Test/Review of Efest 18650 3400mAh bt (Black) 2014

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HKJ
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Test/Review of Efest 18650 3400mAh bt (Black) 2014
Efest 18650 3400mAh bt (Black) 2014

DSC_4098

Official specifications:
  • Number: 18650 3400mAh
  • Specifications:3400mAh 3.4Ah
  • Nominal Capacity: 3400mAh (0.2C, 2.50V discharge)
  • Minimum Capacity: 3250mAh(0.2C, 2.50V discharge)
  • Charging Voltage: 4.2 ±0.05 V
  • Nominal Voltage: 3.6V
  • Charging Method: CC-CV (constant voltage with limited current)
  • Charging Current: Standard charge: 170mA, Rapid charge : 3400mA
  • Charging Time: Standard charge : 3hours, Rapid charge : 2.5hours
  • Max. Charge Current: 3400mA(ambient temperature 25°C),
  • Max. Discharge Current: 6800mA(ambient temperature 25°C)
  • Discharge Cut-off Voltage: 2.50V
  • Cell Weight: 55g max
  • Cell Dimension: Height : 69.75mm max, Diameter : 18.57mm max
  • Operating Temperature: Charge : 0 to 45°C, Discharge: -20 to 60°C

Efest%2018650%203400mAh%20bt%20(Black)%202014-info

As usual with this type of cell I do not test the full capacity, because I stop at 2.8 volt, not the allowed minimum of 2.5 volt.

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DSC_4099 DSC_4100

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Efest%2018650%203400mAh%20bt%20(Black)%202014-Capacity

Very nice discharge curves. Due to the protection circuit the 5A curve is a bit low and one of the batteries stops before it is fully discharge.

Efest%2018650%203400mAh%20bt%20(Black)%202014-CapacityTimeHours

Efest%2018650%203400mAh%20bt%20(Black)%202014-CapacityTime

Efest%2018650%203400mAh%20bt%20(Black)%202014-Energy

Efest%2018650%203400mAh%20bt%20(Black)%202014-PowerLoadTime

Efest%2018650%203400mAh%20bt%20(Black)%202014-TripCurrent

The protection trips at 6A, but, of course, the limit is lower for continuous draw.

Efest%2018650%203400mAh%20bt%20(Black)%202014-Charge



Conclusion

This is a very good battery.
The protection circuit limits the maximum continuous draw to 5A.



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

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

nikanon
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Nice review as always HKJ !

Great to have you here and great to have your website full of usefull information !

RaceR86
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Thank you for the review!

BLF LED database – collaboration spreadsheet and latest news about where to buy LEDs
http://budgetlightforum.com/node/19342

MRTdiver
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cat eyes wrote:
what is the base cell ?? is it panasonic, or LG from korea ??

 

In HKJ's table it says Cell:  Panasonic NCR18650B

נֵר־לְרַגְלִ֥י דְבָרֶ֑ךָ וְ֝אֹ֗ור לִנְתִיבָתִֽי   (Psa 119:105)