Test/review of Keeppower 18650 3120mAh P1831R (Black) 2017

HKJ · 2018-02-25T15:59:36.000Z

Keeppower 18650 3120mAh P1831R (Black) 2017

Official specifications:

Part No.: P1831R
Protected 18650 Li-ion Rechargeable Battery
Minimum Capacity: 3000mAh
Typical Capacity: 3120mAh
Normal Voltage: 3.7V
Maximum Continuous Charging Current: 5A
Maximum Continuous Discharging Current: 15A
In Built Safety Circuitry
Protection Circuit (Against over charge, over discharge, over current and short-circuit.)
4.20V maximum voltage and 2.50V cut-off voltage
Over 500 charge-discharge cycles
Max. Size: 18.8 x 69.0mm
Weight: 48g
Max. 15A Continuous Discharge Current

A protected battery that can deliver a lot of current and has good capacity.

The discharge curves tracks very fine.
The B battery jumps a bit in voltage, it looks like a loose connection in my test setup.

A full discharge at 15A is a bit much for this battery, it gets rather hot. I had to stop one of the discharges.

At 15A I had to stop both discharges due to temperature.

Conclusion

This is a good cell, but the build in protection do not trip on overload (It will probably trip on higher currents).

Notes and links

The battery 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

AndyMac2272 · 2019-08-06T00:10:46.000Z

I just purchased 4 of these batteries. Question: Would it be ok to use them in a Thrunite TN42?

d_t_a · 2019-08-06T10:43:41.000Z

This is a good cell, but the build in protection do not trip on overload (It will probably trip on higher currents).

I wonder at what possible current will it trip?
Also, having a protection circuit adds a bit of resistance, isn’t it?

HKJ · 2019-08-06T10:56:14.000Z

d_t_a:

Also, having a protection circuit adds a bit of resistance, isn’t it?

Yes, protection add a small resistor to measure current. The resistor is the on resistance of the mosfets.
Usual the chip will trip when the voltage drop is in the 0.1 to 0.2V range across the mosfets, the exact voltage depends on the chip (A often used chip DW01 is 0.15V).