciated and welcome. And thank you again.

Laryboy,
"be skeptical of information that you are given about how somebody else does it on the charger that they are using."

Information I gave was just on forming a battery using C/10 rate and a 1C rate for rapid charge. About as safe and general information as you can get. I don't post what I don't know. It is the battery that is charged. It doesn't care who manufactures the charger.

John

J Norton is correct, for best results, do as he said. You might want to check out www.rcbatteryclinic.com for some good informative reading.

norton, i am refering to the programming of this charger. every parameter is a variable to be set by the user. you have to look carefully to see if you are required to input current as 100ma or.1 amps, for instance or perhaps 1c