Search found 339 matches

by Pajda
May 24 2020 7:48am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

Should I ask for DCIR rise comparison in % without zoom? :)
by Pajda
May 22 2020 1:54pm
Forum: Battery Technology
Topic: NCM cells
Replies: 26
Views: 552

Re: NCM cells

Pajda, do you still stand by this? "HP cells have significantly worse cycle life than most HE cells under low loads up to ca 1-2C continuous discharge. Generally(Although I do not like generalizations) HP cells cycle life is almost independent of the load. That means that HP cells should be used on...
by Pajda
May 22 2020 2:21am
Forum: Battery Technology
Topic: NCM cells
Replies: 26
Views: 552

Re: NCM cells

LFP 90Ah https://www.aliexpress.com/item/4000805306784.html Excellent Varicore / Liitokala don't have the rep of say Winston, CALB, GBS or Sinopoly but that's like half the price, plus free shipping ???? I agree but for that price it is worth of buying sample and run own test. I done this with NMC ...
by Pajda
May 21 2020 3:10pm
Forum: Battery Technology
Topic: NCM cells
Replies: 26
Views: 552

Re: NCM cells

Great stuff Pajda. Have you got any info on reliable makers of quality LFP in that form factor? I realize energy density will be lower. Actually I am not sure if I ever see LFP chemistry in this particular format. But it is because I am not interested in LFP at least till the LFMP cells with at lea...
by Pajda
May 21 2020 2:56pm
Forum: Battery Technology
Topic: NCM cells
Replies: 26
Views: 552

Re: NCM cells

What's the actual sales price of this square puppy? check this store: https://lithiumsystem.ch/produkt-kategorie/lithium-ionen-cells/ncm-en/?lang=en I was ordering from antoher chinese producer for about 60 USD per 50Ah cell in small volume of 10 cells including shipping costs. You can get great di...
by Pajda
May 21 2020 2:12am
Forum: Battery Technology
Topic: NCM cells
Replies: 26
Views: 552

Re: NCM cells

If that is a photo from Ebay/Alibaba/etc....remember you may not get what you see. It's not even a photo--it's just a basic cgi 3d rendering. @Torti; since you don't link to the actual cells, there's no way anyone (even Pajda) can know what those cells are or their specs (at least, what the vendor ...
by Pajda
May 20 2020 3:43pm
Forum: Battery Technology
Topic: NCM cells
Replies: 26
Views: 552

Re: NCM cells

It seems to be VDA-PHEV2 prismatic format with: 27x147x91mm dimensions (91mm is height without the screw terminals). In this particular format you can get 50Ah (some producers claim 53Ah) as "high energy" cell (1C/1C at 100% DoD with >1000cycles life) and 37Ah (some producers claim 42Ah) as "high po...
by Pajda
May 06 2020 3:29am
Forum: Battery Technology
Topic: Help me with materials and crimping for a 21700 battery build
Replies: 20
Views: 582

Re: Help me with materials and crimping for a 21700 battery build

http://budgetlightforum.com/node/67168 That is one test I looked at. Just little warning. This particular test was made on M50 cell sample (grey shrinktube without marking) and bottom vent. I was tested this particular smaples as well and can confirm that they have very good parameters in both capa...
by Pajda
Apr 28 2020 9:57am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

That is actually a very good answer :)
by Pajda
Apr 28 2020 8:16am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

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?
That is actually a very good question :)
by Pajda
Apr 16 2020 8:25am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

However, if you want to be able to see subtle DCIR changes, temperature and soaking time during measurement should be always the same as much as possible. You are absolutelly right, my excuse was that I am aiming on the announced 20% capacity wear, which is usually tied with DCIR rise of about 100%...
by Pajda
Apr 16 2020 8:05am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

I think I remember reading a while back that 35E is very sensitive to charge current , so they may be very decent when charged at low rates around 500-700ma . Just a hunch. That is true, they does not like 0.5C charging rate, the same as GA which is slightly better. On the other side M36 and MJ1 ar...
by Pajda
Apr 15 2020 8:04am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

