Samsung 30Q's voltage sag - fake or real?

[TheRaiden]

Hey everyone and hopefully Mooch

I bought 6x Samsung 30q's from a local B&M to use in my LV Triade 250C and i've been wondering if they are real or fake.

The reason i suspect them to be fake is that the number "3" on the wrapping is not asymmetrical like it is on the pictures of 30q's on sites like illumn and liionwholesale.
The number "3" is curved on the topside. apart from that everything looks legit and also the print quality is very fine and not smudgy.

The B&M claim they purchase the battery's they stock from Nkon.nl

Measured capacity from 2.75v to 4.2v on charger is 2780mah
Voltage sag when fired at 85w in my triple cell 250c measures 0.47v (from 4.18 down to 3.71) on all three battery's. On 100w the sag is 0.55v

So do you think they are fake or real?

 

[Baditude]

Might help to show a close up pic of the lettering and the positive end of the battery. Also, if you wish to alert Mooch for questions use @Mooch .

 

[TheRaiden]

Positive end has the 3 prong samsung layout, my cell camera is fubar and my webcam is horrible, won't pick up details :/

 

[Rossum]

Are you firing one cell at a time at those wattages? If so, I come up with an internal resistance in the high teens of milliohms. That's OK, but not great, and not definitive.

OTOH, if you're splitting that wattage between three cells and getting that much drop, then their internal resistances are up around 50+ milliohms and they're definitely fake.

FWIW, brand-new 30Qs I've measured were just under 13 milliohms, but that was with an AC meter, not DC.

 

[TheRaiden]

Are you firing one cell at a time at those wattages? If so, I come up with an internal resistance in the high teens of milliohms. That's OK, but not great, and not definitive.

OTOH, if you're splitting that wattage between three cells and getting that much drop, then their internal resistances are up around 50+ milliohms and they're definitely fake.

FWIW, brand-new 30Qs I've measured were just under 13 milliohms, but that was with an AC meter, not DC.

Those are 3 cells firing at the same time, same sag with all three

 

[Rossum]

Those are 3 cells firing at the same time, same sag with all three

Well, if you're splitting that 85-100w load between three cells, the voltage drop (from which one can calculate the internal resistance) strikes me as excessive and would lead me to think that the cells are fake.

 

[Mooch]

Hey everyone and hopefully Mooch

I bought 6x Samsung 30q's from a local B&M to use in my LV Triade 250C and i've been wondering if they are real or fake.

The reason i suspect them to be fake is that the number "3" on the wrapping is not asymmetrical like it is on the pictures of 30q's on sites like illumn and liionwholesale.
The number "3" is curved on the topside. apart from that everything looks legit and also the print quality is very fine and not smudgy.

The B&M claim they purchase the battery's they stock from Nkon.nl

Measured capacity from 2.75v to 4.2v on charger is 2780mah
Voltage sag when fired at 85w in my triple cell 250c measures 0.47v (from 4.18 down to 3.71) on all three battery's. On 100w the sag is 0.55v

So do you think they are fake or real?

The quality and style of the wrap printing can vary considerably over time and between factories. I would not put too much stock in that.

The capacity measuring accuracy of the chargers we use can be very poor. If you have a known genuine 30Q you can compare it to yours though. Those results will be consistent enough to see if one might be a lot different than the other. The counterfeiters know that capacity can be easily checked though and often use similar capacity fake cells.

The DC internal resistance (DC IR) is about 22mOhms for new cells of a decent grade. That’s probably around 0.22V battery sag at 100W in a three-battery device with freshly charged cells. But, the voltage you are reading is not the battery voltage. It is the voltage at the pins of the chip after the current flows from the battery, through the contact, the connection to the contact, the wire, the connection to the circuit board, and the circuit board traces to the chip.

There is the total voltage drop to the chip and another total voltage drop from the chip back to the battery that has to be added to that roughly 0.22V battery sag. That could easily be another 0.33V.

But, we still don’t know if that means they are fake or not.

In bright light look through the plastic wrap near the top of the battery. There should be two lines of codes printed on the metal can of the battery.

The second character of the first line of codes for the 30Q must be a zero. All the rest doesn’t matter.

If it is not a zero then the battery is a fake. If there are no codes then it is a fake. If the code is correct then it MIGHT be genuine.

Not much else can be done to see if they might be fake other than higher current testing with temperature measurement and close examination with a magnifier.

 

[TheRaiden]

Thank you for your answer Mooch!
I could see the code through the wrapper and the second character is indeed a zero.
I also got my hands on a multimeter and they measured at 24.6 mOhms.
I did not realise that the voltage sag displayed in Escribe's device monitor was measured at the chip, but of course it is
I also weighted the cells and they came out at 45.8 grams which is within spec according to data sheet.

So they are probably authentic, it was just the number "3" i was mostly suspicious about, but as you say, printing methods may vary between factory's.

Thank you all for chipping in

 

[Rossum]

I also got my hands on a multimeter and they measured at 24.6 mOhms.

Curious: How did you perform this measurement with a multimeter?

 

[Mooch]

Thank you for your answer Mooch!
I could see the code through the wrapper and the second character is indeed a zero.
I also got my hands on a multimeter and they measured at 24.6 mOhms.
I did not realise that the voltage sag displayed in Escribe's device monitor was measured at the chip, but of course it is
I also weighted the cells and they came out at 45.8 grams which is within spec according to data sheet.

So they are probably authentic, it was just the number "3" i was mostly suspicious about, but as you say, printing methods may vary between factory's.

Thank you all for chipping in

Just a quick note...a multimeter can’t be used for measuring internal resistance directly. For DC internal resistance you need to pulse them at two known current levels, measure voltages at both levels, and use Ohm’s Law to calculate the equivalent resistance.

A multimeter’s general resistance measuring accuracy is very poor at under about one ohm too.

 

[ASCC]

Here is some more information on Samsung INR18650-30Q. Website in Russian - use a translator. But the pictures will be clear.