Efest 35A 2800mAh 18650 Bench Test Results...a 20A/2300mAh battery

Status
Not open for further replies.

Mooch

Electron Wrangler
ECF Veteran
Verified Member
  • May 13, 2015
    4,021
    15,921
    Tested at 10A-25A constant current. This cell was purchased by a friend from IMRBatteries and donated for testing. 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 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 selected 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


    Bottom Line
    In my opinion, this is an average 20A continuous discharge current (CDR) cell that runs extremely hot at 25A. Its capacity is much lower than its rating. Its capacity at 20A down to 3.2V is almost 25% less than the 25R's.


    Test Results
    image.jpg


    Comments
    • At 10A the discharge reached a bit under 2000mAh. This is terrible capacity for a 35A-rated cell that's supposed to be 2800mAh. I rate this Efest's capacity as 2300mAh.
    • At 20A the cell had a high maximum temperature of 83°C. This is the highest of what I'll accept for a cell running at its CDR, and only because a couple of Samsung's and LG's do the same.
    • At 20A down to 3.2V its capacity is about 1050mAh, about 25% less than the 25R.
    • At 25A the cell reached a max temperature of 97°C just shy of my 100°C safety cutoff. At 35A this cell would be operating close to a temperature that could cause it to vent. And this is without it being in a closed mod, possibly near a warm 510 connector or another hot cell.
    • An additional five cycles at 20A showed no signs of damage.
    • I am setting a CDR of 20A for this cell. I think you will get decent cycle life at 20A due to the lack of damage seen at that level. In my opinion you should not run this cell above 20A.
    • To see how other batteries have tested and how hard you can safely push them, check out the links in my signature.
     
    Status
    Not open for further replies.

    Users who are viewing this thread