AWT 40A 3000mAh 18650 Bench Retest Results...only a 20A battery, damaged at over 30A

Discussion in 'Batteries and Chargers' started by Mooch, Dec 8, 2015.

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  1. Mooch

    Mooch Electron Wrangler Verified Member ECF Veteran

    Supporting member
    May 13, 2015
    Tested at 10A-40A constant current and 30A-60A pulsed. These cells were purchased by me 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 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.

    image.jpg image.jpg image.jpg image.jpg

    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 confusingly labeled 3000mAh battery with only a 20A continuous discharge rating (CDR). It gets badly damaged from just one discharge at 35A and 40A. Its appearance is close to the HG2's but its performance is just below it. Its pulse performance is average for a 20A cell, up to about 40A without the voltage sagging very low or overheating.


    Continuous-Current Test Results
    image.jpg


    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.jpg image.jpg


    Comments
    • A recent Facebook post by a vendor mentioned that they are changing from a four-legged top cap to a three-legged top cap cell. Sounds like they might be switching to a Samsung 30Q (of unknown grade). These tests were done with the four-legged top cap cells.
    • image.jpg
    • At 10A it reached about 2750mAh. This is average performance for a 3000mAh-rated cell at 10A.
    • At 15A the maximum temperature reached 72°C. This is below the average temperature of a cell operating at its continuous discharge rating (CDR).
    • At 20A the maximum temperature reached 83°C. This is above the average temperature of a cell operating at its continuous discharge rating (CDR) but within the upper limit. It indicates that we're operating at or near the CDR for this cell. It is the same temperature as the HG2 at 20A but its capacity is a bit lower than the HG2.
    • At 25A the temperature rose to 101°C. This is way too high for a cell operating at its CDR and is just above my 100°C safety limit.
    • At 30A and 35A the temperature rose to 110°C and 117°C. This is way too high for a cell operating at its CDR and is above my 100°C safety limit. The voltage is sagging a great deal at these current levels.
    • At 40A, the rating given by the manufacturer, the voltage quickly plummeted. This is clearly not a 40A cell.
    • Another discharges at 20A showed significant damage to the cell from just one discharge at 35A and 40A.
    • I am setting a CDR of 20A for this cell. Its temperature at this discharge current level is the same as the temperature of the HG2 operating at its CDR. While operating any cell near its rated maximum current causes damage to the cell, I would expect good 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-60A, 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
     
    xtwosm0kesx, Phassat, puffon and 5 others like this.
  2. Phassat

    Phassat Super Member ECF Veteran

    Nov 9, 2014
    Planet Earth
    Mooch... Been looking for you. I just purchased IMREN 40A, 3000mah. Would like to know if you tested this cell. The store that was selling it to me said it is better than LG HG2
     
  3. RuDawg7890

    RuDawg7890 Ultra Member Verified Member ECF Veteran

    There's a link in Mooch's sig to all of his battery tests thus far, and in the bottom of his last post above.
     
  4. Phassat

    Phassat Super Member ECF Veteran

    Nov 9, 2014
    Planet Earth
    It doesn't display correctly... It linked to someone else post ... I'm using an iPhone
     
  5. Mooch

    Mooch Electron Wrangler Verified Member ECF Veteran

    Supporting member
    May 13, 2015
    Perfect timing...it's in testing now. I'm behind on getting the reports written up so I'll be posting the results for this one by the end of the week or so.
     
    Phassat likes this.
  6. Phassat

    Phassat Super Member ECF Veteran

    Nov 9, 2014
    Planet Earth
    Great... Will look forward to read your review on it.
     
    Mooch likes this.
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