Bench Test Results: Vapcell Purple 24A 3750mA 21700...conservatively rated, seems same as Golisi S35

These tests below only note the estimated ratings for these batteries at the time I tested them. Any battery that is not a genuine Samsung, Sony, LG, Panasonic, or Sanyo can change at any time! This is one of the hazards of using “rewrapped” or batteries from other manufacturers so carefully research any battery you are considering using before purchasing.

Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of personal injury or property damage. They are not meant to be used outside of a protected battery pack. Never exceed the battery’s current rating and keep the plastic wrap and top insulating ring in perfect condition.

Testing batteries at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved, understands the risks, has the proper equipment, and takes all appropriate safety precautions.

If the battery has only one current rating number, or if it only says "max", then I have to assume the battery is rated at that current level for any type of discharge, including continuous.




Bottom Line
This cell runs a bit cooler at its 24A rating than other 21700’s at their ratings and appears to be the same China-manufactured cell as the “40A” 3750mAh S35 from Golisi that I rated at 30A. Seems that Vapcell has decided to rate this cell conservatively. I applaud this decision and wish that more companies were willing to do this instead of exaggerating ratings to increase sales.

Our relentless desire for higher current ratings has caused the huge glut of batteries with exaggerated ratings being released as those companies try to tap into our desires. Rating a battery more conservatively not only gives us more realistic expectations for the capabilities of our batteries but increases safety and the overall life of the battery. The battery also operates more efficiently and this wastes less power inside the battery as heat. All good things.

The Vapcells tested out to a lower capacity than the Golisi cells I tested earlier but there isn’t much of a difference down to 3.2V, about the lowest we go. The differences only became really noticeable as the discharge approached my 2.5V testing cutoff voltage.

China-manufactured cells do have more variation in capacity than the ones from Samsung, Sony, LG, and Panasonic/Sanyo so this difference between the Vapcells and Golisi might not be present in all of their cells.

I am rating this cell at 24A and 3500mAh. I won’t recommend using a battery at above the manufacturer’s/wrapper’s rating but this Vapcell runs cooler at its rating than the Golisi does at its 30A rating and they appear to be the same cell.

Two cells were donated for the purposes of testing by Vapcell (www.vapcelltech.com). Thank you!


Continuous Current Discharge Graphs



Ratings Graphic



Performance Specs

• DC Internal Resistance = 19.5mOhms (milliohms) average for the two cells.
• Total energy delivered down to 3.2V at 10A continuous = 10.4Wh (Watt-hours) average
• Total energy delivered down to 3.2V at 20A continuous = 8.5Wh (Watt-hours) average

Comments

• Vapcell paid a fee to be moved to the front of the testing queue, which currently has a 10-12 week backlog. This cannot influence my test results as they pay in advance, have no say about what is in this report, and I don’t care if any company never does this or donates batteries again. My reputation is a lot more important than any battery donation or payment.
• To see how other cells have tested check out this link: https://www.e-cigarette-forum.com/forum/blog-entry/list-of-battery-tests.7436/