Eizfan IMR21700 3750mAh (Black-cyan) 2018
%202018/DSC_4713.jpg)
Official specifications:
- Model: IMR 21700
- Rated Capacity: 3750mAh
- Nominal Voltage: 3.7V
- Voltage at end of Discharge: 2.9V
- Standard charge Current : 740mA
- Max. Charge Current : 3700mA
- Max. continuous discharge Current : 30A
- Max. pulse discharge Current: 40A
- Charging temperature Range: 0C to 45C
- Discharge temperature Range: -10C / -60C
- Inner resistance: 16mohm
- Cell size : 21.8mm x 70.6mm
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-info.png)
This is a high current cell with fairly good capacity in the new 21700 size.
%202018/DSC_4712.jpg)
%202018/DSC_4711.jpg)
%202018/DSC_4714.jpg)
%202018/DSC_4715.jpg)
%202018/DSC_4716.jpg)
%202018/DSC_4717.jpg)
%202018/DSC_4718.jpg)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-Capacity.png)
The two cells tracks nicely and capacity is nearly constant independent of load. It looks like 30A is a bit much for continuous drain.
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-Temp-15.0.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-Temp-20.0.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-Temp-30.0.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-CapacityTimeHours.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-CapacityTime.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-Energy.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-PowerLoadTime.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-TripCurrent.png)
%202018/Eizfan%20IMR21700%203750mAh%20(Black-cyan)%202018-Charge.png)
Conclusion
The battery is good at delivering current, but slightly less than specified.
Notes and links
The 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