Latest release Vapcell 21700 5600mah 12.5A battery

I don’t think you can get 6400mAh from regular 26650 cells, no matter how you bin them, so it has to be a new cell. Not all K64 and K31 cells have the self-discharge issues, so it looks like something that can be improved rather than an inherent issue with the cells.

Hello, members of the forum. I’ve been busy recently and didn’t reply to the information in time

Yes. Vapcell k64 battery has the problem of self discharge. At present, vapcell company has stopped selling. We’re already dealing with this battery technology. If you place an order for vapcell k64, you can apply for a refund of the full amount to Ali-express. The customer staff will process the refund request as soon as possible

At present, among the batteries sold in vapcell warehouse, Only k64 receives a large proportion of quality complaints. OOccasionally, we receive a very small proportion of quality complaints, among which some quality problems are also caused by the improper use of consumers,most of the vapcell batteries have no self discharge quality problem. Please don’t worry about the quality problems of all vapcell batteries.

K64 is too fast delivery, delivery detection voltage is normal, did not stand more than a month to test, resulting in quality problem. k64 is a new battery technology of 26650, which needs enough time to test. Last time, there was a customer feedback on the quality of K30 cell, which has been improved. At present, the battery performance is very stable.

K64 battery is still undergoing technical improvement. If it can pass the tests, it will continue to be sold. It is expected to take several months.

Vapcell is committed to developing high-tech battery products. Through these quality problems, we will learn from them and strengthen quality control. let every consumer receive high quality batteries

Thank you for your support to vapcell

Thank you

Ahh, thanks Dennis! I'll apply for the refund.

Guys, what do you do with cells having a considerable self-discharge rate? Safe to keep on using or better put them into the trash?

Well, the way they are acting may not be totally useless, just dunno how safe.

From Mooch’s Facebook

“If you are not sure you have bad K64 cells then charge them fully and let them sit for a day to let their voltages settle. After a day’s rest accurately measure and write down their voltages. Then store them in a non-conductive case at room temperature for at least a week and then re-measure their voltages. If any have dropped by more than a few thousandths of a volt then IMO they are self-discharging too fast and you should get a refund.”

If they’re dropping too quickly I’d bin them, especially since this is a new untested cell

I fear an internal short while charging them up. I just found this on Battery University:

„Li-ion self-discharges about 5 percent in the first 24 hours and then loses 1–2 percent per month; the protection circuit adds another 3 percent per month. A faulty separator can lead to elevated self-discharge that could develop into a current path, generating heat and, in an extreme case, initiate a thermal breakdown.“

Source: https://batteryuniversity.com/learn/article/elevating_self_discharge

Thanks. I guess it’s best to first separate cells with deep discharge state (< 2.5V) from those that still show a reasonable voltage (> 2.5V and < 4.2V). I would say the deep discharged ones should better be disposed right away without any attempts of charging.

Maybe I am interpreting that statement incorrectly, but 5% of 4.20 volts is 0.21 volts and I would be concerned if any of my Li-ion batteries self-discharged to 3.99 volts within 24 hours after being fully charged to 4.20 volts.

Your statement is not accurate. You cant just do 4.2*.05 for charge percent. See our very own HKJ’s write up

In any case settling down 5% from 4.2 for a large battery like this would still be around 4.1x

Thanks for the correction, what I forgot to take into account is realizing that the discharged voltage of Li-ion is ~2.80 volts, therefor:


4.20 volts - 2.80 volts = 1.40 volts
5% of 1.40 volt = 0.07 volts
4.20 volts - 0.07 volts = 4.13 volts


This self-discharge voltage within 24 hours, seems more reasonable.

This goes to show that you shouldn’t rush QC, because QC always takes longer than the rest of the company wants, as they see it as “preventing them from making money”, when its more like “assuring they can make money” off of the product.

Also not right since that implies that at 3V there is still 15% battery left. 2.8+0.07*3 = 3.01V

Most of the capacity comes from the higher voltages and not much left when the battery is low voltage. Either way, it would be nice if some data sheet spec exists per battery to say “expect is to maintain >= this voltage after 1 month, 6 months, 12 months” or similar.

Thanks "contactcr" for increasing my understanding.

I am an older person who worries too much to sleep well at night. Flashlights have given me something to do at night and the little pleasures from collecting and comparing many varieties of these "budget light treasures" keep my mind from dwelling on the larger problems of life.

Researching and learning this technology which is new to me (and having to remember the different user interfaces of each light) also helps keep my mind sharp. I do not post much and wish I had more to contribute, but I do read almost all of the BLF posts daily.

Thanks again to all on this forum.

Also resting voltage is waay different than load voltage.
If a cell has a resting voltage of 3.0v it is 99% dead, as when you apply a load to it, it quickly drops towards 2.5v.
Whereas if you run a constant 1 amp discharge till it hits 3.0v, it may “bounce” back up to 3.3v or higher.
And yes I pulled these numbers out of my butt, but the point still stands.

Yes, and I want it back :expressionless:

Are you listening, Dennis?

Hello, this white 16340 has been out of production for a long time

At present, vapcell 16340 650mah 6A T6 battery has just been launched, which is also white

If there is a demand, you can consider purchasing

Will do, but can’t find it in your AE shop.

Any reason for that, Dennis? The other cell had higher capacity and current! Was there any suply issue or security?

These are poor capacity and dischcharge current so i wouldn’t call them upgrade.

Why going south when old white was the king?

The old version of white battery was customized and researched by vapcell alone in cooperation with the battery factory, but the sales volume was too small for the battery factory to bear, and the factory had to rely on large sales volume to make money

So it has stopped production

The flashlight Market is too small, and the sales of high power batteries are not optimistic

Vapcell 14500 1000mah 10A also encountered such a low sales situation
Hope the future will be better

Vapcell T8 and T6 can meet the needs of high capacity and high power flashlight users

Welcome to purchase :slight_smile: