Search found 317 matches

by docware
Jun 28 2020 5:46am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

This test show comparison between three particular cells, so the only one conlucison is valid for direct comparison of this three cells. No, it is not comparison of three different cells, it is measurement on the same cell (LG HG2 No2). Frankly, I am surprised by such enormous capacity decline, mor...
by docware
Jun 25 2020 3:09pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

Let me remind LG HG2 No2 : LG HG2 No2, production date November 2017. Purchased fom nkon in September 2018. Cell stored at aprox 25 – 40 % SOC, 15° - 20°C. In December 2018 capacity 2 909 mAh at 3 A discharge, measured at ZKETECH EBC-A10H. In September 2019 : 2836 mAh at 1A, 2804 mAh at 3 A, measure...
by docware
Jun 23 2020 1:48am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

If there's one thing I learned in the barrage of data I've seen over the past year or so here, it's what NOT to buy. That alone has saved me a lot of time and money. Well, just be aware that cycle aging is only part of the whole picture. It doesn´t include calendar aging. Interesting fact : capacit...
by docware
Jun 21 2020 10:21am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

I'm sure he's going to continue testing cells in the future anyway. Very probably not, cells testing became boring. Vegetable growing is much more interesting and enjoyable. :) 1.jpg 3.jpg Comparing cells tested at different times, by different people with different equipment is impossible. Wrong, ...
by docware
May 25 2020 3:15pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

Samsung 35E has 87,4 % of initial capacity in the cycling interval 4,1 - 3,4 V / 2,5 A discharge. In standard range 4,2 - 2,5 V at 1 A discharge has 93,6 % of initial capacity and 93,6 % of initial energy. Samsung 35E No2 after 700 cycles 4,2 - 2,5 V 1 A disch comparison.jpg Samsung 35E DCIR after 7...
by docware
May 24 2020 2:13pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

Currently preparing charts for all three cells.
by docware
May 24 2020 9:19am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

Sunday afternoon, no brain capacity for such work :)
But have something better, source Excel file :
DCIR rise Excel file.xlsx
(16.15 KiB) Downloaded 36 times
by docware
May 24 2020 6:20am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

The final batch of data - Samsung 35E, 50E and LG HG2 finished 700 cycles. Samsung 35E 700 cycles.jpg Samsung 50E 700 cycles.jpg LG HG2 700 cycles.jpg Capacity decay comparison zoom offset 24.5.2020.jpg DCIR comparison 24.5.2020.jpg Just as a matter of interest, here is capacity decay comparison wit...
by docware
May 15 2020 8:42am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

If someone start building his own bike with tuneable controller, or when i think about E-mopeds like Surron, the peak C-rate usually is much higher there. Surron as example has 6kW peak power and around 1900Wh battery (Panasonic PF) so already above 3C or 9A per cell. Still not true continuous in m...
by docware
May 15 2020 4:22am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

New data : Samsung 35E 673 cycles, Samsung 50E 650 cycles, LG HG2 658 cycles.
Samsung 35E  673 cycles.jpg
Samsung 35E 673 cycles.jpg (204.12 KiB) Viewed 915 times
Samsung 50E  650 cycles.jpg
Samsung 50E 650 cycles.jpg (223.61 KiB) Viewed 915 times
LG HG2  658 cycles.jpg
LG HG2 658 cycles.jpg (199.78 KiB) Viewed 915 times
Capacity decay comparison  zoom offset 15.5.2020.jpg
Capacity decay comparison zoom offset 15.5.2020.jpg (209.13 KiB) Viewed 915 times
DCIR comparison 15.5.2020.jpg
DCIR comparison 15.5.2020.jpg (164.19 KiB) Viewed 915 times
by docware
May 07 2020 2:51am
Forum: Battery Technology
Topic: High drain vs low drain battery chemistry? What's the difference?
Replies: 22
Views: 772

Re: High drain vs low drain battery chemistry? What's the difference?

Quotations from the article bellow : "Commercial lithium ion cells are now optimised for either high energy density or high power density. There is a trade off in cell design between the power and energy requirements. The cells designed for high power applications used smaller particles of the active...
by docware
May 07 2020 2:18am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

New data : SONY VTC6 700 cycles, Samsung 35E 620 cycles, Samsung 50E 600 cycles, LG HG2 600 cycles. SONY VTC6 700 cycles.jpg Samsung 35E 620 cycles.jpg Samsung 50E 600 cycles.jpg LG HG2 600 cycles.jpg Capacity decay comparison zoom offset 7.5.2020.jpg DCIR comparison 7.5.2020.jpg SONY VTC6 finished ...
by docware
Apr 29 2020 3:58pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

Uf, fortunately I din´t know that my graphs are regularly checked by professional. :) You are right, cells are performing better than in the real life. We should realize that this is only comparative test done at specific conditions, in the real life are conditions different. For example mildly incr...
by docware
Apr 29 2020 4:39am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

