Test/Review of Eizfan IMR26650 3500mAh (Gold)

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HKJ
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Test/Review of Eizfan IMR26650 3500mAh (Gold)
Eizfan IMR26650 3500mAh (Gold)

DSC_8521
Official specifications:
  • Model No.: IMR 26650
  • Rated capacity: 3500mAh
  • Nominal voltage: 3.7V
  • Size: Diameter 26.13, height 65.56mm
  • Weight: 95g
  • Resistance: 23±2 mOhm
  • Temperature range: -20~+60 ºC
  • Monthly Self-discharge rate: Temperature range: Discharge: -20~+60 ºC, Charge: 0~45 ºC
  • Maximum discharging current: 35A
  • Maximum charging current: 6.5A
  • Maximum pulse discharging current: 65A

Eizfan%20IMR26650%203500mAh%20(Gold)-info

A high current 26650 battery according to specifications, as can be seen below that is not correct.

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DSC_8522 DSC_8523

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When the test was finished and I removed the battery from my test station the plastic wrapper was damaged due to heat, as was my test station.
This means that the curves for the second battery may be a little bit off, due to the damaged test station as was my next few battery test, until I discovered the damage and fixed it and has started a retest of the affected batteries.

Eizfan%20IMR26650%203500mAh%20(Gold)-Capacity

Some of the differene at high current is probably due to the damaged test station, but the capacity difference in the 0.2A track cannot be from that.
The curves looks like the battery can deliver 30A, but obvious it gets to hot doing it.

Eizfan%20IMR26650%203500mAh%20(Gold)-CapacityTimeHours

Eizfan%20IMR26650%203500mAh%20(Gold)-CapacityTime

Eizfan%20IMR26650%203500mAh%20(Gold)-Energy

Eizfan%20IMR26650%203500mAh%20(Gold)-PowerLoadTime

Eizfan%20IMR26650%203500mAh%20(Gold)-TripCurrent

Eizfan%20IMR26650%203500mAh%20(Gold)-Charge



Conclusion

The batteries has some capacity difference, this means that they must not be used in series and I would stay well below 30A when using them.



Notes and links

The batteries was supplied by Efan 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

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

ryansoh3
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Wow, the battery became hot enough to melt the wrapper and damage your test station? Shocked

BLF ≠ B-grade Flashlight Forum

 

HKJ
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ryansoh3 wrote:
Wow, the battery became hot enough to melt the wrapper and damage your test station? :O

Yes.

I use this type of clamp to hold the batteries:

Some of the yellow plastic melted, making the connection a bit unstable, but not enough to make it obvious when I replaced batteries. The copper rods do transfer heat rather well.

It is, of course, easy enough to fix, I just need to tighten the copper rods.

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