NiMh Charging

[Rudd]

This might feel like you are talking to a man from the 1980's but I'm after some NiMh basic charging advice.  I have a 9.6V Traxxas 5000mah series 5 battery. I'm using a multi charger and it asking how much current is required starting from 1.0A. I'm more used to charing Lipo - should i go for 5.0A - or does it even matter?

 

Thanks!

[Fly In My Soup]

It's a trade off....how much time it will take to charge Vs. how well it charges

 

Increase the ah and it will charge quicker, but won't maximize the battery's capabilities

 

Decreasing it to a lower ah charge rate will charge your batteries cells better, but takes longer.

 

A simple way to work out how long it will take to charge....

 

I used to charge NiMH over 3000mah at 2a, and below 3000mah capacity at 1a.

 

Just set it to 2a and endure the long wait! It will stop charging a 7.2v nimh battery at around 8.2-8.4v, and a 9.6v battery at around 11.6-11.8v (120%)

 

Example;

 

a battery with a capacity of 1600 mAh will require about 4 hours to be fully charged by a charger with a charge rate of 500 mA. (1600 mAh/500 mA x120%).

 

Just ensure not to trickle charge a NiMH at a really low rate, say 0.1-0.7a

Edited November 13, 2017 by Fly In My Soup

[Fly In My Soup]

P.s 

 

as NiMH batteries are extremely resilient to being stored at full charge, I used to charge until full the night before ( on 2a ) then let them rest overnight, then give them a quick charge on 4a in the morning before heading out...this is known as 'packing' the cells

[Rudd]

brilliant - thanks. You should 'charge' for advice!

[Tear101]

I run a traxxas Nimh in my boys car and as has been said above I go for full charge then let it rest and then top it up before you go out. I thought I had got a duff one because it wasn't lasting very long and loosing punch real quick, but charging it like this has really sorted it out.

[Z750jay]

If I have time I charge my 4.6amp NiMh’s at 0.1amp - takes a couple of days but the battery gains as close to full charge as you will get. In a rush then its 1amp charge rate.


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[XV Pilot]

On 13/11/2017 at 23:01, Fly In My Soup said:

P.s 

 

as NiMH batteries are extremely resilient to being stored at full charge, I used to charge until full the night before ( on 2a ) then let them rest overnight, then give them a quick charge on 4a in the morning before heading out...this is known as 'packing' the cells

 

This is good advice. Unlike old-school NiCad batteries that were best stored discharged, NiMH are not only resilient to being stored charged - they insist on it! Storing them discharged can actually damage them - I found this out the hard way back in the day when transitioning from NiCad to NiMH, rendering an almost-new NiMH pack useless by treating it like a NiCad.

[Fly In My Soup]

8 hours ago, Z750jay said:

If I have time I charge my 4.6amp NiMh’s at 0.1amp - takes a couple of days but the battery gains as close to full charge as you will get. In a rush then its 1amp charge rate.


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On 14/11/2017 at 08:51, Rudd said:

brilliant - thanks. You should 'charge' for advice!

 

See here dudes