Samsung date codes

[nick779]

@d_t_a

I would like to revisit this.

I’ve previously got a few “Samsung INR18650-30Q” which I suspect were not genuine 30Q. However they look very similar to the real Samsung 30Q, and capacity test seems to be similar (around 2800+mAh, where genuine 30Q have around 2900+mAh on capacity discharge test).

The AC IR (using YR1030 resistance tester) of genuine 30Q appears to be around 11.8mOhms (those marked “141”) and around 12.6mOhms (those marked “136”), at least on the samples of 30Q that I have.

The AC IR (YR1030) of the “non-genuine” 30Q are around 21mOhms, which is far from the ~12mOhms of the genuine 30Q.

On checking the “date” code underneath the wrapper. I notice the genuine 30Q “141” or “136” have something like L0J4 or L0I1.
As per the above decoding information
“2nd digit: Final number of Model Name (“0” is INR18650-30x)”

So they are “0” = 30Q.

But on the non-genuine 30Q, I see that they read “E9G0” or “E9HJ” (G = 2016, H = 2017), but “9” would then refer to ‘final number of model name’, does this mean the Samsung INR18650-29E?

So maybe these non-genuine 30Q are probably real Samsung INR18650-29E instead?

(on a side note: I also checked the underlying code for Samsung 25R, and they have “5” in the 2nd-digit).

Does anyone know what is supposed to be the AC IR (using YR1030 or similar resistance meter) of a genuine Samsung INR18650-29E?

I had something similar happen to me a few weeks ago(Samsung INR18650-30Q Questionable markings from trusted seller.), but I have no reliable/accurate way of testing. I only have a MiBoxer C412. The questionable button top cells have a similar IR to the “known good L0XX” button tops I have in my Q8 from a few years ago.

The questionable cells were bought from Liionwholesale and they claim it was because Samsung had to move production around that the lot/date codes were not consistent last year.