I’ve got a few K64 Vapecells coming, U wonder who actually makes them & whether there sold under the original brand.
I received 2 pc K64 last week and one has 3,67v, the other one has 0,3v ... so one is dead on arrival.
I used the good one in D4sV2 and in Ni40 and it is very similar to the Shockli 5500 and I get round about 6000mAh into by a Start of 2,95 to 2,98v. So as my first resume the good one is a good Battery but do not reach more kapacity like the Shockli in the first attempts.
I would like to see, what Vapcell say to the DOA battery, but no answer yet now....
Hhmm, don't think I have a head to head. Should do one.
K64 is not available to order anymore. On TLF I noticed another member reporting that two out of two K64 batteries were dead on arrival with 0.7V and 0.74V.
Ouch! I got 2 good ones - weird.
Got two on order from the Vapcell ali-store, not send-out yet. Let’s see what happens 
Vapcell, can you check my order?
I ordered 1lot(8pcs) Vapcell K64 from Vapcell/AliExpress store last April 3, 2021.
I was given this tracking number, but later changed to another tracking number:
RB635245138TW & RB753931767TW,
but both these tracking numbers do not show any infomation on tracking websites.
Did some simple tests last night, but not long timed testing. Just in initial amps on a FT02S (quad XHP50.2's) w/mods, all cells charged to 4.21V:
Shockli 5500: 22.8A
Vapcell K64: 26.4A
Samsung 40T: 30.5A
Vapcell T50: 31.0A
On a MF01 Mini, brass w/mods:
Vapcell K64: 24.1A
Vapcell T50: 27.2A
On a HK4S (quad SST-40) w/mods:
Vapcell K64: 21.2A
Shockli 5500: 18.0A
So the T50 is much it's superior, but the K64 does well against the Shockli. This is just turn on amps, somewhat indicative of what it can do, but an initial 30 sec test, plus a full timed run would be a better comparison.
After my issue with the Vapcell K30 I’ve been put right off.
120pcs were fine and 39pcs had high self discharge. Charged all 39pcs and after just 5 days some were just 4.12v, a cell from the 120pcs was still sitting at 4.192v.
Very decent performance at a good price so it’s rather disappointing
Has that 40T also been modded 
37.2 amps? :-O Jeez…that one must have become pretty hot within a blink of an eye.
Now, I will regret for the rest of my life that I ordered two pieces of the T50, only. :-D
Crap!! Will update - rushing at work... Those erroneous quotes will live forever! 
Yikes! There seems to be lots of bad cells around lately
Dennis: Please, if you could, explain a bit of what going on with quality as of late? What's the testing process?
I had a sneaking suspicion the K64 would have QC problems. Especially since 1. Vapcell does not own their own factory 2. Nobody else is producing a battery with these specs.
To their credit, it has to be tough to design and manufacture a new high discharge cell with increased capacity.
The F14 doesn’t seem to have the same problems probably because only capacity increased. Probably easier to rework existing technology to increase capacity but not both at the same time (high discharge + increased capacity).
Hopefully the F14 stays around, great for Convoy lights since they can’t pull more than 3A.
I ordered some batteries from Vapcell 101 days ago and still not received…last tracking number update was 47 days ago…
And they still want me to wait 
Fair enough if you chose the cheapest shipping option, maybe chose an alternative for a higher cost
They don’t offer any alternative for me, only $6 option.
Interesting, I had a bunch of Vapecells arrive yesterday 2 of which were K64’s and they were perfectly ‘storage’ charged. 3.76v & 3.84v. I drained one down to 2.8v then charged it and got well over 6k mAh’s like 6250mAh. The vapecelll INR21700 4200mAh cells which are the Mollicel 4200 30A continuous discharge had a clear wrapping over the cells which I thought was clever protecting the contacts. But so far I like those K64 cells and the little 18350’s with 1400mAh tested well (T14), I measured over 1400mah when charging but are only 4A. But to be honest I’ve been pretty happy with Sofirns cells like their 4K/5K 21700 and I have a bunch of their 18650’s which have been decent. Much cheaper too.
Having unequal storage voltage shows there’s still a voltage instability problem. Every single Samsung, Panasonic, Sony, and Molicel have been exactly the same voltage across 500+ cells.
Roughly 40 of the 120pcs Vapcell K30 that were okay in my order were a solid 3.71v, the other 80pcs were 3.68v+, and the remaining were even as low as 1.78v (got a refund on 20pcs of the worst)
I guess the best we can do is:
- Measure internal resistance (requires some equipment to compare between resting voltage and voltage under load) and compare against other batteries of the same make and model and/or against the datasheet (if there was one available).
- Measure internal impedance (requires an impedance meter like Vapcell YR1030/1035 or SM8124A) and compare against other batteries of the same make and model.
- Charge the battery to a certain value (maybe "storage voltage" around 3.6V - 3.8V would be best?) and observe any sagging in resting voltage over the course of let's say 14 days or 30 days. Cells of good quality should keep their voltage rocksolidly stable. Those with a quickly dropping voltage may have some issues concerning their electrodes inside but I can only guess.
- Batteries below a certain resting voltage (IDK, 3.0V or maybe lower than this) should not be charged at all and considered as defective?
I wonder how safe it is to run lithium-ion batteries with a high self-discharge rate. I know that some chemistries have a rather high self-discharge rate but I only saw these in NiCd or NiMH cells before. A lithium-ion battery is a whole different thing, I guess.
BTW, I have (among other batteries) six K64 batteries incoming. They are probably still en route to Europe or being checked by customs (who knows). I will be happy to carry out steps 2 and 3 and report about their status as soon they have arrived.
Do you mean F14? I can’t find a T14
Hopefully Vapcell reworks the K64. I don’t need it but I want it.