How long to charge 9v nimh battery...

[AK]

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]

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]

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]

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

 

[Phil Allison]

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