Efest Purple 20A 3500mAh 18650 Bench Test Results...just another rewrapped 10A battery

[Mooch]

These cells were purchased by me for the purpose of testing. 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 Efest is a rewrap, identical in appearance and performance to the Panasonic 10A/3300mAh NCR18650GA. Both the Efest's current and capacity ratings are exaggerated. At 20A continuous this cell gets hot enough to boil water, 111°C.

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 of, the battery if there is a malfunction or accidental pressing of your mechanical mod's button.



Efest Purple 20A 3500mAh vs Panasonic NCR18650GA



Comments

• At 10A continuous it reached about 3100mAh. This is average performance for a 3300mAh-rated cell operating at 10A so I am rating this cell at 3300mAh.
• At 10A continuous its temperature rose to 70°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 91°C. This is significantly above the average temperature for a cell operating at its CDR.
• At 20A continuous the temperature rose to 111°C. This is a dangerously high temperature, way above my safety cutoff of 100°C. This is clearly not a 20A battery.
• 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:
https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/
https://www.e-cigarette-forum.com/f...afety-grades-and-pulse-performance-data.7566/
18650 Battery Ratings -- Picking a Safe Battery to Vape With | E-Cigarette Forum
26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum

 

[sonicbomb]

Another epic fail from those worthless gong farmers.

 

[bizzyb0t]

Efest just can't be trusted. Do they just not give a frak about safety?

 

[Scy123]

Wow this is going too far.

 

[jpasint]

Wow this is going too far.

Agreed. Its reviews like this that make me happy that with the wattage that I vape at I'm only drawing about 2 amps of current from my 18650's.

Companies like this are dangerous to the vaping industry.
People could be seriously injured or even killed using this battery at its stated rating.

 

[sig-cmt]

Another epic fail from those worthless gong farmers.

Gong farmer...I learned a new term today

 

[KenD]

Gong farmer...I learned a new term today

Yeah, me too. Should be useful in the future

Sent from my M7_PLUS using Tapatalk

 

[budynbuick]

Wow this is going too far.

Yes. I wonder what with the popularity of these cells, why there have been no reported failures? Or have there? Also,,why has this not been revealed sooner? Must be cause of the perty wrapper lol.

 

[Mooch]

Yes. I wonder what with the popularity of these cells, why there have been no reported failures? Or have there? Also,,why has this not been revealed sooner? Must be cause of the perty wrapper lol.

If a battery dies early most people just toss it and not buy that model again. They're not going to vent unless severely abused and the chance of it going into thermal runaway is almost zero unless short-circuited. And even then it's hard to do.

There aren't a lot testers out there who try to figure out what was rewrapped for these batteries. By the time someone might figure it out that battery has been replaced by a different one.