Thanks for a valuable remarks, yes I can imagine other test setup and maybe in the near future me or someone else will perform them as well. To my test I have to say that I am not fan of using absolute values and I prefer relative comparison. This is also the answer on what temperature did I chose. ...
by Pajda
Apr 13 2020 9:34am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

My oldest cell is a LCO cell from sharp. Had more than 90% capacity after 18 years of storage at room temperature. Now after 22 years it degraded more rapidly Yes this was definitelly a bad one, next time they should offer a better cells or I never again buy anything from Sharp!!! But back to the r...
by Pajda
Mar 08 2020 2:42pm
Forum: Battery Technology
Topic: Batteries involving 40T, 30Q and MJ1 cells. Preferences and opinions.
Replies: 17
Views: 771

Re: Batteries involving 40T, 30Q and MJ1 cells. Preferences and opinions.

zacksc wrote:
Mar 08 2020 1:41pm
The last choice, the MG1, I am thinking is just straight up inferior to the MJ1, but I am not really sure and wondered what other people think about that.
If you are considering "2900mAh" category, avoid the MG1 (very bad cycle life) and think about M29 or 29E7.
by Pajda
Mar 07 2020 3:39am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

zacksc wrote:
Mar 06 2020 3:30pm
Does anyone have an idea where Samsung 40T cells might be in the cycle aging spectrum?
Yes we have
by Pajda
Mar 05 2020 3:44pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

Pajda, could you please comment on my attempt ? Do your 50E tests have similar trend of the capacity ? Continue with the test :) Yes I measured similar trend with my 50E samples. My closest settings is 4.1-3.2V at 0.5C-1C rate. The 50E cycle life is outstanding. Slightly better are only M36 and M29...
by Pajda
Feb 17 2020 3:47pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

New batch of pictures : Samsung 30Q 472 cycles, LG MJ1 435 cycles, SONY VTC6 200 cycles, Samsung 21700 50E 165 cycles, Samsung 35E 125 cycles, LG HG2 64 cycles. 50E curve is obviously influenced by the ZKETECH failure. Yes both cells are definitely artificially damaged by the tester. That is the de...
by Pajda
Feb 17 2020 8:56am
Forum: Battery Technology
Topic: Bosch powertube repair
Replies: 6
Views: 612

Re: Bosch powertube repair

Can you add some photos of disassembled pack? But I agree with others, when the Bosch BMS is disconnected from the battery, it locked itself and it is no longer usable.
by Pajda
Feb 09 2020 5:49am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

Do you still think that calendary aging is not relevant ? Or some worse batch ? The only thing which I am saying again and again is to stop using generalization in the whole area of battery life classification. Each cell, even from another batch/revision of the same production model can have signif...
by Pajda
Feb 08 2020 6:49am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

docware wrote:
Feb 08 2020 4:45am
LG HG2 started yesterday with the same parameters as 30Q and VTC6.
Hmm... LG HG2 should have minimum initial capacity of 2950mAh. My samples was able to deliver this capacity even under 1C disharge rate.
by Pajda
Feb 06 2020 2:10pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

I have a small question, as LG seems to have so much better cycle life, couldn't it be because of the higher LVC? LG was 4,1 - 3,4V, and all other down to 3,3V. Such small difference does not have significant impact on cycle life in SoC window below 70%. If find it quite surprising that if you use ...
by Pajda
Jan 26 2020 3:04pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

Uf.. too much informations. So only one question where to get samples of "141" line of Samsung 30Q in EU for testing?
by Pajda
Jan 20 2020 12:08pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

My understanding is, Samsung 50E is LCO, aka LiCo, lithium cobalt oxide, LiCoO2 Samsung INR21700-50E seems to be NCA-C/Si chemistry cell due to this MSDS https://1dab84c2c05103a7b0db-1e1d21c2e54e342f67cb520004adde98.ssl.cf2.rackcdn.com/MSDS/KLARUS-21GT-50-Ver2-MSDS.pdf I think that there are alread...
by Pajda
Jan 20 2020 11:52am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46897

Re: Li-ion cells cycle ageing

docware wrote:
Jan 18 2020 3:11pm
Something like that ?
Thats it :thumb:

And great choice of new cells.