Mica 60A 26650 Bench Test Results...only a 26A 3500mAh battery!

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Mooch

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    Tested at 10A-60A constant current and 20A-60A pulsed. These cells were purchased for the purposes of testing thanks to the wonderful donations from so many of you. Thank you! To prevent any confusion with the eGo-type "batteries", I use the term "cell" here to refer to a single 18650, 26650, etc.

    Disclaimer
    The statements, conclusions, and recommendations I make based on these tests are only my personal opinion. Carefully research any battery you are considering using before purchasing.

    Testing cells at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved and how to minimize them. My safety precautions are the ones I have elected to take and you should not assume they will protect you if you attempt to do any testing. Do the research and create your own testing methods and safety precautions.

    image.jpeg image.jpeg image.jpeg image.jpeg


    A note regarding current ratings and my testing
    If the cell has only one current rating number on it, or if it says "max discharging current" then I have to assume that the company is stating that the cell can be discharged at that current level in any way, including continuous. Otherwise they would have listed the current rating with two numbers as other companies have done. Or they would have labeled the rating on the wrap as "pulse" or "burst". Battery buyers should not have to hunt down what the number on the wrap means. I will be testing batteries at the rating listed on the wrap and pointing out when they fail to meet that listed rating.


    Bottom Line
    In my opinion this is a good 26A 3500mAh battery. If allowed to run hot though, it could be rated as high as 30A. Its appearance and performance is essentially identical to the MXJO 35A 3500mAh and MNKE 35A 3500mAh and seems to use the same cell. Its voltage quickly collapses at the 60A rating on the wrap but can be pulsed to about 40A with decent results.


    Continuous-Current Test Results
    image.png


    Pulsed-Current Test Results
    These tests are done to show the performance of the cell at higher pulsed current levels. If you are running your mod at these levels be aware that you risk overheating, and possibly venting, the battery if there is a malfunction or accidental pressing of your mechanical mod's button.
    image.png image.png


    Comparion to MXJO and MNKE 26650
    image.png


    Comments
    • At 10A it reached a bit over 3300mAh. This is good performance for a 3500mAh-rated cell operating at 10A so I am rating this cell at 3500mAh.
    • Its temperature at 15A was 55°C, way below the average for a cell operating at its CDR.
    • At 20A the temperature rose to 67°C. This is below the average for a cell operating at its CDR.
    • At 25A the temperature rose to 76°C. This is just below the average for a cell operating at its CDR.
    • At 30A the temperature rose to 82°C. This is at the upper limit for a cell operating at its CDR.
    • At 35A the temperature rose to 87°C. This is too high a temperature for a cell operating at its CDR. There is a lot of voltage sag indicating that it's operating way beyond its rating. The loss in capacity was significant.
    • At 60A the voltage instantly dropped to a useless level.
    • Another two discharges at 25A showed almost no change other than what is expected by running a cell near its CDR.
    • I am setting a CDR of 26A for this cell since at this current level its operating temperature is at the average for a cell operating at its CDR. While operating any cell near its rated maximum current causes damage to the cell, I would expect decent cycle life from this cell at 26A.
    • I have included pulsed discharges but I haven't set pass/fail standards for pulse testing yet. The discharges were done at 5sec on/30sec off, down to 2.5V. One chart shows the entire discharge at each level. The other chart is zoomed in to show the first 5 minutes to make it easier to see the voltage sag at different current levels.

    To see how other cells have tested and how hard you can safely push them, check out these links:
    List of Battery Tests | E-Cigarette Forum

    18350 Safety Grades and Pulse Performance Data | E-Cigarette Forum

    18650 Safety Grades -- Picking a Safe Battery to Vape With | E-Cigarette Forum

    26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum
     

    sonicbomb

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    Feb 17, 2015
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    Ooh a good one for a change.

    I've said this before and I promise to say it again, Mooch is the bollocks.
    For those unfamiliar with British vernacular that word can mean..

    1. Utter rubbish, unworthy, untrue
    2. Male reproductive organs
    3. Something truly excellent

    17 internet points will be awarded for choosing the correct meaning.
     
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    Mooch

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  • May 13, 2015
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    Mooch, why is it that 26650 batteries can't match or exceed the amperage of 18650s. I don't pretend to know. One would think the larger battery would be able to push higher amps...

    They're designed for capacity (runntime), not power (amps). When that's done the internal resistance of the battery is higher and that causes greater voltage sag. This increased voltage sag means that the battery hits the mod's low voltage cutoff point sooner.
     

    EddieAdams

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    They're designed for capacity (runntime), not power (amps). When that's done the internal resistance of the battery is higher and that causes greater voltage sag. This increased voltage sag means that the battery hits the mod's low voltage cutoff point sooner.
    So if they designed a 26650 with focus on amps, would they then be able to create a 26650 with higher amp draw than top performing 18650?
     
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