Weird positive pole, no legs, positive pole is aluminum material, not steel.
How do you think?
Do you know where to get one?
I would pay a VERY heavy premium to get myself one of these 21700s and see if they have some massive capacities.
I think it won’t be long before the 21700 will match 26650 specs.
That will signal the end of the not so popular 26650.
More importantly I hope we will see more flashlights for 21700’s
BlueSwordM, why not buy yourself a nice Tesla car (or Powerwall) and rip out a few cells for flashlight use? 
I would like to, but my SO would probably rip me apart.
They aren’t 5000mah.
How do you know they are Tesla cells?
They look a bit like these:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=202315850953
These are advertised as samsung 40T, but the specs don’t match the 40T. I bought a few, but it looks like they are sold out now. The capacity is around 4300mAh, and the IR is around 35 milliOhms (tested using my turnigy reaktor charger which seems to give accurate results). The positive pole is strange as mentioned in the OP; I was planning on soldering to them but I’m not sure I can…
How much do you think the capacity is？
Yeah ,they are tesla cells too,the same cells
but ebay .the batteries have used many circles， our pics show it is new and original packing
But how do you know they are Tesla cells? Where did they come from?
I did a discharge curve of one of the cells. The IR is fairly low at 35 mOhms, but the voltage of the discharge curve was relatively low. I’ll post the curve once I upload it to my computer.
About 4800mAh, +/- 100.
Very similar to the samsung 48G
Tesla is using a slightly different chemistry though, NCA, to save some cost.
You can determine the capacity by finding the Wh per cell using the total vehicle capacity and dividing by the number of cells.
We actually measured the 1A discharge to 2.5V, about 4950-5000mah capacity.
Do you have a specification of this battery
Measure it to 2.8v and see what you get.
Also what are you using to measure it?
My friend at tesla can’t give me official specs but he pretty much confirmed what I know about the capacity and chemistry.
Looks like the seller undercharged for these, 16 3 packs sold in about 2 days. You likely got a really good deal, assuming you can use them.
Well done, this mean no low temp soldering them unless oxygen free atmosphere chamber or… whatever:
I won't. There are much better things to spend my money in with reward me with much higher benefit.
For example: buying a slightly lower spec battery at a (much) lower price.
That doesn't sounds good.
I don't really care about this nor any other hype stuff no matter how good it is.
Cheers ^:)
P.S.: this is not to discourage anyone after them, it is just the way I perceive this.
Originally posted on Fri, 06/08/2018 - 00:19; edited for a typo fixup and final comment.
Thanks you very much,Enderman
We use a battery compartment test ,test 10 samples
Maybe you should send samples to HKJ so he can do proper testing of the cells.
http://budgetlightforum.com/user/1091
Normal indoor environment, use aluminum nickel plate to weld
Welding ≠ soldering.
The way the cell is designed for sure has a lot to do with Tesla's specific assembly needs. Period.
On the other hand, Samsung is demonstrating to be a leader in the small cylindrical cell market. Their top notch products speak for themselves. I really doubt this Panasonic/Tesla cell is going to ding any gongs for us, even with whatever a$$load of help from Tesla.
I ain't got time to bleed… :-D
Cheers ^:)