Test/Review of Efest IMR18500 1000mAh (Purple) 2014

Batteries and Chargers Rechargeable Batteries
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Efest IMR18500 1000mAh (Purple) 2014



Official specifications:

  • Capacity: 1000mAh
  • Min. Capacity: 1000mAh
  • Nominal voltage: 3,7V
  • Charge voltage: 4,2V ± 0,05
  • Discharge voltage: 3,0V
  • Max. discharge current: 15A (15C)
  • Max. charge current: 1A (1C)
  • Positive pole: Flat Top
  • Protection circuit (BMS): no (unprotected)
  • Chemical composition: LiMn (IMR)
  • Diameter: 18,30mm ± 0,1
  • Height: 49,80mm ± 0,1
  • Weight:40g ± 1
  • Charging methode: CC-CV




A 18500 cell with a very high maximum current, the rating is higher than for many 18650 cells. This means the cell has a fairly low capacity.











The curves overlaps fairly well and the capacity is nearly constant. This is very good performance all the way up to 15A.















Conclusion

These battery has very good high current performance, but the size limits the capacity (If you have 15mm more length, you can get more than twice the capacity).
With the performance of these cells, I will call it a good battery.



Notes and links

The batteries was supplied by Akkuteile.de 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

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Thanks HKJ for another great review.

I like the 18500 format for lights that have some power while still being pocketable.
Some modded Solarforce L2m come to mind :heart_eyes:

This cell has more capacity than the AW IMR 18500 (red) and holds it very well at higher current. Seems to be truly manganese based, capacity suggests LiNiCoMn chemistry.