Efest IMR20700 3000mAh (Purple) 2017
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Official specifications:
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Rated capacity: 3000mAh
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Nominal voltage: 3.7V
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Voltage at end of discharging: 2.5V
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Max. charging current: 4A
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Standard charge: 2A
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Discharging current 30A
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Charging temperature range: 0°C ~ 45°C
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Discharging temperature range: –20°C ~ 75°C
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Inner resistance: 20mOhm
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Cell size: 20 (±0.20)mm x 70 (±0.2)mm
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Efest do also have a battery in one of the new sizes that is slightly larger than 18650. The extra size is used for better high current handling in this cell
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The two batteries are not perfectly matched, there is a small difference. The batteries have fairly constant capacity at any current.
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At 30A they get very warm and I had to stop shortly before they where empty.
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Conclusion
This is a nice high current battery and the slightly large size compare to a 18650 can be seen on the improved performance.
This battery is mostly for people that needs well above 10A, for lower currents look at a 18650.
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