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Bench Test Results: Hohm Tech Hohm Run XL 30.3A 4007mAh 21700...slightly overrated, good performer

Discussion in 'Batteries and Chargers' started by Mooch, Dec 5, 2019.

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  1. Mooch

    Mooch Electron Wrangler Verified Member ECF Veteran

    Supporting member
    May 13, 2015
    These tests below only note the ESTIMATED ratings for these batteries at the time I tested them. Any battery that is not a genuine Samsung, Sony, Murata, LG, Panasonic, Molicel, or Sanyo can change at any time! This is one of the hazards of using “rewrapped” or batteries from other manufacturers so carefully research any battery you are considering using before purchasing.

    Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage. They are not meant to be used outside of a physically and electrically protected battery pack. Never exceed the battery’s current rating and keep the plastic wrap and top insulating ring in perfect condition. Use of any of these batteries is AT YOUR OWN RISK.

    Testing batteries at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved, understands the risks, has the proper equipment, and takes all appropriate safety precautions.

    If the battery has only one current rating number, or if it only says "max", then I have to assume the battery is rated at that current level for any type of discharge, including continuous.

    4C2A5E4A-FB28-4009-9B01-A2E754D4D8EB.jpeg 5EFD5E0A-DD0B-43D9-B815-40C582E05E3C.jpeg 5A095D34-B0B4-458F-A445-84ED0BB1CCCE.jpeg


    Bottom Line
    This is a good performing 21700 cell that has a slightly exaggerated capacity rating. It performs about the same as the Samsung 40T but not as good as the Molicel P42A.

    The capacities for the three Hohm Run XL (not Hohm Run) cells I tested ranged from 3984mAh to 4035mAh at 800mA (0.2C) down to 2.5V. This is pretty good consistency but one cell failed to meet its 4007mAh rating and the others were very close to the rating. I like to see cells test out at least 100mAh above their rating to ensure no cell, due to normal cell-to-cell inconsistencies, can be below the rating. I am rating this cell at 3900mAh.

    The three cells reached 79°C-81°C at 30A. In my opinion this is close enough to Hohm Tech’s 80°C max rating to give these cells a 30A rating. I prefer a cell to run at a few degrees below the max rated temperature at their rated current level though, to ensure that normal cell-to-cell differences never cause a cell to go over the rated temperature.

    Hohm Tech gives these cells a “temperature limited” rating of 38.6A. This means you could run this cell at 38.6A as long as you do not let it get hotter than 80°C. But I recommend not going that high as it increases your risks, reduces performance, and speeds up the aging of the cell.

    This cell has Hohm Tech’s new wattage-based ratings. It is rated at 87W continuous and has a 111W temperature-limited “max” rating. As long as you don’t let the cell reach 80°C Hohm Tech says you can run it at 111W. They do say this reduces the life of the cell though and I agree. To reduce risk, extend overall cell life, and increase performance I recommend not going over about 25A or 75W. All cells are stressed when you run them near or above their ratings so this is not a recommendation just for the Hohm Run XL cell.

    The new wattage-based ratings system, when fully implemented, could make things easier for new vapers to choose the Hohm Tech cell that best fits the way they vape. But it means they might not learn about current ratings and other things they will need to know if they use any other company’s batteries. I’m torn as to whether it is a good idea or not. I look forward to seeing how the community reacts to it.

    Some of the ratings on the wrap are still printed quite small over a patterned background. This makes them hard to read, reducing their usefulness to vapers.

    493155C8-56B1-4C7C-9990-EF80F94A8BF5.jpeg 3FA472D6-9293-49B7-906E-A7EF7FC26A9F.jpeg

    Hohm Tech (www.hohmtech.com) donated cells for testing, thank you!


    Continuous Current Discharge Graphs
    E0F3AD51-2992-405B-A1FB-CFA3B0F8A39F.jpeg 0D61748B-D4AE-45EC-B752-E64DD34A3F30.jpeg


    Ratings Graphic
    46A9313E-029B-43CB-8B3C-3510A2C7D01D.jpeg



    Performance Specs
    • DC Internal Resistance = 12.9mOhms*** (milliohms) average for the three cells.
    • Watt-hours (energy) delivered at 10A down to 3.2V = 10.7Wh
    • Watt-hours (energy) delivered at 20A down to 3.2V = 9.7Wh
    • Watt-hours (energy) delivered at 30A down to 3.2V = 7.6Wh
    I want to work for the vaping community full time! If you feel what I do is worth a couple dollars a month and you would like early access to battery availability, battery and charger testing and news, and a say in what I test, then please consider becoming a patron and supporting my testing efforts: Battery Mooch is creating battery tests and educating vapers | Patreon.

    To see how other cells have tested check out this link: List of Battery Tests | E-Cigarette Forum

    ***I have switched test jigs, resulting in slightly lower IR readings versus my previous setup. Add 1.6mOhms to this IR value in order to compare these cells to others tested previously.
     

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