Efest IMR18650 2500mAh (Purple) BT 2014



Official specifications:

• Weight: 50g
• Size: 65.69mm(L)x18.30mm(D)
• Top: Button top
• Bottom: unprotected
• Typical Capacity: 2500mAh
• Discharge temperature range: -20°C—60°C
• Charge temperature range: 0°C—45°C
• Storage: 1 year: -20°C—25°C, 3 months: -20°C—45°C, 1 month: -20°C—60°C

Efest high current 18650 in button top version, again with the optimistic 35A rating.










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.















Conclusion

The button top will add a very small resistance and reduce the performance slightly at very high currents.
Usual a battery with unspecified cell will not get better rating than acceptable, but there is no doubt this is a very good cell that is used here.



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