Search found 325 matches

by Pajda
Mar 08 2020 2:42pm
Forum: Battery Technology
Topic: Batteries involving 40T, 30Q and MJ1 cells. Preferences and opinions.
Replies: 17
Views: 535

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: 382
Views: 38152

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: 382
Views: 38152

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: 382
Views: 38152

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: 412

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: 382
Views: 38152

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: 382
Views: 38152

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: 382
Views: 38152

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: 382
Views: 38152

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: 382
Views: 38152

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: 382
Views: 38152

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.
by Pajda
Jan 18 2020 8:06am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 382
Views: 38152

Re: Li-ion cells cycle ageing

Excellent work docware! But as you know me :wink: , I have again one remark to the cell surface temperature profile graph. I think it would be helpful, particularly for newbies interested in this topic to add a legend (some graphical delimiter) where is in the graph located: charge / rest time / dis...
by Pajda
Jan 08 2020 2:34pm
Forum: Battery Technology
Topic: Best 18650 cell for 3p 18A max
Replies: 23
Views: 996

Re: Best 18650 cell for 3p 18A max

izeman wrote:
Jan 08 2020 11:55am
Who/what is Pajda?
:lol: :lol: :lol: :wink:
by Pajda
Jan 06 2020 2:42pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 382
Views: 38152

Re: Li-ion cells cycle ageing

Hi Great charts and testing but something strikes me as odd. When charged to 4.1V the cells should be approx 90% full, meaning e'g 29E should have about 2.6ah capacity available. But the chart starts 2.2ah ??? Could you please explain this in case I have missed some test info! Love this type of num...
by Pajda
Dec 13 2019 6:11am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 382
Views: 38152

Re: Li-ion cells cycle ageing

Once christmas is in the books , I'm going to try to get the equipment to help with this testing. Notably 2C and 3C loads on M36 , 30Q, 29E, M29, VTC6, and Sanyo UR18650NSX up to around 300 cycles. This is highly appreciated. :) I just recommend to use the same equipment described by docware in the...
by Pajda
Dec 03 2019 11:16am
Forum: Battery Technology
Topic: Optimal Charge Voltage - (LiCo)
Replies: 38
Views: 4369

Re: Optimal Charge Voltage - (LiCo)

. Soooo ... everyone ... DrkAngel, Pajda, flippy, Tesla is in agreement that charging to higher voltages produces faster battery deterioration! Of course, but the main problem, which I am talking about is the level of deterioration at "higher" voltages. DrkAngel I have problem with the graphs in th...
by Pajda
Dec 03 2019 7:48am
Forum: Battery Technology
Topic: Optimal Charge Voltage - (LiCo)
Replies: 38
Views: 4369

Re: Optimal Charge Voltage - (LiCo)

charge voltage is not float voltage. Tesla have many user selectable charging options, where one of them allows to the user (he is warned by the car that it affect battery life) to set range mode (100% charge shown on display) and charge the cells in CC to the 4.2V (ca 404V pack voltage for "85,90 ...
by Pajda
Dec 02 2019 12:58pm
Forum: Battery Technology
Topic: Below 0°C and lithium battery charging
Replies: 10
Views: 1274

Re: Below 0°C and lithium battery charging

In fact yes, all batteries designed in accordance with safety standards must have temperature sensor (even so called protected cells does have integrated temperature sensor on a protective PCB). Almost all "consumer" batteries (which can be easily moved to the heated enviroment) works that they simp...
by Pajda
Dec 02 2019 4:45am
Forum: Battery Technology
Topic: Below 0°C and lithium battery charging
Replies: 10
Views: 1274

Re: Below 0°C and lithium battery charging

There is no magical "wall" for lithium batteries at 0°C. All is about safety and manufacturer warranty. In general only qualified person should operate with bare lithium cells. But common people can operate a battery (cell with some kind of protection/BMS). So for example all major cell manufacturer...
by Pajda
Dec 02 2019 4:25am
Forum: Battery Technology
Topic: Boston-Power Swing 5300 Li-ion cell test
Replies: 129
Views: 20127

Re: Boston-Power Swing 5300 Li-ion cell test

Swing 5300 actually have very low DCIR. Measured by the 10s DCIR method its initial DCIR is almost identical to Sony VTC6. So at recommended 2C max discharge rate it still stay cool. The reason why Swing 5300 does not have higher continuous C-rating is in its thin aluminium case, which starts to puf...
by Pajda
Nov 30 2019 5:12am
Forum: Battery Technology
Topic: Optimal Charge Voltage - (LiCo)
Replies: 38
Views: 4369

Re: Optimal Charge Voltage - (LiCo)

Graph without exact definition of testing method and particularly tested cell sample should not be even published, just because you can not add your own measure to compare. I am in this "bussines" for quite a long time and if it teaches me something, that almost all informations about ageing of cell...
by Pajda
Nov 29 2019 3:47pm
Forum: Battery Technology
Topic: Optimal Charge Voltage - (LiCo)
Replies: 38
Views: 4369

Re: Optimal Charge Voltage - (LiCo)

in general its best to look at peeps here that did the actual testing or companies like tesla that are dumping hundreds of millions in battery tech and their whole business is dependant on batteries. their first gen batteries topped out at 4.05V and their "range mode" is 4.12V. (with slight oversho...
by Pajda
Nov 29 2019 3:24pm
Forum: Battery Technology
Topic: Optimal Charge Voltage - (LiCo)
Replies: 38
Views: 4369

Re: Optimal Charge Voltage - (LiCo)

. Was researching a cell type and found a manufacturer who tested 4.20V vs 4.10V cycling. So lets make some unwanted conclusion from uncle Pajda. 1. All of the graphs in the first post of this topic (source is Battery University?) are minimally obsolete and was minimally obsolete even when they wer...
by Pajda
Nov 28 2019 3:41pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 382
Views: 38152

Re: Li-ion cells cycle ageing

It sometimes seems to me that the mess with the cathode chemistries actually have manufacturers itselves. :roll: One example is Samsung 30Q. In the cell presentation they marked it as NCA cathode cell. https://eu.nkon.nl/sk/k/30q.pdf but in MSDS (Material Safety Data Sheet) documet, they say that it...
by Pajda
Nov 25 2019 3:16pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 382
Views: 38152

Re: Li-ion cells cycle ageing

My testing parameters are different than your, but from your remarks and answers I comprehend that up to now are cells doing according your expectation, isn´t it ? What is your criteria for EoL ? Yes, they are. Your combination of narrow SoC window and particularly rather slow charge rate helps a l...