Eneloop AA BK-3MCCE 1900mAh (White) 2019



Official specifications:

• Nominal voltage: 1.2V
• Minimum capacity: 1900mAh
• Low self discharge: 70% capacity left after 10 years
• Cycle life: 2100 cycles.

Maximum temperature raise at different discharge currents: 1A:+1,5°C, 2A:+3,6°C, 3A:+5,9°C, 5A:+11,3°C, 7A:+16,2°C, 10A:+21,4°C
This is a retest of the standard eneloop (Previous test is from 2016).











Fairly standard NiMH discharge curves, the capacity is not record breaking for Eneloops, but they do not self discharge and they last a long time (Except if they are over discharged).















Turn a 1A load on/off makes it possible to calculate the internal resistance, here I have done it for a lot of times during a full discharge.
The reason for two curves is that one is calculate from voltage drop when switching load on (L->H), the other from voltage increase when switching load off (H->L).



The eneloop is supposed to work at -20°C and it does, but with reduced capacity and voltage.



The 1A discharge curve looks very similar to the 0.5A curve.
Note: The temperature sensor is not on the battery.



It is usual said that NiMH batteries must be loaded to read capacity, here I have shown remaning capacity in percent based on time after a 1A load is removed. I can see from my data that one hour is not long enough for the battery to recover fully, i.e. the voltage would probably be even worse for estimating capacity after a few hours more rest.



Conclusion

The performance of the eneloop is good and it also works when it is cold.



Notes and links

I am replacing my NiMH charger test batteries, they are from 2016 and some of them has a fairly high internal resistance. Some of the bad chargers I have tested have probably increased the deterioration rate of them.

The extra data in this review is not something I will do in other reviews, except maybe a few IR curves may show up.

How is the test done and how to read the charts
Compare to other AA/AAA batteries: Alkaline/NiMH/Lithium