Massive fraud on 18650s in the Littokala Aliexpress stores!

leftdisconnected · 2019-10-26T22:36:38.000Z

…or perhaps “100% Samsung Brand New” simply means that they are just as brand new as Samsung cells .

Barkuti · 2019-10-26T23:55:20.000Z

Lightbringer:

I just got an 8pak from FT, all with 3 lobes on the top cap. …

Unlike Bangbad with their button tops and such, FastTech takes care; something quite understandable when you see the money you end up paying there what with one thing and another.

HenrysCat:

…

I am going to be brutally honest here, this is a terrible forum script.

Wellp, conversely I can say that, despite a few hiccups, I find it terrific. :-D

Barkuti · 2019-10-27T01:09:57.000Z

If HenrysCat were to obtain a V(C) curve (voltage to capacity) like the usual ones, it'd be of help. Anyway, let's see if we can make some sort of comparison with the V(t) curves from Henrik:

There are some shape differences like, for example, the nearly instant drop under 4.1V at the start for the non 30Q cell.

BlueSwordM · 2019-10-27T02:14:39.000Z

The problem is that 1A isn’t high enough to see if they are at least acceptable fake 30Qs.

I mean, the top terminal has more than 3 legs, so it’s not a 30Q.

Anyway, could you test the cell at 3A or more, or give any resistance readings?

Thank you.

Lightbringer · 2019-10-27T02:55:57.000Z

Barkuti:

Unlike Bangbad with their button tops and such, FastTech takes care; something quite understandable when you see the money you end up paying there what with one thing and another.

I’m cooking mine now. Can’t get consistent mΩ readings worth a damn, but then again I never could. The Ope isn’t getting heat-stroke — yet — charging and discharging at 1A each (all 4 bays loaded), so I should get some indication by tomorrow.

I typically get a consistent 30xxmAH with 30Qs.

HenrysCat · 2019-10-27T20:23:48.000Z

Barkuti:

If HenrysCat were to obtain a V(C) curve (voltage to capacity) like the usual ones, it'd be of help.

You mean this? That's the only other way the software will display the results.

Currently running a 5A test, will post results when done.

HenrysCat · 2019-10-27T21:51:21.000Z

The results are in :)

Barkuti · 2019-10-27T21:57:18.000Z

HenrysCat:

…

You mean this? That's the only other way the software will display the results.

Currently running a 5A test, will post results when done.

Yes.

Took a look at HKJ's comparator and unsurprisingly couldn't find any match among famous manufacturer cells. Henrik has not tested all the cells which exist, of course, but given the cost and origin the cell must be manufactured by some decent chinese OEM.

Now what matters is, how good that cell actually is? We'll be waiting for the 5A test, if you are using a 4-wire battery holder the cell's internal resistance will be easily inferred with decent precision by comparing the available V(C) curves.

HenrysCat · 2019-10-27T22:04:39.000Z

Barkuti:

We'll be waiting for the 5A test, if you are using a 4-wire battery holder the cell's internal resistance will be easily inferred with decent precision by comparing the available V(C) curves.

5 & 3A test posted above ;)

Barkuti · 2019-10-28T00:06:33.000Z

HenrysCat:

The results are in :)

…

Wellp, it certainly is no high discharge cell (this or your testing setup is terribly flawed). At the 300mA point there's more than 0.3V of difference between the 5A and the 1A curves, it translates in above 75mΩ of internal resistance and this means your setup must not have independent voltage :???: monitoring, and also the cell looks to be of pretty standard 2C discharge rate.

Sun, 10/27/2019 - 23:10

BlueSwordM · 2019-10-28T01:25:05.000Z

Oh yeah.

Average voltage is too low for a 30Q.

An internal resistance measurement+ a 10A test would seal the deal.

HenrysCat · 2019-10-28T06:40:08.000Z

Barkuti:

Wellp, it certainly is no high discharge cell (this or your testing setup is terribly flawed). At the 300mA point there's more than 0.3V of difference between the 5A and the 1A curves, it translates in above 75mΩ of internal resistance and this means your setup must not have independent voltage :???: monitoring, and also the cell looks to be of pretty standard 2C discharge rate.

Thanks Barkuti, it's nice learn something new, my load tester is probably not the best ever, but neither are my cells I guess :)

I will try the same tests on my Sofirn 18650's now.

BlueSwordM:

Oh yeah. Average voltage is too low for a 30Q. An internal resistance measurement+ a 10A test would seal the deal.

Unfortunately 5A is my little testers max.

mattlward · 2019-10-28T13:14:56.000Z

I do not have fancy discharge testing gear. For me, I drop a cell into a known light and use a large gauge current loop and voltage monitor and cook the cell in something that draws like mad. Look for sag and current draw response.

BlueSwordM · 2019-10-28T13:44:08.000Z

What are you talking about?

This is not fancy: Massive post on where to get lithium-ion batteries everywhere in the world! Look at Post 2-5 for info, And Canada Post 123 - #53 by BlueSwordM

mattlward · 2019-10-28T14:02:31.000Z

BlueSwordM:

What are you talking about?

This is not fancy: Massive post on where to get lithium-ion batteries everywhere in the world! Look at Post 2-5 for info, And Canada Post 123 - #53 by BlueSwordM

What is the active load? Model number. Also, could you post a pic of the homemade cell holder? 3 amps is a good enough test for me. I would like to be able to rate cells when I get them and they every 6 months to a year later do the same test again. I use a few multi-cell serial and parallel lights and would like to match them at something higher than 1 amp.

HenrysCat · 2019-10-28T15:01:51.000Z

Just in case anyone was wondering this is what I use :)

https://www.aliexpress.com/item/32614219909.html

&

https://www.aliexpress.com/item/32664964301.html

Would love to know how good it actually is.

Barkuti · 2019-10-28T14:46:49.000Z

HenrysCat:

…

Thanks Barkuti, it's nice learn something new, my load tester is probably not the best ever, but neither are my cells I guess :)

…

Would you mind sharing what tester? I have this discharge tester in my wishlist (some feedback here), may buy it some time. But if I can find some cheap graphic rendering device, the better.

Barkuti · 2019-10-28T14:59:24.000Z

HenrysCat:

Just in case anyone was wondering this is what I use :)

https://www.aliexpress.com/item/32614219909.html

&

https://www.aliexpress.com/item/32664964301.html

Would love to know how goos it actually is.

Aaah, then you have a 4-wire battery holder. Well, this confirms your “3000mAh” cell is a battery of pretty standard discharge. The following is what likely it is:

Source: https://www.alibaba.com/product-detail/High-Capacity-INR18650-3200mAh-Dlg-3_60805797151.html :-)

HenrysCat · 2019-10-28T15:04:52.000Z

Ordered one of these just for the fun of it, looks interesting.

https://www.aliexpress.com/item/4000144172951.html

Think we getting OT here :)

mattlward · 2019-10-28T15:09:07.000Z

HenrysCat:

Just in case anyone was wondering this is what I use

https://www.aliexpress.com/item/32614219909.html

&

https://www.aliexpress.com/item/32664964301.html

Would love to know how good it actually is.

Does their software do English?