Efest IMR26650 5200mAh (Purple) 2016



Official specifications:

• Nominal capacity: 5200mAh
• Minimum capacity: 5100mAh
• Nominal voltage: 3,7V
• Charge cut-off voltage:: 4.2V ± 0,1V
• Discharge cut-off voltage: 2.5V
• Max discharge current continuous/pulse: 15A / 40A
• Cycle life: 500 cycles to 60%
• Chemistry: LiNiMnCoO2
• Diameter: 26,22mm ± 0,15mm
• Length: 66,2mm ± 0,15mm
• Weight: 92g ± 1

This is a high capacity 26650 with fairly high current.











The discharge curves tracking is good, at 15A the capacity drops significantly and the battery gets too hot.



The batteries gets fairly warm at 10A, but can handle a full discharge.



At 15A they get too hot and I terminates the discharge a bit early, maximum temperature was about 86°C



At 20A the temperature raises to the same level, but the battery is empty before I can register it and stop.















Conclusion

The batteries has good performance with high capacity and performs fine up to 10A, above that it is best to use pulse discharge, to keep the temperature down.



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