VRK 20A 3000mAh 18650 Bench Test Results...accurately rated, looks like HG2

[Mooch]

These cells were donated for the purposes of testing by Xiamen VRK Technology Co. Ltd. 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 VRK cell is accurately rated at 20A and 3000mAh. It has a useless 30A "pulse" rating in large lettering on the wrap but does list both the continuous and pulse ratings, a very good thing to see. This cell looks identical to the LG HG2 but performs just a touch worse than my "reference" HG2 from a few months ago. It performs a bit better than the HG2's I've tested recently though.


Continuous-Current Test Results



Pulsed-Current Test Results



Comments

• At 10A continuous it reached about 2730mAh. This is a bit below average performance for a 3000mAh cell at 10A bit still within limits so I am rating this cell at 3000mAh.
• At 15A continuous the temperature rose to 73°C. This is a few degrees below the average temperature of a cell running at its continuous discharge rating (CDR).
• At 20A continuous the temperature rose to 83°C. This is above the average temperature of a cell running at its CDR and just a degree above the limits for 20A to be the CDR.
• At 25A continuous the temperature rose to 98°C. This is way above the average temperature of a cell running at its CDR and is an indication that we're above the cell's true rating.
• At 30A continuous the temperature rose to 114°C. This is way above my safety limit of 100°C and indicates that it is too risky to run this battery at its 30A "pulse" rating. If there was a mod malfunction or accidental button press which discharged this cell continuously it could reach a temperature high enough to possibly vent (not go into thermal runaway though).
• I am setting a CDR of 20A for this cell. While technically it should get a 19A CDR the ambient temperature was at the upper end of the acceptable range, 21°C-27°C, so I'm still giving it a 20A rating as it is otherwise an HG2. 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

 

[Baditude]

This cell looks identical to the LG HG2 but performs just a touch worse than my "reference" HG2 from a few months ago. It performs a bit better than the HG2's I've tested recently though.

I wonder why the HG2's you have tested have been inconsistent? Coincidence?

If these are indeed re-wrapped HG2's, their "just a touch worse" performance might be due to being second or third bin batteries. But their better performance than your more recent HG2's is puzzling.

 

[Mooch]

I wonder why the HG2's you have tested have been inconsistent? Coincidence?

If these are indeed re-wrapped HG2's, their "just a touch worse" performance might be due to being second or third bin batteries. But their better performance than your more recent HG2's is puzzling.

There are multiple grades of HG2 floating around; A-1, A-2, A-3, B-1, B-2, B-3. Each is just slightly different from the other and can cause the differences I've been seeing these past few months. I might have been testing A-3 or B-1 cells lately but these are A-2's. Last year I might have tested some A-1's.

We often just get whatever leftovers LG customers sell off as excess inventory so that can result in a wide range of grades. We can't control when they're sold off too and that can result in some being stored for quite a long time before they reach us, affecting their performance.