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Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: May 21 2019 12:14am
by thunderheart
Samsung INR18650-30Q is a high capacity 3000mAh Li-ion cell of 18650 size which supports continuous discharge at up to 15A. It's can be called a high drain cell or even a mid-to-high drain one.
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The battery was bought from my reliable supplier (Queen Battery) and tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.
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I've used version 3.0 of my battery holder based on 0.5mm thick pure copper terminals
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I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle each battery was charged at standard charge current mentioned in its datasheet to charge end voltage. Before each discharging or charging i've held a 1-1.5hrs pause. The environment temperature was 23.0-24.5°C. To be sure in results i've done each test minimum twice (usually 3-4 times).


Samsung INR18650-30Q

My cell has the following marking: INR18650-30Q SAMSUNG SDI 136.
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The main specs from Samsung 30Q datasheet:
Nominal capacity: 3000mAh
Nominal voltage: 3.6V
Standard charge current: 1.5A / 150mA cut-off
Maximum charge current: 4A / 100mA cut-off
Charge end voltage: 4.20V
Max. continuous discharge current: 15A (5C)
Discharge cut-off voltage: 2.5V
AC impedance at 1KHz: ≤26mΩ
Max weight: 48g

Measured initial DC IR at 3A in fully charged condition was 16.0±0.7mΩ (measured using EB Tester Software's tool)

Measured weight of the tested cell was 45.6g
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Samsung 30Q capacity test results:
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At 0.2C (0.6A) 30Q's capacity appeared to be a bit higher than 3100mAh vs 3000mAh declared - a nice start but no surprise. All the way up to 15A it remains above 2900mAh and the curves look excellent. 2.5V discharge cut-off is another advantage which allows to use a wider voltage range. 30Q is a good high drain cell which is a high capacity one at the same time - that's why it's so popular.

Here is the video version of this review:
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Check out my YouTube channel for batteries, chargers and other stuff reviews.
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Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: May 21 2019 7:39am
by john61ct
stellar effort as usual and fine result

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: May 21 2019 10:39am
by izeman
Thanks for the test. I have good results with this cell as well using it in a 15s10p pack at 60A maximum discharge (so no big stress).
Are you planing to do a cycle number test as well? Capacity after 100, 500 or 1000 charges?

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: May 21 2019 8:45pm
by litespeed
I built a 20s15p with these cells and even pulling 200 amps (very seldom but sometimes!😬) with my MaxE the voltage stays so high.......crazy powerful.

Huge change from the 20s15p VTC3 pack I built some time back.

Love them.

Tom

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 02 2019 10:03am
by thunderheart
izeman wrote:
May 21 2019 10:39am
Thanks for the test. I have good results with this cell as well using it in a 15s10p pack at 60A maximum discharge (so no big stress).
Are you planing to do a cycle number test as well? Capacity after 100, 500 or 1000 charges?
Thanks izeman!
No, i'm not doing cycle life tests
litespeed wrote:
May 21 2019 8:45pm
Love them.
Hi Tom!
Lot of people love them)) They're worth it))

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 03 2019 4:23pm
by Drunkskunk
Awesome. I've been looking at these cells for an upcoming project. Looks great!

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 04 2019 1:24pm
by drbenjamin
So does a 2.5V discharge cutoff mean that a 14S pack can be used down to 39.8V and still be at 20%?

(4.2-2.5 = 1.7V/cell total capacity, 0.34V = 20% capacity. 2.5V x 14 = 35V at cutoff, .34x14 = 4.*V for 20% residual capacity)

Asking because 42V seems to be a default LVC for 14S and that would be 30% by my calcs

Thanks!

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 04 2019 2:32pm
by izeman
drbenjamin wrote:
Jun 04 2019 1:24pm
So does a 2.5V discharge cutoff mean that a 14S pack can be used down to 39.8V and still be at 20%?

(4.2-2.5 = 1.7V/cell total capacity, 0.34V = 20% capacity. 2.5V x 14 = 35V at cutoff, .34x14 = 4.*V for 20% residual capacity)

Asking because 42V seems to be a default LVC for 14S and that would be 30% by my calcs
If you look at the discharge curve you'll notive that it is NOT LINEAR, and it differs dependent on discharge current. So you need to take your discharge current, choose the appropriate curve and check where it is for 20% or 600mA left. This is under load though. If you take the lowest discharge curve (purple) it says that at 3.3V (with very little load - so almost resting state) it has 20% capacity left = 46.2V for 14s. At 2.8V=39.8V it's EMPTY.

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 04 2019 4:44pm
by john61ct
In practice even 3.1Vpc is empty, insignificant range left after that

And you're killing longevity even going that low.