I´ll finish the testing within next 2 – 3 weeks. If I start again in September, 40T can be one in the test.
by docware
Apr 28 2020 11:30am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

Maybe it´s time to ask Pajda for his comment on the results.
„I will add general/well known comments to his results. „
viewtopic.php?f=14&t=102387&p=1507776#p1507776

I believe that his remarks are highly wanted not only for me. 8)
by docware
Apr 28 2020 9:09am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

Centurio wrote:
Apr 28 2020 3:43am
Thank you for performing this tests!! There are interesting statistics about these cells. The Sony VTC6 will have reached the 700 cycles soon. The other cells soon after. What cells are you going to test after?
I am about to quit the testing as indicated few weeks ago.
by docware
Apr 27 2020 2:26am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

New data : SONY VTC6 664 cycles, Samsung 35E 557 cycles, Samsung 50E 550 cycles, LG HG2 532 cycles.
SONY VTC6  664 cycles.jpg
SONY VTC6 664 cycles.jpg (201.43 KiB) Viewed 1089 times
Samsung 35E  557 cycles.jpg
Samsung 35E 557 cycles.jpg (201.97 KiB) Viewed 1089 times
Samsung 50E  550 cycles.jpg
Samsung 50E 550 cycles.jpg (222.13 KiB) Viewed 1089 times
LG HG2  532 cycles.jpg
LG HG2 532 cycles.jpg (197.74 KiB) Viewed 1089 times
Capacity decay comparison  zoom offset 27.4.2020.jpg
Capacity decay comparison zoom offset 27.4.2020.jpg (206.15 KiB) Viewed 1089 times
DCIR comparison 27.4.2020.jpg
DCIR comparison 27.4.2020.jpg (162.87 KiB) Viewed 1089 times
by docware
Apr 18 2020 3:58am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

New data : SONY VTC6 600 cycles, Samsung 35E 500 cycles, Samsung 50E 500 cycles, LG HG2 474 cycles. SONY VTC6 600 cycles.jpg Samsung 35E 500 cycles.jpg Samsung 50E 500 cycles.jpg LG HG2 474 cycles.jpg Capacity decay comparison zoom offset 18.4.2020.jpg DCIR comparison 18.4.2020.jpg
by docware
Apr 16 2020 5:31am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

..... but there two scientific reasons why I decided not to do it. The first is my laziness, the second ...... Yes, those scientific principles are important, thanks for inspiration …… :) Well, the absolute storage temperature is not so important, as all samples will have the same conditions and th...
by docware
Apr 14 2020 1:15am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

... i decided to perform a simple calendar (shelf) life test for modern cells. This type of test has great advantage – you don´t need a testing cycler nor fixtures. :) What temperature do you consider for this test ? By the way, for acurate DCIR measurement the cell´s body temperature ( not ambient...
by docware
Apr 12 2020 5:49am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 1772

Re: Help me troubleshoot this pack please. How are these voltages?

Well, this lesson brings advice : don´t waste your time with noname chinese cells and throw them to the hazardous scrap.
by docware
Apr 12 2020 4:03am
Forum: Battery Technology
Topic: Help me troubleshoot this pack please. How are these voltages?
Replies: 59
Views: 1772

Re: Help me troubleshoot this pack please. How are these voltages?

Eikido, it seems to me that your effort to build battery from noname chinese cells is wasting of money and time.
by docware
Apr 12 2020 2:30am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

New SOC comparative chart after 700 cycles. Samsung 30Q and LG MJ1 added.
SOC after 700 cycles comparison.jpg
SOC after 700 cycles comparison.jpg (287.06 KiB) Viewed 1003 times
Samsung 30Q after 700 cycles SOC mapping.jpg
Samsung 30Q after 700 cycles SOC mapping.jpg (190.41 KiB) Viewed 1003 times
LG MJ1 after 700 cycles SOC mapping.jpg
LG MJ1 after 700 cycles SOC mapping.jpg (193.47 KiB) Viewed 1003 times
by docware
Apr 09 2020 4:15am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

New data : SONY VTC6 536 cycles, Samsung 50E 450 cycles, Samsung 35E 450 cycles, LG HG2 412 cycles. SONY VTC6 536 cycles.jpg Samsung 50E 450 cycles.jpg Samsung 35E 450 cycles.jpg LG HG2 412 cycles.jpg Capacity decay comparison zoom offset 9.4.2020.jpg DCIR comparison 9.4.2020.jpg
by docware
Apr 02 2020 2:45pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 472
Views: 48909

Re: Li-ion cells cycle ageing

30Q is the worst from high power cells. During testing after 700 cycles i have learned that 30Q No3 has some inner instabilities. See the first discharge 1 A 4,2 – 2,5 V : Samsung 30Q No3 1A first comparison after 700 cycles.jpg Here see comparison of 30Q No4 (non cycled) with 30Q No3 initial test, ...