Test / Review: Keeppower 26650 4000mAh (Black)

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HKJ
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Test / Review: Keeppower 26650 4000mAh (Black)

Keeppower 26650 4000mAh (Black)

DSC_2674

Official specifications:

  • 26650 4000mAh Protected Rechargeable Battery
  • Min Capacity: 4000mAh
  • Typical Capacity: 4100mAh
  • Normal Voltage: 3.7V
  • Standard charge current 2000mA
  • In Built Safety Circuitry
  • Protection Circuit (Against overcharge, over discharge, over current and short-circuit.)
  • 4.2 volts max voltage and 3.7 volts nominal voltage


Keeppower%2026650%204000mAh%20(Black)-info

The battery does easily meet the specified capacity.
Note: The internal resistance is calculated from 6 to 10 ampere.

DSC_2672

DSC_2675 DSC_2676

DSC_2677
DSC_2678


Keeppower%2026650%204000mAh%20(Black)-Capacity

Lots of capacity, but the batteries has difference capacity especially at high loads.

Keeppower%2026650%204000mAh%20(Black)-CapacityTimeHours

Keeppower%2026650%204000mAh%20(Black)-CapacityTime

Keeppower%2026650%204000mAh%20(Black)-Energy

Keeppower%2026650%204000mAh%20(Black)-PowerLoadTime

Keeppower%2026650%204000mAh%20(Black)-TripCurrent

The protection trips at a very high value, as can be seen the output of the batteries has started to go down, before the protection trips.

Keeppower%2026650%204000mAh%20(Black)-Charge



Conclusion

This is the first keeppower battery I have seen, where I am disappointed with it, the performance is good, but I do not like the difference between the cells and the very high trip point of the over current protection.



Notes and links

Keeppower is a OEM manufacturer, i.e. many of the batteries they produce is sold with other names on them.

The batteries was supplied by Keeppower 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

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
nofearek9
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maybe something wrong with the one of the two cell ?

HKJ
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nofearek9 wrote:
maybe something wrong with the one of the two cell ?

Maybe, or maybe because Keeppower used a "cheap" China source for the battery.

Remember that Keeppower does not make LiIon batteries, they buy them and add the protection.

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

Chicago X
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Thanks for the review. Did you notice any difference in weights between the cells?

Do you think that KeepPower would send you another sample for testing? The difference in performance, if not anomalous, could be a source of concern in multi-cell apps.

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Ledsmoke
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Thank you for the test HKJ. Youve been a busy bee lately haven't you Smile Do you ever get any sleep at all?

And "what Chicago X said"

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HKJ
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Chicago X wrote:
Thanks for the review. Did you notice any difference in weights between the cells? Do you think that KeepPower would send you another sample for testing? The difference in performance, if not anomalous, could be a source of concern in multi-cell apps.

According to my scale: A:92.86 gram, B:93.24 gram, this is not much difference.

I send the result to Keeppower a few days ago, but have not got any response yet.

If Keeppower get something better, I believe there is a good possibility they will send it.

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

HKJ
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Ledsmoke wrote:
Youve been a busy bee lately haven't you Smile Do you ever get any sleep at all?

It is a good thing that the test equipment is mostly automatic, but I am behind on writing reviews (I have test data ready for some more reviews).

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

RAW74
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Thanks for all of your hard work HKJ! Your battery tests have helped me a great deal in making good battery purchases.I always check your reviews on a cell before I decide to buy/or not to.-Rick

nekdo12
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Kingkong with protection? :bigsmile:
yavi
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Great review as always!

If Panasonic keeps working on new 18650s, in a pair of years, they can roughly reach the 26650s capacity, it is a pity they don’t work on this cells size.

Hikelite
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nekdo12 wrote:
Kingkong with protection? :bigsmile:

Quite possible

 

Hikelite
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yavi wrote:
Great review as always! If Panasonic keeps working on new 18650s, in a pair of years, they can roughly reach the 26650s capacity, it is a pity they don't work on this cells size.

With a capacity rating of 0.2C , that 18650 Panasonic cell would not offer 4200mAh at 2C as the KK 26650 can do now.

 

sb56637
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Thanks very much! Frontpage’d and Sticky’d.

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