Depending on C-rate of course, as a bounceback resting V that's pretty mainstream

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 12:15am
by izeman
john61ct wrote:
Jun 04 2019 4:44pm
In practice even 3.1Vpc is empty, insignificant range left after that
Normally I'd say correct, but this cell has a lower discharge cut off then other cells. Where you normally got till 3.0V max, this cells goes to 2.8V. But of course this is not where the meat is anymore. 8)

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 1:37am
by ridethelightning
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Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 5:29am
by john61ct
izeman wrote:
john61ct wrote:
Jun 04 2019 4:44pm
In practice even 3.1Vpc is empty, insignificant range left after that
Normally I'd say correct, but this cell has a lower discharge cut off then other cells. Where you normally got till 3.0V max, this cells goes to 2.8V. But of course this is not where the meat is anymore. 8)
Going anywhere near that low regularly will murder cycle lifetime.

And again, really not significantly greater range

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 8:46am
by teslanv
I've been specifying the Samsung 30Q cells for my pack builds for the last 2 years. They are good enough that I haven't had the urge to experiment with any other cells.
So yeah, they get my vote. :bigthumb:

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 9:25am
by ridethelightning
I have built 4 large packs with these. they are ok if you have plenty in parallel.
after all the initial discussion about them being good chemistry, like the 20R and 25R cells, I was not very happty to see that they can lose capacity very fast compared to other cells, and my not be that good with regard to cycle life, especially if used as their specs indicate, 15A discharge etc.

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 9:36am
by larsb
Edit: incorrect data removed

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 10:05am
by john61ct
Just from a quick skim, there are so many wildly inaccurate claims on one page I would discount anything written by that author.

And Battery University the site that they're disputing, also has plenty of misinformation, certainly over-generalizations, so would be skeptical of anyone taking it that seriously

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 10:56am
by larsb
Edit: incorrect data removed

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 3:03pm
by drbenjamin
izeman wrote:
Jun 04 2019 2:32pm


If you look at the discharge curve you'll notive that it is NOT LINEAR, and it differs dependent on discharge current. So you need to take your discharge current, choose the appropriate curve and check where it is for 20% or 600mA left. This is under load though. If you take the lowest discharge curve (purple) it says that at 3.3V (with very little load - so almost resting state) it has 20% capacity left = 46.2V for 14s. At 2.8V=39.8V it's EMPTY.
Thanks for the explanation, it makes sense now that you point out that amps (not volts) is the capacity we are interested in.

Thanks again!

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 3:31pm
by john61ct
I have never seen any rechargeable battery chemistry where the curve between average DoD and lifetime cycles did not have a **very** strong causative slope, and all in the same direction.

Claims of such an extraordinary exception would carry the burden of proof, I'm certainly not going to bother building a case for something I consider as obvious as "cells wired in parallel tend toward the same voltage".

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 8:38pm
by MesquiteTim
How would you rate this cell against the 40T?

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 05 2019 10:16pm
by john61ct

drbenjamin wrote:you point out that amps (not volts) is the capacity we are interested in.
Capacity is mAh / Ah / Wh

amps (just like watts) is an instantaneous measure of flow rate, not quantity of energy.

So 20% of the capacity remaining at 3.3V loaded is not "600mA left" but 600mAh.

units are important


Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 11 2019 3:09am
by izeman
john61ct wrote:
Jun 05 2019 10:16pm
So 20% of the capacity remaining at 3.3V loaded is not "600mA left" but 600mAh.
Damnit. Such a mistake happening to me... Me, that constantly corrects other people's posts about SE units, and urges them to use the correct one.
Shame on me! Of course it's mAh.

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 11 2019 9:33am
by john61ct
Oh the shame 8-)

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 13 2019 1:30am
by thunderheart
ridethelightning wrote:
Jun 05 2019 9:25am
I was not very happty to see that they can lose capacity very fast compared to other cells, and my not be that good with regard to cycle life, especially if used as their specs indicate, 15A discharge etc.
At 15A discharge the manufacturer guarantees 60% of the initial capacity at 250th cycle so nobody promised some great cycle life at max discharge rate.
MesquiteTim wrote:
Jun 05 2019 8:38pm
How would you rate this cell against the 40T?
Hmmm... Are you serious?)))) 40T is a 21700 cell, by the way

Re: Samsung 30Q - high drain 18650 Li-ion cell's capacity test

Posted: Jun 13 2019 6:34am
by ridethelightning
thunderheart wrote:
Jun 13 2019 1:30am
At 15A discharge the manufacturer guarantees 60% of the initial capacity at 250th cycle so nobody promised some great cycle life at max discharge rate.
the max claimed peak power for this cell is like 20A or 25A something(sorry cant remember exactly)
so 60% initial capacity at 250 cyles at only 15 A., which i thought they could do comfortably...
not impressed.
so really this is not really a high capacity/high discharge cell at all if you want a decent lifespan.