Aspire 20A 2500mAh ICR 18650 Bench Test Results...only a 15A battery

[Mooch]

These cells were purchased for the purposes of testing with donations made for that purpose. 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.


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 continuously.




Bottom Line
This is only a 15A continuous, 2500mAh ICR battery. It was damaged when discharged at its 20A continuous rating. While it does hold its voltage steady during most of the discharge it dips very low until the battery heats up.


Continuous-Current Test Results



Pulsed-Current Test Results
These tests are done to show the performance of the cell at higher pulsed current levels. If you are running your mod at these levels be aware that you risk overheating, and possibly venting, the battery if there is a malfunction or accidental pressing of your mechanical mod's button.



Comments

• At 10A continuous it reached about 2250mAh. This is average performance for a 2500mAh-rated cell operating at 10A so I am rating this cell at 2500mAh.
• At 15A continuous the temperature rose to 78°C. This is the average temperature for a cell operating at its CDR, an indication that this discharge rate is the CDR for the cell.
• At 20A continuous the temperature rose to 90°C. This is much too high a temperature for a cell operating at its CDR. The voltage is sagging quit badly at the start now too, indicating that the cell is being operated at beyond its rating.
• Two more discharges at 20A continuous showed that damage was being done to the cell (increased voltage sag). This is clearly not a 20A cell.
• At 25A continuous the temperature rose to 107°C, exceeding my 100°C safety limit. The voltage at the start is quite severe at this discharge level.
• I am setting a CDR of 15A for this cell since at this current level the operating temperature is at the average for a cell operating at its CDR. While operating any cell near its rated maximum current level causes damage to the cell, I would expect decent cycle life from this cell at 15A 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. One chart shows the entire discharge at each level. The other chart is zoomed in to show the first 5 minutes to make it easier to see the voltage sag at different current levels.

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

 

[sig-cmt]

It was damaged when discharged at its 20A continuous rating.

Another one bites the dust.