Rip-off of a scam 18650

[BurningTantalum]

A friend (non-electrical) delivered some 18650 cells today "for you to check". Ah, they saw you coming, these are hopeless scams, I tittered... but wait, where are my reading glasses... this doesn't say 'UltraFire', it says 'Uitraflrc'. Oh, well at least they are 6800mAHr...
One would think that the pathetic rip-off merchant would at least shrink on a green sleeve and label them 'Panasonic'.
BT

[SiliconWizard]

Their inner construction may be a bad surprise as well.

[Kjelt]

UltraFuc* 

[AVGresponding]

I think I'd rather find them full of sand, rather than reclaimed and likely unstable old Li-whatever...

[ataradov]

Wow, if you are going to copy stuff, why would you pick UltraFire?

[Refrigerator]

Wow, if you are going to copy stuff, why would you pick UltraFire?

My grandpa actually has a genuine UltraFire 18650 battery and i do mean genuine. Even has the nifty protection PCB.
Probably worth it's weight in gold by now, considering how rare they are.

[SiliconWizard]

I think I'd rather find them full of sand, rather than reclaimed and likely unstable old Li-whatever...

My bet is that's it's likely a combination of both.

[BurningTantalum]

Blueskull: That's interesting; I was not aware of the SurFire brand.
Just for info the 'UitrFlrc' cells were charged and then discharged to 3V at around 300mA. The capacity of one, using that test, came out at 65mAhr. The other was 120mAhr.
I assume that they were better than that as new! They were purchased last year and have been in a rarely used torch, I am told.
The cells have a built in disk BMS that makes the length around 68mm and a very tight fit in a battery case.

[Whales]

Could be worse.

[amyk]

I believe UltraFire is actually a clone of TrustFire, which do have good cells.

Blueskull: That's interesting; I was not aware of the SurFire brand.
Just for info the 'UitrFlrc' cells were charged and then discharged to 3V at around 300mA. The capacity of one, using that test, came out at 65mAhr. The other was 120mAhr.
I assume that they were better than that as new! They were purchased last year and have been in a rarely used torch, I am told.
The cells have a built in disk BMS that makes the length around 68mm and a very tight fit in a battery case.

How much do they weigh? Typical 18650 are over 40g, and closer to 50g for the high capacity ones. <200mAh is unusual even for a fake, as those are in the 500mAh range; it might be either a very well-used cell or one that has the seal breached and the electrolyte mostly dried out.

http://danyk.cz/test18650_en.html

[BurningTantalum]

Whales - Well, I recall that storage batteries were originally called 'piles'...  Oooh, nurse!

[BurningTantalum]

Amyk - 25g (including the bms pcb !)
I am charging them both again for another test but after that I will salvage the BMS pcbs and cut up the cells for examination.
BT

[BurningTantalum]

The second test gave a slightly worse capacity so I cut one up. I was mistaken as there was not a BMS fitted, and the width of the active part of the rolled electrodes was 35mm; I don't know how this compares to a genuine capacity cell. The unrolled length was around 400mm.
BT

[BurningTantalum]

One thing that just occurred to me: How is the -ve connection to the cell case usually effected. The +ve end had a tape from one electrode that was soldered to the 'button', but the guts just slid easily out by pushing with a pen so it must simply rely on contact. The roll was a very loose fit in the case, and now that I have unrolled it I can no longer see if part of the electrode was not insulated by the polyethylene (?) wrap.
BT

[Whales]

A lot of cheap 18650s are good "genuine" models, just old one that have already been used (and possibly then re-labelled to look all the same).  It's entirely possible that your roll is genuine materials and dimensions, but (eg) 7 or so years old.

[drussell]

A lot of cheap 18650s are good "genuine" models, just old one that have already been used (and possibly then re-labelled to look all the same).  It's entirely possible that your roll is genuine materials and dimensions, but (eg) 7 or so years old.

That was my first guess when I saw the abysmal capacity test figures....

Probably were originally "real" cells of some sort or another but already have all the life used out of them.    They were likely just re-sleeved and re-marked as some random cells and resold.  Who knows what they were actually, originally.

This is very common with these "discount" cells.   

Just like with the cheap fake-sized USB flash drives, the sellers are usually just hoping you get enough use out of them before you realize that they're used cells with little remaining capacity and lifespan, or you to realize that your "1TB" flash drive actually only contains 256MB of flash and that all those files you thought you wrote just spilled some phantom ones and zeroes off into the ether because there's not actually any flash there for the electrons to go to.  They just want enough time so that they can already be long gone.

[amyk]

The 25g weight alone would indicate it's a purposely manufactured very low capacity cell, and unlikely to be a used one.

You mention the roll was very loose in the case, which is another indication of that.

https://lygte-info.dk/review/batteries2012/UltraFire%20SZ18650%209900mAh%20(Yellow)%20UK.html
https://lygte-info.dk/info/batteryDisassembly9900mAh%20UK.html

[Gregg]

Big Clive took apart a genuine 18650 cell some time ago.  The video might be a good reference as to cell construction.

[drussell]

The 25g weight alone would indicate it's a purposely manufactured very low capacity cell, and unlikely to be a used one.

Not all "real" 18650s are 2Ah+ models, there are some that are actually legit yet not super high capacity, although I do agree that it does make it more likely that they're fake than if they're really heavy and fully "stuffed" but show poor capacity, in which case they are even more likely to be used "legit" cells, but there's a whole range of scam crap out there, of course....

[wraper]

The 25g weight alone would indicate it's a purposely manufactured very low capacity cell, and unlikely to be a used one.

Not all "real" 18650s are 2Ah+ models, there are some that are actually legit yet not super high capacity, although I do agree that it does make it more likely that they're fake than if they're really heavy and fully "stuffed" but show poor capacity, in which case they are even more likely to be used "legit" cells, but there's a whole range of scam crap out there, of course....

1200 mAh is about as low as "legit" cells with true stated capacity go and even they probably are recycled trash. 25g junk usually has about 500 mAh, and there a few turns inside at most.

[amyk]

<2Ah are usually high-rate cells (low capacity high current), and those don't weigh anywhere near as light as 25g either:

https://lygte-info.dk/review/batteries2012/Sanyo%20UR18650SA%201200mAh%20(Red)%20UK.html

https://lygte-info.dk/review/batteries2012/Samsung%20INR18650-13BM%201300mAh%20(Pink)%20UK.html

https://lygte-info.dk/review/batteries2012/LG%2018650%20HA4%201300mAh%20%28Purple%29%20UK.html

All of those are over 40g. The capacity is lower but the electrode foils are thicker to withstand the higher current, making up for the weight difference.