Vape Haze 38A 2600mAh 18650 Bench Test Results...a good 20A battery, damaged at 30A-35A

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Mooch

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  • May 13, 2015
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    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 batteries 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.

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    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 cells 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 performing 20A continuous discharge current (CDR) cell with a capacity of about 2600mAh. But a single discharge at 30A, 35A, and 38A (its rating on the wrap) damaged the cell.


    Continuous-Current Test Results
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    Pulsed-Current Test Results

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    Comments
    • At 10A it reached about 2375mAh. This is average performance for a 2600mAh-rated cell at 10A.
    • At 15A the maximum temperature reached 70°C. This is below the average temperature of a cell operating at its continuous discharge rating (CDR).
    • At 20A the maximum temperature reached 82°C. This is above the average for a cell operating at its CDR but just within the range of acceptable values. The capacity was only a bit less than a Samsung 25R at 20A down to 3.2V.
    • At 25A the temperature rose to 97°C. This is too high for a cell operating at its CDR and is very close to my safety limit of 100°C.
    • Discharges at 30A and 35A showed increasing voltage sag and loss of capacity. The temperature rose to 108°C @ 30A and 116°C @ 35A, significantly exceeding my safety cutoff of 100°C. This is clearly not a 38A cell.
    • Another 20A discharge showed that damage was done to the cell during the higher current discharges. I do not recommend running this cell at beyond 25A continuous.
    • I am setting a CDR of 20A for this cell. Its temperature is high but acceptable. While operating any cell near its rated maximum current causes damage to the cell, I would expect decent cycle life from this cell at 20A.
    • I have included pulsed discharges but I haven't set pass/fail standards for pulse testing yet. The discharges were done at 30A-70A, 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
    18650 Safety Grades -- Picking a Safe Battery to Vape With | E-Cigarette Forum
     
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