Search found 339 matches

by Pajda
Jan 18 2020 8:06am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

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: 1040

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: 441
Views: 46700

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: 441
Views: 46700

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: 4456

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: 4456

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: 1287

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: 1287

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: 20665

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: 4456

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: 4456

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: 4456

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: 441
Views: 46700

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: 441
Views: 46700

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...
by Pajda
Nov 24 2019 2:03pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

New data, PF, M36 and GA 350 cycles, 29E 300 cycles. We are slowly approaching to 500 cycles, which rises question to Pajda : should we continue beyond this target or start to cycle new cells instead ? Does cycling beyond 500 cycles provide information interesting enough to give reasons for such lo...
by Pajda
Nov 21 2019 4:19pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

Here is another of my unwanted remarks 8) I need to say something about this test https://www.e-cigarette-forum.com/threads/bench-test-results-which-lasts-longer-vtc6-30q-or-hg2.807131/ revealed by Mooch in 6/2017. I'm not afraid to say that if it wasn't published,the world will be a better place. T...
by Pajda
Nov 19 2019 2:55pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

Now that I've seen how awesome the M36 is , it makes me wonder how it would handle 5-7A. The miraculous this cell is not. At 3C continuous it wear out in just 100 cycles. That reminds me. I remember you posting about the M29 a bit . Between all the 2900mah , is the 29e best equipped to handle 2c lo...
by Pajda
Nov 18 2019 5:03pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

Dak77 wrote:
Nov 18 2019 2:45pm
Now that I've seen how awesome the M36 is , it makes me wonder how it would handle 5-7A.
The miraculous this cell is not. At 3C continuous it wear out in just 100 cycles.
by Pajda
Nov 18 2019 4:59pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

My reason for listing the above is wondering if docware intended (has the fortitude) to compare 1000 charge/discharge cycles between PanasonicPF and LG M36 ? Wouldn't a fairer test have been between the PanasonicB and LG M36 being they are similar in capacity (PanasonicB: 3350mAh - 3400mAh and LG M...
by Pajda
Nov 17 2019 2:18pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

Yes, it is important particularly for those who need to operate cells at high continuous C-rates.
by Pajda
Nov 17 2019 12:55pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

If the use case is low mAh, I'm thinking "maybe" the more expensive low resistance cells will last longer, but I have only seen that anecdotally and then again, in high C-rate usage scenarios. I think I got your point. Knowledge of initial cell DCIR value is not really useful for any assumption abo...
by Pajda
Nov 17 2019 10:20am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

I bought a batch of lg mh1. Any chance to chart that out? Thanks LG product MH1 together with MJ1 is surely another interesting cell for testing. :mrgreen: if you once fall into battery testing addiction, you fill find that every cell on the market is interesting until you got at least some initial...
by Pajda
Nov 16 2019 2:01pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

hi doc, thank you for updated graphs. Just few remarks: 1. I will recommend to periodically update graphs only in the first post of this topic and only "bump" that there is an update available. This partial result graphs become obsolete imediatelly after you add updated one. For someone who find thi...
by Pajda
Nov 13 2019 3:46pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 441
Views: 46700

Re: Li-ion cells cycle ageing

doc: do you already have 250cycles data for 29E and GA as well? :wink:
by Pajda
Nov 13 2019 1:22pm
Forum: Battery Technology
Topic: VTC6A 21700 4000mAh Real Price?
Replies: 3
Views: 497

Re: VTC6A 21700 4000mAh Real Price?

I would like to test this Sony VTC6A 21700 and LG H40 cell and comapre them with already tested Samsung 40T. Unfortunatelly I misses when QB have both in stock. I think that 3.6 USD is rather low price for Sony cell, particularly if this is price for one sample. I will expect ca 4 USD and higher pri...