Keeppower 18650 3200mAh (Black) 2014

DSC_4824

Official specifications:

Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-info

This is the highest capacity cell with 4.35 volt at the current time, but due to the protection the mAh is to low.

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DSC_4825 DSC_4826

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Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-Capacity

The discharge curves does not looke very nice, but that is not due to any problem with the cell, it is because the protection has intefered with the charging.
It can also be seen that the protection trips after some time at 7A.

Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-CapacityTimeHours

Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-CapacityTime

Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-Energy

Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-PowerLoadTime

Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-TripCurrent

Keeppower%2018650%203200mAh%20(Black)%204.35V%202014-Charge

Here it is obvious that one cell stops charging, before the other and probably neither of them is fully charged (The voltage drop when the charge current stops looks to large).



Test with 4.3 volt charging

Reducing the charge voltage slightly gets around the problem with the proction.

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-info

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-Capacity

The difference between 4.3 and 4.35 volt charging is minimal. This time the curves look fine.

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-CapacityTimeHours

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-CapacityTime

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-Energy

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-PowerLoadTime

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-TripCurrent

Keeppower%2018650%203200mAh%20(Black)%204.30V%202014-Charge

Both cells is fully charged here.



Test with 4.2 volt charging

Keeppower%2018650%203200mAh%20(Black)%202014-info

Using a normal 4.2 volt LiIon charger does cost capacity, about 250mAh compared to 4.3 volt.

Keeppower%2018650%203200mAh%20(Black)%202014-Capacity

Keeppower%2018650%203200mAh%20(Black)%202014-CapacityTimeHours

Keeppower%2018650%203200mAh%20(Black)%202014-CapacityTime

Keeppower%2018650%203200mAh%20(Black)%202014-Energy

Keeppower%2018650%203200mAh%20(Black)%202014-PowerLoadTime

Keeppower%2018650%203200mAh%20(Black)%202014-TripCurrent

Keeppower%2018650%203200mAh%20(Black)%202014-Charge



Conclusion

Being based on LG cells, it is good batteries, but with the slightly low protection voltage they do not give the full benefit of the higher voltage.



Notes and links

The batteries was supplied by Keeppower for review.

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries