Safe to charge poentially "overrated" NiMH at 0.1C for 16h?

mt82

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Joined
Mar 12, 2021
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Just got myself a SkyRC MC3000 charger and I'm very happy with it so far :D

I have some old cells I would like to try with the breakin charge. I have some ActiveEnergy cells from Lidl that are rated at 2100mah, and which only seems to perform at 1600mah. So the MC3000 charges them at 0.1C for 16h. I entered the capacity at 2100mah but I'm now wondering if that's safe if the battery really is only at 1600mah? Because in that case, I'm suddenly charging a 0.13C instead of 0.1C. And while that may not seem like much, the whole concept of break-in is a deliberate overcharge (due to the 16h) at a level the battery can handle without exploding... so I'm wondering if this could cause problems. Or maybe the rate is still so low it's not a concern?
 

ChrisGarrett

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Feb 2, 2012
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5,726
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Miami, Florida
Save them for low drain apps, since you'll never get that capacity back.

You have a great charger so start over with fresh NiMH batteries from either Fujitsu, or Eneloops and keep charging ahead.

Chris
 

sbj

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Feb 19, 2017
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At 0.1C = 210mA charge rate, the heating of the cell in the event of overcharging is very limited with approx. 0.3Watt. They have been able to withstand this for a while. But not unlimited either.
Anyway, I wonder who applied that to the NiMh batteries with the 16 hour charging time?? :devil:
I know that this is recommended very often now at 0.1C.
- In the past, 14 hours were always recommended for NiCad batteries, which in my opinion is also completely sufficient for the NiMh.
 

NiOOH

Enlightened
Joined
Oct 14, 2006
Messages
431
If you want to do a break in charge (0.1 C for 14-16 h) it is best to chose charging current based on the real capacity of the cells, and not on the nameplate capacity.
IMO, modern NiMH cells do not need break in, I stopped doing it on new Eneloops years ago. Just charge them on my MC3000 at 0.5 C and 0dV from the first cycle on.
 
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