Efest IMR20700 3100mAh (Purple) 2018
%202018/DSC_0636.jpg)
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
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-info.png)
%202018/DSC_0635.jpg)
%202018/DSC_0637.jpg)
%202018/DSC_0638.jpg)
%202018/DSC_0639.jpg)
%202018/DSC_0640.jpg)
%202018/DSC_0641.jpg)
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-Capacity.png)
The batteries are not perfectly matches, but fairly close. They can handle 20A with problems, but at 30A they get too hot.
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-Temp-20.0.png)
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-Temp-30.0.png)
I forgot to mount the temperature sensor on one of the batteries.
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-CapacityTimeHours.png)
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-CapacityTime.png)
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-Energy.png)
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-PowerLoadTime.png)
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-TripCurrent.png)
%202018/Efest%20IMR20700%203100mAh%20(Purple)%202018-Charge.png)
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