I’d have to go dig up receipts but it would have been a US supplier…probably Illumn but maybe Liion Wholesale. They’ve been good cells. Not getting as much use over the last year since I converted most of my 26650 lights to the Queen Battery 26800 cells.
The Vapcell red 26650 5500mah tested the same as the Shockli 5500mah. They were the best 26650 in existence. Unfortunately manufacturers stopped making 26650 flashlights few years ago since 21700 cells came out. If we get a super good 26650, that would convince flashlight manufacturers and maybe other device manufacturers to start making 26650 products again.
Thrunite Catapult V6 and Lumintop ODL20C V2 also new 26650 releases. Looks like Lumintop went with 26800 for the new D3, though.
26800 is where it’s at for fat cells. It offers more than any 26650, still, although it sounds like this new 26650 may be a great general purpose choice with more capacity for replacing cells or in lights that can’t (or don’t wanna be) upgraded with longer tubes or adapters. For new lights, it makes the most sense to go with 21700 or 26800 though. In the nonflashlight world there are still plenty of devices that were designed for 26650 (and cheapie flashlights, too) so they’ll need good cells as well.
I would like to report having self-discharge and overdischarge issue with possibly some Vapcell K62 26650 batteries, based on my purchase of 8 pieces of them.
I purchased 8 pieces of these Vapcell K62 2600mAh 26650 from a local reseller.
All of them arrived properly sealed/shrink-wrapped.
I reported the discharged batteries to the local reseller, and the local reseller asked if I can use reactivation charger to charge the 2 pieces over-discharged batteries.
I was able to charge the 2 over-discharged Vapcell K62 (monitoring the batteries temperature when they were nearly fully charged)
(For the 6 pieces batteries (3.78v and 3.66v), I left them as is and did not try to charge them yet — I plan to observe if their voltages may continue to drop.)
Now for the 2 pieces, after I “reactivated” the over-discharged batteries, I did a round of capacity testing (charge to 4.20v, discharge at 1Amp to 2.50v), and the results are 6208mAh and 6057mAh
After finish charging, I did not use the batteries but left them unused on the table at room temperature (room temperature here is probably around 30 degrees Celsius)
very fast self discharge for one of the over-discharged batteries:
tested voltage (a few hours after charging) … 4.125v
32 hours later … 3.849v
another 14 hours later … 3.66v
from 4.12v self-discharge to 3.66v in around 2 days.
~
for the other over-discharged battery, it appeared to be a bit better:
a few hours after charging … 4.170v
32 hours later … 4.159v
another 17 hours later … 4.151v
(I think this may still be considered normal? will observe a few more days)
Both Sony and Samsung have literature which says: below 1.0V, do not recharge. (lithium ion chemistries)
Cells which self discharge like this are bad cells. Some companies do charge / rest / test cycles and discard the ones with high self discharge rates because those are bad. Apparently Vapcell’s supplier is not doing this.
This matches my experience as well. Out of 3 cells received, only one seems to have stabilized in voltage at around 4.14v. The other two are self discharging at varying degrees. Only one has been used in an actual load, and that on falls under 4v within a week of sitting on the shelf in a well air conditioned room. I will update this with current voltage drops shortly.
Edit: big shout out to 18650batterystore here. I reported the issue to them and they sent me 2 replacement cells for the one defective cell I reported. One of these cells shows high self discharge, although lower than the first cell, and the other seems to be ok.
Edit 2:
Cell 1 - the “bad” cell:
8/09/2022 - 4.136v
8/22/2022 - 3.388v
Cell 2 - replacement cell (capacity tested at 5943mAh on an xtar VC8):
Hi, Jon here from Liion Wholesale. We tested the rest of our stock and found 5/91 to be below 1V. The rest were within 0.02V of when we last quality tested them in June. So it seems there is a small percentage that have excessive self discharge (and they were all next to each other in the box) but the rest are completely fine.
I’m not sure if we’ll reorder these but at least for the moment the rest of our stock should be good to go.
Old thread, but I wanted to report that after about a year’s worth of use and ~80 cycles, 8 of the 12 K62s I have developed high self discharge and high IR. Cells now take 7+ hours to charge at 2A and will discharge down to 3.5v in about 24-36 hours.
I’m disposing of the entire dozen at a recycling center and replacing them with G53s which have held up great.
(For reference, some are from LiionWholesale and some are from Illumn.)