Test/Review of Keeppower 16650 2500mAh (Black) 2015

Keeppower 16650 2500mAh (Black) 2015



Official specifications:

  • Capacity min.: 2400mAh
  • Capacity typ.: 2500mAh
  • Nominal voltage: 3.70V
  • Charge voltage: 4.35+/-0.05V
  • Standard discharge cut-off voltage: 3.00V
  • Standard charge current: 1000mA
  • Charge termination current: 50mA
  • Standard discharge current: 2400mA
  • Max. continuous discharge current: 6A




This is a slimline version of the xx650 battery, it can usual replace two CR123 cells. It has a lower voltage, but more capacity.











The discharge curves looks very good, but the capacity is rather low. The low capacity was expected, the problem is the protection circuit, it terminates before the battery is full!













Look at the voltage drop when charging terminates, it is way to large because of the protection circuit.



Charging with 4.30 volt



Lets try a slightly lower charge voltage.



The batteries has more capacity at this voltage and the discharge curves looks good.













No big drop when charging terminates, this time the protection did not trigger.



Charging with 4.20 volt



What about using a normal LiIon charger?



It is about 200mAh less than 4.30V charging.















Conclusion

It would have been nice with a protection circuit for 4.35V, but even with the capacity loss the battery is a good and a very good substitute for CR123 in lights that can handle the lower 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
Compare to 18650 and other batteries

Thanks hkj, a more interesting battery review than usual! :slight_smile:

I would say a more interesting battery than usual.

All 4.35V batteries gets the longer review, that takes about 3 weeks to test.

Thanks HKJ. Seems a good alternative for people who own a non-metallic (polycarbonate or other: Surefire or Streamlight) flashlight and are unable to increase the bore of the tube to make room for a 18650 battery.

Looks a good candidate for the Quark Pro QT2L! Thanks HKJ

Are the 4.35 volt and 4.3 volt descriptions the correct way around? Thanks for the review.

I believe they are correct, but because the protection trips when charging to 4.35V the capacity is less than 4.30V.

Thanks HKJ.

Thanks for the test. Can we expect a little christmas gift in the form of a test of some "hot" batteries like Sanyo 18650GA and its competitors? They must have almost dryed out in the queue!

I have not bought them yet, because I want as fresh batteries as possible. All the new cells will have to wait to next year.

I’m confused by the graphs.

Your discharge ends at 2.8v but your protection test stops at just above 3v

The protection test is a protection current test and stops at 8A for smaller cells. The voltage will depend on the cell.

Ah, I completely missed that. I was thinking it was testing the low voltage protection.

Thanks for the reply