These cells were purchased for the purposes of testing by me. 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 iJoy cell's 40A rating is exaggerated. This is incredibly frustrating because it's the first 30A 26650 I've ever tested and no exaggeration was needed! Why the hell do companies like iJoy still think they need to do this to sell batteries?
This is the first 26650 I've tested that acts like an 18650. Its internal resistance is lower than many of the good 18650's and it held its voltage well. At 30A/100W pulsed it ran approximately 75% longer, and 0.15V-0.20V higher, than the Basen and Brillipower 4500mAh cells down to 3.2V. It doesn't match the appearance of any other 26650 I have so I don't know where this cell came from.
The 26650 ratings table has been updated to include this cell.
Continuous-Current Test Results
Pulse-Current Test Results
Comments
List of Battery Tests | E-Cigarette Forum
18350/18500 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
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 iJoy cell's 40A rating is exaggerated. This is incredibly frustrating because it's the first 30A 26650 I've ever tested and no exaggeration was needed! Why the hell do companies like iJoy still think they need to do this to sell batteries?
This is the first 26650 I've tested that acts like an 18650. Its internal resistance is lower than many of the good 18650's and it held its voltage well. At 30A/100W pulsed it ran approximately 75% longer, and 0.15V-0.20V higher, than the Basen and Brillipower 4500mAh cells down to 3.2V. It doesn't match the appearance of any other 26650 I have so I don't know where this cell came from.
The 26650 ratings table has been updated to include this cell.
Continuous-Current Test Results
Pulse-Current Test Results
Comments
- At 10A continuous it reached about 4100mAh. This is good performance for a 4200mAh cell at 10A so I am rating this cell at 4200mAh.
- At 15A continuous the temperature rose to 52°C. This is way below the average temperature of a cell operating at its continuous discharge rating (CDR) and is an indication that we are operating way below its true rating.
- At 20A continuous the temperature rose to 59°C. This is still way below the average temperature of a cell operating at its CDR and is an indication that we are operating way below its true rating.
- At 25A continuous the temperature rose to 69°C. This is still below the average temperature of a cell operating at its CDR and is an indication that we are operating below its true rating.
- At 30A continuous the temperature rose to 77°C. This is just below the average temperature of a cell operating at its CDR and is an indication that we are operating at its true rating.
- At 35A continuous the temperature rose to 83°C. This is above the average temperature of a cell operating at its CDR and is an indication that we are operating at above its true rating. The voltage is sagging a lot.
- At 40A continuous the temperature rose to 85°C. This is above the average temperature of a cell operating at its CDR and is an indication that we are operating at above its true rating. The voltage is sagging a huge amount.
- I am setting a CDR of 30A for this cell. 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 30A 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.
List of Battery Tests | E-Cigarette Forum
18350/18500 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
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