ESYB Green 12A 3500mAh 18650 Bench Test Results...tested 10A/3300mAh, seems to be NCR18650GA

[Mooch]

These cells were donated by ESYB 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 18350, 18650, 26650, etc.

While the test results are hard data, the conclusions and recommendations I make based on these tests are only my personal opinion based on my criteria for setting a rating. Carefully research any cell 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.

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 continuously.




Bottom Line
This ESYB cell looks and performs identically to a 10A/3300mAh Panasonic NCR18650GA, even down to the laser-etched characters on the bottom. This cell does not meet its 3500mAh rating though. It has the useless "pulse" rating in larger lettering on the wrap but does list both the continuous and "pulse" current ratings, a very welcome change that's been appearing on some cells lately.


Continuous-Current Test Results



Pulsed-Current Test Results



Comments

• At 5A continuous it reached about 3100mAh. This is too low for a 3500mAh cell at 5A so I am rating this cell at 3300mAh.
• At 10A continuous the temperature rose to 69°C. This is a few degrees below the average temperature for a cell operating at its continuous discharge rating (CDR).
• At 15A continuous the temperature rose to 95°C. This is a ridiculously high temperature and indicates that we're operating above the cell's CDR.
• I am setting a CDR of 12A for this cell. Operating at that level would bring the temperature up to the average for a cell operating at its CDR. While operating any cell near its rated maximum current level causes damage, I would expect decent cycle life from this cell at 12A continuous.
• I have included pulsed discharges but I haven't set pass/fail standards for pulse testing yet. The discharges were done at 5sec on/30sec off, down to 2.5V.

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