Test / Review: Efest 18650 3400mAh (Black)

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HKJ
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Test / Review: Efest 18650 3400mAh (Black)

Efest 18650 3400mAh (Black)

Protected button top

DSC_1357

Official specifications:

  • 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°)
  • Max. Discharge Current: 6800mA(ambient temperature 25°)
  • 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°, Discharge: -20 to 60°


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

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DSC_1358DSC_1359
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Efest%2018650%203400mAh%20bt%20(Black)-Capacity

The protection does prevent a full 5A discharge curve on one of the batteries. The difference in protection between the batteries is also the reason for the curves not overlapping at the higher currents.
The cell used can be discharged down to 2.5 volt, in my test I only discharges to 2.8 volt, i.e. I do not measure the full capacity. But then, not all lights will be able to use the full capacity.

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

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

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

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

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

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



Unprotected flat top

DSC_1351

Official specifications:

  • none found


Efest%2018650%203400mAh%20ft%20(Black)-info

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Efest%2018650%203400mAh%20ft%20(Black)-Capacity

The unprotected version has exactly the same very good performance as other batteries with the same cell.

Efest%2018650%203400mAh%20ft%20(Black)-CapacityTimeHours

Efest%2018650%203400mAh%20ft%20(Black)-CapacityTime

Efest%2018650%203400mAh%20ft%20(Black)-Energy

Efest%2018650%203400mAh%20ft%20(Black)-PowerLoadTime

Efest%2018650%203400mAh%20ft%20(Black)-TripCurrent

Efest%2018650%203400mAh%20ft%20(Black)-Charge



Conclusion

Both batteries are very good, the slightly low protection limit is only a problem in special applications (Discharing a 3400mAh battery in less than 40 minutes is not normal usage), not for regular usage.



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/

Edited by: sb56637 on 08/26/2014 - 17:45
Ramblings
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Whatever would we do without your battery reviews.

Much appreciation from just the average flashaholic.

You are the light of the world. Like a city on a hill, you cannot be hidden.
People do not light a lamp and then hide it away, instead they put it where it gives lig

CM2010
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Good work, as always.

kreisler
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thanks!! Smile

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vēer
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Thanks, good to see that Efest are making ,as Ezarc corrected my wrong choice of words, distributing decent batteries, makes me much more confident in my protected 2600mAh ones :D!

HKJ, youre at your best, as usual ;)!

SashiX
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vēer wrote:
Thanks, good to see that Efest are making decent batteries, makes me much more confident in my protected 2600mAh ones :D!

HKJ, youre at your best, as usual ;)!


I’d say they (as many others brands too, of course) “choose” decent batts to put their wrap on them :bigsmile:
Anyhow, good cell and good review as always WinkBeer

sb56637
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Thanks a lot! Frontpage’d and Sticky’d.

Budget Light Forum ...where Frugal meets with Flashlight!

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Thanks HKJ.
Appreciate all your reviews.

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balloonix
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Like everytime a perfect review. I ordered 2 pcs of those batteries some weeks ago and made some tests with the same results. Maximum current was 5.8 Amps and cut off was 2,30V. For user im EU it is a good choice because the batteries where delivered from a warehouse in the EU.

applevalleyjoe
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Can you get these batteries in the US and if so, where and how much?