Test/review of Efest IMR26650 4200mAh (Purple) 2017

Batteries and Chargers Rechargeable Batteries
1

Efest IMR26650 4200mAh (Purple) 2017







Official specifications:

  • Rated capacity: 4200mAh

  • Nominal voltage: 3.7V

  • Voltage at end of discharging: 2.5V

  • Max. charging current: 4A

  • Standard charge: 2A

  • Discharging current 35A

  • Pulse discharging current: 50A

  • Charging temperature range: 0°C ~ 45°C

  • Discharging temperature range: –20°C ~ 75°C

  • Inner resistance: 20mOhm

  • Cell size: 18.5 (±0.2)mm x 65.2 (±0.2)mm




This is a high current 26650 battery.











It do fairly good up to 20A, at 30A the cell is struggling a to handle the current.





At 30A I had to terminate the discharge a bit premature due to high temperature (I only had sensor on the B cell).















Conclusion

This is a fairly good high current cell, but the rating is on the optimistic side.



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
2

It must be these “premium” brands think the consumer market is full of careless morons who just care about flashy figures on their battery wraps. If they were to face lawsuits because of unsafe performance claims another day would dawn. Sheesh!

With regards to my previous “BMS as switch” question, here's a quote from the HY2120 datasheet:

“Notice: Discharging may not be enacted when the battery is first time connected. To regain normal status, CS and VSS pin must be shorted or the charger must be connected.”

Well, since I am going to use a driver which is only single mode, I guess this can work by connecting a momentary pushbutton between the CS and VSS pins. :-D

Thanks again for another review.

Cheers

3

Just look at a fair labeled cell that beats the Efest, by a lot

Golisi IMR26650 Less voltage sag and rated 35A

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Thanks for the review. :+1: