Efest Metallic Purple 35A 4200mAh 26650 Bench Test Results...just a 23A battery but 4300mAh

Discussion in 'Batteries and Chargers' started by Mooch, Jun 8, 2016.

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  1. Mooch

    Mooch Electron Wrangler Verified Member ECF Veteran

    Supporting member
    May 13, 2015
    These cells were donated for the purposes of testing by Efest. Thank you! To prevent any confusion with the eGo-type "batteries", I use the term "cell" here to refer to a single 18350, 18650, 26650, etc.

    While the test results are hard data, the conclusions and recommendations I make based on these tests are only my personal opinion based on my criteria for setting a rating. Carefully research any cell 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.

    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 continuously.

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    Bottom Line
    This new Efest uses a translucent wrap that gives it a metallic look. It tested as a 23A 4300mAh cell that is identical in appearance and performance to the Basen and Brillipower 4500mAh cells. When run at its 35A continuous rating it gets hot enough to boil water. This Efest still has the useless "pulse" rating in large lettering on the wrap but does list both the continuous and pulse current ratings. Unfortunately, the ratings are exaggerated. But because it uses the same cell as the 4500mAh Basen's and Brillipower's, it is one of the better performing 26650's. As all of the new Efests have this translucent purple wrap I suspect that this cell will replace both the solid purple and the green 4200mAh cells.


    Continuous-Current Test Results
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    Pulsed-Current Test Results
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    Comments
    • At 10A continuous it reached about 4150mAh. This is very high for a 4200mAh-rated cell at 10A so I am rating this cell at 4300mAh.
    • At 15A continuous the temperature rose to 58°C. This is significantly below the average temperature of a cell running at its continuous discharge rating (CDR).
    • At 20A continuous the temperature rose to 72°C. This is a few degrees below the average temperature of a cell running at its continuous discharge rating (CDR).
    • At 25A continuous the temperature rose to 88°C. This is above the average for the temperature of a cell running at its CDR and is an indication that we are operating at beyond the cell's true rating.
    • At 30A continuous the temperature rose to 98°C. This is way above the average temperature of a cell running at its CDR and is an indication that we're above the cell's true rating.
    • At 35A continuous, the cell's rating from Efest, the temperature rose to 102°C. This is a ridiculously high temperature and is above my 100°C safety limit. Two additional discharges at 35A showed clear damage being done to the cell. This is definitely not a 35A cell.
    • I am setting a CDR of 23A for this cell. Operating at that level would bring the temperature of this cell up to near the average of a cell operating at its CDR. While operating any cell near its rated maximum current level causes damage to the cell, I would expect decent cycle life from this cell at 23A continuous.
    • 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 Battery Ratings -- Picking a Safe Battery to Vape With | E-Cigarette Forum
    26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum
     
  2. sonicbomb

    sonicbomb Vaping Master Verified Member ECF Veteran

    Feb 17, 2015
    1187 Hunterwasser
    Seems to be a pretty good 26650 (for now)

    [​IMG]
     
    MikeyConti, r77r7r and Baditude like this.
  3. MegaVap

    MegaVap Super Member Verified Member ECF Veteran

    Nov 20, 2010
    Texas, US of A
    Will you be testing the Hohm Grown 26650 @Mooch ?
     
  4. Mooch

    Mooch Electron Wrangler Verified Member ECF Veteran

    Supporting member
    May 13, 2015
    I hope to be testing it soon.
     
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  5. gorman

    gorman Super Member Verified Member ECF Veteran

    Jul 19, 2011
    Milan, Italy
    The security verification code might be worth mentioning, considering we're constantly invaded by fake. Unless cheaters crack the code, it should provide a modicum of security.

    I received a couple of these today, after ordering on Amazon from a (so it seems) reputable vendor. I was actually upset because on Amazon it displayed the green ones, so I started looking for Mooch's tests on them and he didn't let me down.

    Happy to see they are good batteries, even though they, as usual overpromise on the package with unreasonable discharge values. For my uses I'll barely if ever reach its limits (as tested by Mooch). Good.

    And thanks once more to Mooch for his invaluable service to the worldwide vaping community.
     
    MikeyConti, Mooch and Foggy Road like this.
  6. Mooch

    Mooch Electron Wrangler Verified Member ECF Veteran

    Supporting member
    May 13, 2015
    I can't provide any more details but those authenticity code systems aren't nearly as secure as you would hope.
     
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  7. gorman

    gorman Super Member Verified Member ECF Veteran

    Jul 19, 2011
    Milan, Italy
    That's kind of scary. There really isn't a solution to this, then, is there? :(
     
  8. sonicbomb

    sonicbomb Vaping Master Verified Member ECF Veteran

    Feb 17, 2015
    1187 Hunterwasser
    The concept of an authenticity system on Efests is fundamentally comical.
     
    KenD, Mooch and sawlight like this.

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