How long to charge 9v nimh battery

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AK

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Dec 19, 2021, 8:57:17 AM12/19/21
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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?

Thanks,
Andy

Phil Allison

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Dec 19, 2021, 3:34:30 PM12/19/21
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AK wrote:
-------------
> 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

Marco Moock

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Dec 20, 2021, 5:22:09 AM12/20/21
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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

Robert Roland

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Dec 21, 2021, 1:07:25 PM12/21/21
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On Mon, 20 Dec 2021 11:22:04 +0100, Marco Moock <mo...@posteo.de>
wrote:
For nickel based batteries, you normally add 40-50% to compansate for
charging efficiency.
--
RoRo

Phil Allison

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Dec 21, 2021, 6:03:24 PM12/21/21
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Robert Roland wrote:
==============
> 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



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