Samsung 29E ver.7 (29E7) 2900mAh cell's capacity test + comparison with 29E ver.6

Original article: https://www.thunderheartreviews.com/2019/08/samsung-29e-version-7-29e7-2900mah-review.html

Less than a month ago i tested Samsung 29E v.6 which many people say is a better cell than the v.7. This time i've tested the v.7 cell and compared them to find out where is the truth. Just to remind, Samsung 29E is a 2900mAh 18650-size cell which supports discharge at up to 5.5A.


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.


I've used version 3.0 of my battery holder based on 0.5mm thick pure copper terminals



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 25±2°C. To be sure in results i've done each test minimum twice (usually 3-7 times).


Samsung INR18650-29E v.7

The cell is marked as INR18650-29E SAMSUNG SDI 7 HJ4T - number 7 stands for the version. This cell has also a 2D barcode on its back which has this code BRHA9E7Q50508297H7TT143509210000000000000 encoded.


The main specs from Samsung 29E datasheet:
Typical capacity: 2850mAh
Minimum capacity: 2750mAh
Nominal voltage: 3.65V
Standard charge current: 1.375A (0.5C)
Maximum charge current: 2.75A (1C)
Charge cut-off current: 55mA (0.02C) (100mA used)
Charge end voltage: 4.20V
Max. continuous discharge current: 5.5A (2C)
Discharge cut-off voltage: 2.5V
AC impedance at 1KHz: ≤35 (45) mΩ
Max weight: 48g

Cycle life:
Using 1.375A (0.5C) charge with 137.5mA (0.05C) cut-off and 2.75A (1C) discharge with 2.5V cut-off after 500 cycles the capacity should be ≥1868mAh (70% of rated capacity).

DC IR at 2.75A in fully charged condition was 26±1.6mΩ (measured using EB Tester Software's Resistance test feature).

Measured dimensions: 18.2mm (diameter) × 64.9mm (length).

Measured weight: 44.55g.


Samsung 29E version 7 capacity test results:

First i need to mention the beauty of curves and that they are as linear as possible! Even the 5A curve! The results are much like those of v.6 but a bit better, so let's compare them step by step.


Comparison

At 0.2C/0.55A discharge:

Only 1mAh difference in capacity and 0.05Wh in energy!!! But the curves are what's important - 29E7 curve looks more linear than that of 29E6 though they are very close.

At 2A discharge:

The difference stars to rise and 29E7 shows 70mAh higher capacity and 325mWh in energy. Again, 29E6 curve doesn't look as linear as 29E7's.

At 5A discharge:

29E7 proves that it's the better cell. 65mAh in capacity and 343mWh in energy is not a huge difference but it exists. Both curves look good and it's not easy to tell which one is better...


Verdict

So, there was no big leap ahead but it's clear that Samsung 29E7 is a better cell than 29E6. Version 6 has slightly lower capacity and energy and nice curves, but version 7 has even nicer ones, almost ideal i'd say. If i had to choose between two versions i'd take v.7 of course.

Here is the video version of this review:


Check out my YouTube channel for batteries, chargers and other stuff reviews.
I've launched my blog where you can find all my reviews in one place. Every new test/review will be first published on YouTube and in the blog. I'll be happy to see new subscribers, comments, suggestions and just your thoughts.

difference is mostly in lifespan.

i did lifecycle testing (another topic) on the E6 and E7 and the E7 had betweem 5% better lifespan under identical loads.

the E6 is a good bit cheaper in volume tho, if you order 500 of them it adds up....

Good to know that. What parameters did you use?

i tested several, full 100% DoD with datasheet numbers as a control, partial DoD with 4.1 and 4.05V and 3V limits and a max charge and discharge according to datasheet.
the 4.05>3V had the best lifespan by far. after 500+ cycles it lost only a few percent.

Thanks flippy for the info, LG M29 seems to be slightly better than E6 in cycle life, so E7 should be equal. I did not test E7. I am curious if E7 can match M29 in 1C continuous charge rate cycle life

flippy said:

the 4.05>3V had the best lifespan by far. after 500+ cycles it lost only a few percent.

Click to expand...

Did you test using just those parameters to see how many cycles it takes to get down to 80% SoH?

I think a standardized protocol would be a tremendous public service.

But personally I would include a benchmark lower C-rate as well as the max one, maybe 0.6C just for comparison, to reveal to what extent longevity performance is related to the ongoing tweaking for power density.

What equipment do you use for your automated cycle testing?

john61ct said:

flippy said:

the 4.05>3V had the best lifespan by far. after 500+ cycles it lost only a few percent.

Click to expand...

Did you test using just those parameters to see how many cycles it takes to get down to 80% SoH?
I think a standardized protocol would be a tremendous public service.
But personally I would include a benchmark lower C-rate as well as the max one, maybe 0.6C just for comparison, to reveal to what extent longevity performance is related to the ongoing tweaking for power density.
What equipment do you use for your automated cycle testing?

Click to expand...

my exact parameters are made to simulate daily use as close as possible for the size of battery i usually make in my products. this is why i also dont use a very temperature controlled enviroment, it gives unrealistic results if the cell does not thermal cycle like it would outside.
i generally dont care about manufacturer given lifecycles as they dont reprisent normal use and lower DoD states have yuge impact on this. just for control i do usually put a single cell into the factory given test and let it run and see if i get the same figures.
my regular tests are with 0.5C or less for lifecycle. for my extended warranty packs i generally aim for a 0.2~0.4C with a 4.05V voltage cap and 3v max discharge. this tend to give the batteries virturally unlimited cycle life, economically speaking.
i use a industrial tester. it is a 8 cells independantly and can do 20A charge and discharge. it costs around 1000USD and i callibrated it with a brymen BM869s.

flippy said:

i tested several, full 100% DoD with datasheet numbers as a control, partial DoD with 4.1 and 4.05V and 3V limits and a max charge and discharge according to datasheet.
the 4.05>3V had the best lifespan by far. after 500+ cycles it lost only a few percent.

Click to expand...

Oh interesting for sure ! How much current can those cells handle in short bursts and still have good cycle life?

flippy said:

my regular tests are with 0.5C or less for lifecycle. for my extended warranty packs i generally aim for a 0.2~0.4C with a 4.05V voltage cap and 3v max discharge

Click to expand...

Excellent!

Is there a centralized blog or something where results are published?

And do you build packs for sale?

Shunt said:

Oh interesting for sure ! How much current can those cells handle in short bursts and still have good cycle life?

Click to expand...

they heat up way too much beyond 8A to put them in a non-cooled pack. but pulling those currents is already killing the battery if you do that for exented periods.

john61ct said:

Is there a centralized blog or something where results are published?
And do you build packs for sale?

Click to expand...

i have posted some data in a different topic i made but a lot of data i keep for myself, most data i make is either made for specific customers that want proof of the expected lifecycles or for me for setting warranty periods.
fun fact: i have not bought several grand of testing equipement just to please a couple guys on a forum.

yes. but i generally dont make the small bike batteries, they are too small to make a profit from to make a living out of.
the small batteries i make are for those mobillity scooters to decrease weight and increase range. old people seem to have difficulty lifing boxes of lead blocks it seems.
i did made a couple for a few (crazy) mountainbikers that wanted to go uphill as fast as they could downhill.

i start usually around the 2kWh (for scooters and small UPS systems) and up to 110kWh for the biggest one i made so far. the latter one for example is desiged for a off grid home solar system and can supply the entire home with 3 phase and charge a electric car at 22kW at the same time. in emergencies it can start a cute little honda 3kW generator when the battery gets below 5% Soc.