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How long to charge 9v nimh battery

Started by AK December 19, 2021
I have a 9V 180 ma  discharged Nimh battery that I am charging at 25ma.

How long will it take to charge?

Thanks,
                 Andy
AK wrote:
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> I have a 9V 180 ma discharged Nimh battery that I am charging at 25ma. > > How long will it take to charge? >
** What you have is a 180 mAh battery: h = hour. You do the math. ...... Phil
Am Sonntag, 19. Dezember 2021, um 05:57:15 Uhr schrieb AK:

> I have a 9V 180 ma discharged Nimh battery that I am charging at > 25ma.
Isn't it 180mAh? milliampere hours and not only milliampere?
> How long will it take to charge?
(180mAh)/(25mA)=7,2h
On Mon, 20 Dec 2021 11:22:04 +0100, Marco Moock <mo01@posteo.de>
wrote:

>Am Sonntag, 19. Dezember 2021, um 05:57:15 Uhr schrieb AK: > >> I have a 9V 180 ma discharged Nimh battery that I am charging at >> 25ma. >Isn't it 180mAh? >milliampere hours and not only milliampere? > >> How long will it take to charge? >(180mAh)/(25mA)=7,2h
For nickel based batteries, you normally add 40-50% to compansate for charging efficiency. -- RoRo
 Robert Roland wrote:
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> For nickel based batteries, you normally add 40-50% to compansate for > charging efficiency. >
** The OP posted a question from some test he had to do. So no such correction factor is needed. For slow charge (8hr) rates - 40% might be OK. But absolutely not for fast charging, or the cells will cook. ..... Phil