HohmWork 40.6A 2531mAh 18650 Bench Test Results...only a 20A battery but great, better than HE2

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Mooch

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  • May 13, 2015
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    Tested at 10A-40A constant current and 30A-70A 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.

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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, though it is confusingly labeled, it is a great 20A continuous discharge rating (CDR) battery. It runs at higher voltages, and lasts a bit longer down to 3.2V, than the HE2 it's said to be based on. I have not tested the safety improvements that Hohm Tech says have been made to this battery compared to the HE2.


    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


    HohmLife vs HE2 graphs
    image.jpg image.jpg image.jpg


    Comments
    • This cell has a 40.6A rating without any indication on the cell or packaging as to whether that is a continuous or pulse rating. Since many people assume that this means the rating can be used for continuous discharges I have tested these cells at up to 40A continuous.
    • Doing some searching one can find out that the 40.6 A rating is a "pulse" rating and that the CDR is 21.5A. But vapers shouldn't have to search to find the ratings for their cells. In my opinion, if there is a rating on the cell it should be the continuous rating. If the pulse rating is also displayed then the pulse length and rest times should be posted online, if not on the cell.
    • Without knowing the pulse length/rest times for the 40.6A pulse rating for this cell, and what criteria they used to establish the rating (voltage drop? temperature? other?), the pulse rating can't be used for comparing this cell to any other.
    • At 10A it reached about 2300mAh. This is about average performance for a 2531mAh-rated cell at 10A.
    • At 15A the maximum temperature reached 68°C. This is below the average temperature of a cell operating at its continuous discharge rating (CDR).
    • At 20A the maximum temperature reached 79°C. This is just above the average temperature of a cell operating at its continuous discharge rating (CDR), indicating that we're operating at or near the CDR for this cell.
    • At 25A the temperature rose to 91°C. This is way too high for a cell operating at its CDR.
    • At 30A the temperature rose to 102°C. This is way too high for a cell operating at its CDR and is above my 100°C safety limit.
    • A discharge at 35A showed increasing voltage sag and loss of capacity. The temperature rose to 113°C, way above my 100°C safety limit.
    • A discharge at 40A shows the voltage quickly collapsing. This is clearly not a 40.6A cell.
    • Another 20A discharge showed that some damage was done to the cell during the previous higher current discharges. Probably the 35A discharge as the temperature rose above the point where I typically start to see a cell becoming immediately damaged.
    • I am setting a CDR of 20A for this cell. Its temperature at this discharge current level is very close to 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 20A.
    • Its voltages under load were consistently above the HE2's except during the last 25% of the discharge. The HohmWork's voltages dropped quicker at the end due to the HE2's slightly higher capacity overall. However, down to 3.2V the HohmWork cell had higher capacity than the HE2 due to the HohmWork cell's higher voltage under load.
    • 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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    Louis Robbins

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    Jan 12, 2016
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    Possibly, but performance speaks for itself. The market is awash with re-wrappers with labels like the one above.

    Yes it is and as a B&M owner I see it everyday. I only sell LG, Samsung, some Sony and Panasonic. The Homhtech batteries are different. They are listed on the batteries as a 20A but include the pulse rating. As Mooch's test prove they are indeed great performing batteries. Are they the be all end all of 18650s? No but they are a small step to getting a true vaping 18650 battery market exclusive to us vapers.
     
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