These cells were donated for the purposes of testing. 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 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. 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.
I



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 batteries 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 10A cell. Its appearance and performance are identical to the 10A LG MJ1. Its temperature rose to 104°C/219°F at only 15A! Testing was aborted after doing the first 15A discharges. To rate this battery at 40A is truly shameful behavior by Basen. Imren and Efest did the same thing with their high capacity cells.
15A Basen vs MJ1 Continuous-Current Test Results
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 Safety Grades -- Picking a Safe Battery to Vape With | E-Cigarette Forum
26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum
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 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. 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.
I




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 batteries 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 10A cell. Its appearance and performance are identical to the 10A LG MJ1. Its temperature rose to 104°C/219°F at only 15A! Testing was aborted after doing the first 15A discharges. To rate this battery at 40A is truly shameful behavior by Basen. Imren and Efest did the same thing with their high capacity cells.
15A Basen vs MJ1 Continuous-Current Test Results

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 Safety Grades -- Picking a Safe Battery to Vape With | E-Cigarette Forum
26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum