XTAR XTVTC4 25A 2200mAh 18650 Bench Test Results...it's not a VTC4!

[Mooch]

These cells were purchased by me directly from xtar for the purposes of testing. 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
In spite of its XTVTC4 model number this xtar is not a VTC4. It is a poor performing 20A cell with a 2400mAh capacity rating. It performs a lot worse than the HE2, HE4, or 25R. Even the lower capacity VTC4 lasts longer down to 3.2V and the VTC4 runs at a significantly higher voltage too.

The printing on the cell's case identifies it as a Dishy battery (Hongkong Disheng Ua International Group LTD., www.dishy-battery.com) which appears to have been made in 2014. That is old enough to have affected the cell's performance.

At its 25A rating the voltage quickly dropped below 3.1V and the temperature rose to 97°C, a ridiculously high temperature for a battery running at its claimed rating. I am giving this cell a continuous rating of 20A.

The 18650 ratings table has been updated to include this cell.


Continuous-Current Test Results



Pulsed-Current Test Results



XTAR web site description of this cell



Comments

• At 10A continuous it reached 2214mAh. This is way too high for a 2200mAh cell at 10A but average for a 2400mAh cell so I am rating this cell at 2400mAh.
• At 10A continuous the temperature rose to 52°C. This is significantly below the average temperature of a high-capacity cell running at its continuous discharge rating (CDR).
• At 15A continuous the temperature rose to 69°C. This is below the average temperature of a high-capacity cell running at its CDR.
• At 20A continuous the temperature rose to 81°C. This is just above the average temperature of a cell running at its CDR and an indication that we are near the cell's true rating. There is already a decent amount of extra voltage sag at the start of the discharge.
• At 25A continuous the temperature rose to 97°C. This is a ridiculously high temperature and an indication that we are significantly above the cell's true rating. There is a considerable amount of extra voltage sag at the start.
• I am setting a CDR of 20A 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 20A 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
18350/18500 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

 

[Assi]

Thanks Mooch. I think Xtar should concetrate on what they can do the best - Chargers