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

[mt82]

Just got myself a SkyRC MC3000 charger and I'm very happy with it so far

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]

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]

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]

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.