Enercig 20700 4000mAh EC-27B (Red)
/DSC_1832.jpg)
Official specifications:
- Typical capacity: 4250mAh
- Minium capacity: 4000mAh
- Weight:60g ±3g
- Diameter: 20.35 mm ±0,1 mm
- Length: 70.30 mm ±0,25 mm
- Nominal voltage: 3,6 Volt
- Charge termination: 4,20 Volt ±0,05 Volt
- Discharge termination: 2,50 Volt
- Maximum charge current: 4,0 A (1C)
- Maximum continious discharge current: 15A (5C)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-info.png)
This is very good discharge curves, they track perfectly. The rated 15A discharge current looks very reasonable.
/DSC_1831.jpg)
/DSC_1833.jpg)
/DSC_1834.jpg)
/DSC_1835.jpg)
/DSC_1836.jpg)
/DSC_1837.jpg)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-Capacity.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-Temp-10.0.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-Temp-15.0.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-Temp-20.0.png)
At 20A the cell gets too hot and I had to stop the discharge.
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-CapacityTimeHours.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-CapacityTime.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-Energy.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-PowerLoadTime.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-TripCurrent.png)
/Enercig%2020700%204000mAh%20EC-27B%20(Red)-Charge.png)
Conclusion
This size has more capacity and slightly higher voltage than 18650, without being much larger.
The cell is a very good.
Notes and links
The batteries was supplied by ENERDan 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