These cells were donated for testing by ECR member /u/tet5uo and used only for 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.
These are safety-oriented tests, not for performance. Though you can get a lot of performance information from them they are primarily done to check the manufacturer's/rewrapper's ratings and to establish safe continuous discharge limits.
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 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.
Bottom Line
In my opinion, this is a 20A continuous discharge current (CDR) cell with very low capacity for its rating. I only rate it as 2500mAh. I recommend not using it above 20A as it runs at a very high temperature at those current levels. At its 35A continuous rating the voltage instantly plummets and the cell quickly gets very, very hot.
Continuous-Current Test Results
Pulsed-Current Test Results
These pulsed-current tests are only done to show the performance of the cell at its pulse or maximum discharge rating. Do not set your coils or power levels to draw this much current!
Comments
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
These are safety-oriented tests, not for performance. Though you can get a lot of performance information from them they are primarily done to check the manufacturer's/rewrapper's ratings and to establish safe continuous discharge limits.
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 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.
Bottom Line
In my opinion, this is a 20A continuous discharge current (CDR) cell with very low capacity for its rating. I only rate it as 2500mAh. I recommend not using it above 20A as it runs at a very high temperature at those current levels. At its 35A continuous rating the voltage instantly plummets and the cell quickly gets very, very hot.
Continuous-Current Test Results
Pulsed-Current Test Results
These pulsed-current tests are only done to show the performance of the cell at its pulse or maximum discharge rating. Do not set your coils or power levels to draw this much current!
Comments
- At 10A it reached about 2300mAh. This is terrible performance for a 2800mAh-rated cell at 10A. I am giving this cell a capacity rating of 2500mAh.
- At 15A the maximum temperature reached 74°C. This is 4°C below the average temperature of a cell operating at its CDR.
- At 20A the maximum temperature reached 82°C. This is 4°C above the average temperature of a cell operating at its CDR but the same temperature as some LG cells.
- At 25A the temperature rose to 98°C. This is way too hot to set the CDR at 25A.
- A discharge at 30A was not done as it would have resulted in the cell temperature exceeding my 100°C safety limit.
- A discharge at 35A was done to show the performance of the cell at its 35A rating. The voltage dropped immediately to 3.5V and sank down quickly from there.
- Five additional cycles at 20A only showed about the same amount of damage a cell being operated at its CDR for several cycles would show.
- I am setting a CDR of 20A for this cell. It runs a little cool at 15A and matches the temperature of LG cells at 20A. It is most certainly not a 35A cell. While operating any cell near its rated maximum current causes damage to the cell, I would expect good cycle life from this cell at 20A.
- A single pulsed-current discharge at 35A (4 secs on/30 secs off) was done to test the cell at its rating. The first pulse dropped the voltage down to about 3.35V. Its temperature rose to 59°C max before the voltage eventually dropped to 2.50V.
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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