Test/review of Efest IMR20700 3100mAh (Purple) 2018

HKJ · 2018-08-20T11:49:01.000Z

Efest IMR20700 3100mAh (Purple) 2018

Official specifications:

Rated capacity: 3100mAh
Nominal voltage: 3.7V
Voltage at end of discharging: 2.5V
Maximum charging current: 4A
Standard charging current: 2A
Maximum discharge current: 30A
Charging temperature range: 0°C ~ 45°C
Discharging temperature range: –20°C ~ 75°C
Inner resistance: 20mOhm

The batteries are not perfectly matches, but fairly close. They can handle 20A with problems, but at 30A they get too hot.

I forgot to mount the temperature sensor on one of the batteries.

Conclusion

This is a nice high current battery and the slightly large size compare to a 18650 can be seen on the improved performance.
This battery is mostly for people that needs well above 10A, for lower currents look at a 18650.

Notes and links

The batteries was supplied by Efest 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

DavidEF · 2018-08-21T02:31:09.000Z

I dunno. I still feel like there ought to be more gain moving to such a larger cell. It has nearly one third more volume than 18650 size. Shouldn’t we be getting solid 25A+ performance AND ~3400mAh capacity at the same time?