Tested at 10A-38A constant current. Cells were graciously donated for testing by Liion Wholesale (Liion Wholesale Batteries). To prevent any confusion with the eGo-type "batteries", I use the term "cell" here to refer to a single 18650, 26650, etc.
Dropbox - efest 38a 2100mah 18650 wrap.jpeg
Dropbox - efest 38a 2100mah 18650 can.jpeg
Dropbox - efest 38a 2100mah 18650 top.jpeg
Dropbox - efest 38a 2100mah 18650 bottom.jpeg
Disclaimer
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 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.
Bottom Line
This is only a 20A continuous discharge current (CDR) cell. At above 20A its voltage sags very low. At 30A or higher the cell is damaged by each discharge.
Test Results
Dropbox - efest 38a 2100mah 18650 constant-current tests.bmp
Comments
Dropbox - efest 38a 2100mah 18650 wrap.jpeg
Dropbox - efest 38a 2100mah 18650 can.jpeg
Dropbox - efest 38a 2100mah 18650 top.jpeg
Dropbox - efest 38a 2100mah 18650 bottom.jpeg
Disclaimer
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 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.
Bottom Line
This is only a 20A continuous discharge current (CDR) cell. At above 20A its voltage sags very low. At 30A or higher the cell is damaged by each discharge.
Test Results
Dropbox - efest 38a 2100mah 18650 constant-current tests.bmp
Comments
- Discharges at 10A and 15A showed OK capacity.
- At 20A, down to 3.2V, this cell has only 70% of the capacity of the Samsung 25R. The temperature at 20A was moderate.
- At 25A and 30A the voltage sagged considerably and the temperature rose to 85°C and 98°C, respectively. This is clearly a 20A cell.
- At 35A and 38A the voltage is so low that the cell is essentially useless.
- Five additional cycles at 30A started showing signs of damage caused by the high temperature, further emphasizing that the cell has a rating considerably lower than 30A.
- While operating any cell at its rated maximum current causes damage to the cell, I would expect decent cycle life from the Efest 38A 2100mAh cell at 20A due to the moderate temperature at that current level.
- See my blog for more information on the testing procedures, equipment used, and links to all my test results.
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