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Thread: Test/Review of Keeppower 26650 4000mAh (Black)

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    Default Test/Review of Keeppower 26650 4000mAh (Black)

    Keeppower 26650 4000mAh (Black)



    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




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











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











    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.





    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 flashlight, battery and charger information: lygte-info.
    More than 200 battery reviews and 80 charger reviews.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  2. #2

    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    One hint: it is basically impossible to tell apart to colors in the discharge graph if the legend is only 1 pixel wide.

    Whats up with the 2 strongest current drops? Logic suggests that these are the highest discharge currents, but non of the high current in the legend have the salmon color the lowest curve has.

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    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    Quote Originally Posted by IMSabbel View Post
    Whats up with the 2 strongest current drops? Logic suggests that these are the highest discharge currents, but non of the high current in the legend have the salmon color the lowest curve has.
    Salmon is 10A discharge for the "A" cell.

  4. #4
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    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    Quote Originally Posted by IMSabbel View Post
    One hint: it is basically impossible to tell apart to colors in the discharge graph if the legend is only 1 pixel wide.

    Whats up with the 2 strongest current drops? Logic suggests that these are the highest discharge currents, but non of the high current in the legend have the salmon color the lowest curve has.
    The legend is part of the charting package I uses, I do not know if it is possible to change it.

    Generally it is not a huge problem to relate the curves to the legend, because they nearly always are in sequence.
    My website with flashlight, battery and charger information: lygte-info.
    More than 200 battery reviews and 80 charger reviews.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  5. #5

    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    Quote Originally Posted by Shadowww View Post
    Salmon is 10A discharge for the "A" cell.
    Ah, Ok. But this makes it a HUGE difference between both cells. I mean, factor 2 difference in capacity between 2 cells of the same type with just 2.5C discharge current?

  6. #6

    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    Thanks for the comprehensive review HKJ.

    Where can I pick these up at? I googled them but found only Lipos in 26650 size.
    In Him (Jesus Christ) was life; and the life was the light of men. And the light shineth in darkness; and the darkness comprehended it not.
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    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    Quote Originally Posted by vestureofblood View Post
    Where can I pick these up at? I googled them but found only Lipos in 26650 size.
    With Keeppower it is difficult to say where you can get the batteries. Anybody can order a pile of batteries from them, either with the Keeppower name or with another name. The problem is you have to order a many batteries, i.e. it will usual be dealers that orders from them.

    It is not that difficult to find 26650 batteries, the problem is finding some in top quality.
    My website with flashlight, battery and charger information: lygte-info.
    More than 200 battery reviews and 80 charger reviews.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

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    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    Excellent review as always. HKJ!

    Many thanks for your time & effort.
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    Default Re: Test/Review of Keeppower 26650 4000mAh (Black)

    Great review, I didn't even know these were available, I'm very happy with my Keeppower 3100mAh cells and I'll be ordering these to replace my unprotected no name cells.

    Norm

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