Test/Review of Efan IMR18650 2500mAh (Purple)

Efan IMR18650 2500mAh (Purple)

Official specifications:

  • Capacity, Std. charge / discharge: 2500mAh
  • Nominal Voltage, average of Std. Discharge: 3.70V
  • Standard Charge: constant current 1250mA, Constant voltage 4.20V, End current(Cut off) 50mA
  • Fast Charge: Constant current 4000mA, Constant voltage 4.20V, End current(Cut off) 100mA
  • Max. Charge Voltage: 4.20V
  • Max. Charge Current: 4000mA
  • Standard Discharge: Constant current 500mA, End voltage(Cut off) 2.5V
  • Fast Discharge: Constant current 10000mA, 20000mA, End voltage(Cut off) 2.5V
  • Max. Discharge Current: For continuous discharge 35000mA
  • Weight Approx.: Max. 48.0G
  • Operating Temperature: charge 0 ~ 50°C, Discharge -20~ 75°C
  • Storage Temperature: 1 month -20 ~ 60°C, 3 months -20 ~45°C, 1 year -20 ~ 20°C
  • Dimension: (D)18.3 + 0.2/-0.3 mm, (H) 66.0 ± 0.2 mm

This is a very high current battery, but the 35A rating might be a bit optimistic.

These curves shows a very good battery, there is a good tracking between the batteries and not much capacity drop from 0.2A to 20A.


This cell has very good high current performance.

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

Thanks for the review!

Would you say it is comparable to the Efest IMR 18650 2500mAH 30A Battery?

Yes. The differences in performance may be due to different age of the cell.

I’ve heard they may be rewrapped VTC4.

Use my comparator and compare the discharge curves at both low and high currents. It is easy to see if it possible.

This seems to be the group with the best cells overall for high amps.The Basen 2.5 and AWT (not to be confused with the well known AW high drain cells)2.5Ah clearly have the same,very good,cell under the wrapper.would like to know what that cell is.The E fest 2.5 purple is slightly below on voltage sag,the same as the Efan,with the same discharge curve for both,just,about 100mAh more capacity for the E fest,production variation?The wrappers are even the same purple!I am sure all these cells are rewraps of at least 2 cells.One is the LG HE2 which HKJ has not tested as far as I can see,Sony is probably another.The KeepPower 2.5 IMR is up there with the basen and AWT,but again with maybe 150mAh less capacity but slightly less sag at the start,at all currents.They all seem to outperform the Samsung 20R.This group of cells seems the most interesting for the Eagle Eye X6 BLF special.

I do not see discharge data for the VTC4, only VTC5. The VTC5 discharge does look similar to this one (but stretched out).

I’m keeping my eye on this thread. Thanks for the info HKJ.

The VTC4 is there listed as Keeppower IMR 2600mah . These will either be Samsung 25rs or LG HE2s

Thanks Dru_dragon!

Is LG Chem ICR-18650 HE2

The KeepPower
IMR 2600, is the Sony Konion US 18650 VTC5.
The Makita bought all VTC5.
This is the reason that does not exist in the market .
I do not know how many managed to buy the KeepPower, but I think it would be not big lots , because neither you can find anywhere .
The KeepPower IMR 2500 is the LG Chem ICR HE2.
The new will be the LG HE4.

These I know , these are written . If I am wrong , please be deleted , so there is no misinformation

The Efan 2500, has been under the label of the LG Chem ICR HE2 also