Test/Review of Efest IMR18650 3100mAh (Purple) 2014

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HKJ
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Test/Review of Efest IMR18650 3100mAh (Purple) 2014

Efest IMR18650 3100mAh (Purple) 2014

DSC_6281

Official specifications:

  • Top: flat top
  • Bottom: non-protected
  • Typical Capacity: 3100mAh
  • Min capacity: 3100mAh
  • Max discharge current: 10A
  • Pulse discharge current: 20A    
  • Quick charge current: 3000mA (1C)
  • Quick discharge current: 2000mA
  • Cycle life: 300 times
  • Charge cut-off voltage: 4.2V ± 0.5V
  • Charge cut-off current: 5A
  • Initial Impedance: Max: 15mOhm
  • Discharge cut-off voltage: 3.0V
  • Temperature: discharge temperature range:-10°C—60°C, charge temperature range: 0°C—40°C
  • Storage: 1 year:-20°C—25°C, 3 months:-20°C—45°C, 1 month:-20°C—60°C
  • Size: weight: 50g, Length: 65 mm, Diameter: 18mm


Efest%20IMR18650%203100mAh%20(Purple)%202014-info

High power and high capacity in the Efest purple line of high current cells.

DSC_6279 DSC_6280

DSC_6282 DSC_6283

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Efest%20IMR18650%203100mAh%20(Purple)%202014-Capacity

Looking at this curve I will say that 20A is a bit high for continous load, but 10A is handleded very fine.

Efest%20IMR18650%203100mAh%20(Purple)%202014-CapacityTimeHours

Efest%20IMR18650%203100mAh%20(Purple)%202014-CapacityTime

Efest%20IMR18650%203100mAh%20(Purple)%202014-Energy

Efest%20IMR18650%203100mAh%20(Purple)%202014-PowerLoadTime

I had an accident during testing and I am missing one cell in some tests. The problem was that my load did not turn off after the 20A and discharged the cell completely.

Efest%20IMR18650%203100mAh%20(Purple)%202014-TripCurrent

Efest%20IMR18650%203100mAh%20(Purple)%202014-Charge



Conclusion

The cell cannot match the ultra high current cells in power, but easily surpass them in energy at 10A. This is very good performance.

I will call it a acceptable cell.



Notes and links

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

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Edited by: HKJ on 08/25/2014 - 11:34
D10ten
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Thank you HKJ for the review. I compared this to the NCR18650BD using HKJ’s 18650 comparion and they were exactly the same.

leaftye
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As always, great test!  I'm especially happy to see this because I'm actually about to start testing a pair of these today.  

 

You might want to start using a darker gray for your 20A graphs because it's almost impossible to see on my screen.

The low mode should be lower.

dangerous
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D10ten wrote:
Thank you HKJ for the review. I compared this to the NCR18650BD using HKJ’s 18650 comparion and they were exactly the same.
NCR18650BE*

http://dampfakkus.de/akkutest.php?id=531
http://dampfakkus.de/akkutest.php?id=536

BLF

D10ten
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Strange, I thought BD was the hybrid battery (successor of the PD) capable of 10A discharge, while BE was the cheaper version of NCR18650B with only a 3.5A discharge.