Test/review of Eizfan IMR20700 3100mAh (Black-yellow) 2018

Eizfan IMR20700 3100mAh (Black-yellow) 2018

Official specifications:

  • Rated Capacity: 3100mAh

  • Continuous Discharge Current: 30A

  • Max. Short Peak Discharge CC: 40A

  • Rated Voltage: 3.7V

  • Internal Resistance: <30mOhm

  • Cut-off Discharge Voltage: 2.5V

  • Charge Upper Limit Voltage: 4.20±0.05V

  • Charging Metod: CC/CV 4.20V

  • Charging Time(Std): 4.0hours

  • Standard Charging Current: 0.2C A

  • Charging Current: 0.5C A

  • Standard Discharging Current: 0.2C A

  • Fast Discharging Current: 0.5C A

  • Max Discharging Current: 2C A

  • Weight: about 60g

  • Size: 20*70mm

  • Version: Flat Top

  • Operational Temperature: Charge (0 ~ 50°C)

This is high current cells and due to that the capacity is fairly low for this size.

The discharge curves tracks nicely at any tested current, at 30A I terminated the discharge a bit early due to the temperature.


The battery works well above 10A, but may be too hot at 30A continuous discharge.

Notes and links

Batteries was supplied by Eizfan (Efan) 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
Graphical comparison to 18650 and other batteries
Table with all tested LiIon batteries

Ok, nice test, Eizfan did however exaggerate the capacity of his rewrap but I think they thought to use the 3100mAh 20700 YongdeLixin cell (the one used first by Vapcell on their Gold (with white writing) 20700 3100mAh 30A, in the Efest 20700 3100mAh and in EBAT 20700 3200mAh (model E8-20P32 of metallic blue color)) as basic cell but they seem (YongdeLixin) to have problems of quality and regularity in their production so they have temporarily stopped the sale of this model what Eizfan could not predict so they fell back on Molicel INR20700A but not of first quality (their grades seem really bad) unlike that officially distributed by Molicel/NPE which are much better and especially do not heat as much at 30A continuous with a much better capacitée), brief damage, history to follow, see if it changes cell soon for this rewrap…