Search found 224 matches

by Pajda
Mar 10 2019 3:02pm
Forum: Battery Technology
Topic: Searching low € / kWh battery chemistry
Replies: 14
Views: 549

Re: Searching low € / kWh battery chemistry

Actually Samsung 50E seems to be very good choice. I did not ran the entire cycle life test, but I already did 500 cycles in some tests. I am surprised with the test results so far, because it shows much better results than 35E in 18650. It seems it has the same performance in comparison with LG M50...
by Pajda
Feb 23 2019 6:41am
Forum: Battery Technology
Topic: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?
Replies: 28
Views: 2049

Re: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?

No problem :) , I now how the results will look like. It will be a good example for community that designing battery pack for more than 1C continuous discharge rate is problematic even with HD/HP cells in 18650 format like 30Q or HG2.
by Pajda
Feb 22 2019 3:03pm
Forum: Battery Technology
Topic: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?
Replies: 28
Views: 2049

Re: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?

Excellent work again. If I may, I would ask for the same comparison test graph at 5A and please add Samsung 29E to the competition. :wink: I am now running non-standard 3C continuous discharge rate "torture" cycle life tests and Samsung 29E together with Panasonic PF shows excellent results in this ...
by Pajda
Feb 16 2019 6:53am
Forum: Battery Technology
Topic: Samsung 33J - a 21700 Li-ion battery designed for Tesla
Replies: 7
Views: 384

Re: Samsung 33J - a 21700 Li-ion battery designed for Tesla

ANR26650M1B and another high quality LFP cells are still much more expensive than NMC cells. Swing 5300 is cell with sufficient parameters for ESS but my guess is that it is not cheaper than Samsung in high volumes and more important Boston Power company already did not exist, and also they probably...
by Pajda
Feb 16 2019 6:10am
Forum: Battery Technology
Topic: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?
Replies: 28
Views: 2049

Re: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?

As always excellent review from docware. I really appreciate your precision when preparing and performing the test procedure. :bigthumb: He also point on important parameter, that LG in their own datasheet specification for M36T did not use capacity but energy for nominal specification and so they d...
by Pajda
Feb 12 2019 3:19pm
Forum: Battery Technology
Topic: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?
Replies: 28
Views: 2049

Re: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?

Already finished with M36 samples from Nkon my standard 0.5C-1C 100% DoD 1000 cycle life test. In this particular test M36 performs exatly the same as MJ1. In another tests with low loads up to 0.5C charge and 1C discharge with lower DoD, the results are also almost identical. But the significant di...
by Pajda
Feb 11 2019 2:21pm
Forum: Battery Technology
Topic: Samsung 35E vs 30Q Cycle Life
Replies: 26
Views: 1912

Re: Samsung 35E vs 30Q Cycle Life

In short yes, MJ1 is the king of the cycle life at low loads up to 1C average discharge. LG MJ1 holds >85% of its initial capacity after 1000 cycles at 100% DoD cycling 0.5C charge - 1C discharge.
by Pajda
Feb 10 2019 4:24pm
Forum: Battery Technology
Topic: Samsung 20S - high drain 18650 Li-ion cell's capacity test
Replies: 15
Views: 609

Re: Samsung 20S - high drain 18650 Li-ion cell's capacity test

High power/drain cells like 30Q, HG2 or VTC6 are usually not the optimal choice for the "standart traction" application. If you look at e-bike batteries from Bosch or others, they are today in 400-500Wh range for 250W rated motors (they can do ca 500W peaks for couple of seconds and so you are at 1C...
by Pajda
Jan 01 2019 3:23pm
Forum: Battery Technology
Topic: Samsung 35E vs 30Q Cycle Life
Replies: 26
Views: 1912

Re: Samsung 35E vs 30Q Cycle Life

By the way, there is realitevely new modification called Samsung 30QM on the market. I hope I will get samples for testing soon if there is any significant change in parameters.
by Pajda
Dec 26 2018 8:15am
Forum: Battery Technology
Topic: Samsung 35E vs 30Q Cycle Life
Replies: 26
Views: 1912

Re: Samsung 35E vs 30Q Cycle Life

The common 29E (NCM Chemistry) is a cheap and good long life cell if you can accept slightly lower capacity at 2.85ah. Just add a few more parallel cells and you are good to go. Tests performed by Pajda and Flippy reveals it being a very sturdy cell (well in par with twice as expensive LG cells). W...
by Pajda
Dec 23 2018 8:40am
Forum: Battery Technology
Topic: Samsung 35E vs 30Q Cycle Life
Replies: 26
Views: 1912

Re: Samsung 35E vs 30Q Cycle Life

Unfortunately, I do not recommend both cells for typical traction application. :( Samsung 30Q is ideal cell for power tools. It was designed to work at 4A fast charge and more than 10A discharge at 100% DoD without significant heating and still gives you at least 400 cycles before dead. Its capacity...
by Pajda
Dec 11 2018 11:27am
Forum: Battery Technology
Topic: Leaked : New 26 and 65Ah LG cell datasheets for EV - LG E63 (Renault Zoe) and C1.5S
Replies: 11
Views: 1482

Re: Leaked : New 26 and 65Ah LG cell datasheets for EV - LG E63 (Renault Zoe) and C1.5S

Mandres wrote:
Dec 11 2018 10:53am
I wonder why Farasis, LG, A123 are so loathe to sell directly to the public?
Are you really expecting an answer? :mrgreen:
by Pajda
Dec 11 2018 4:51am
Forum: Battery Technology
Topic: Leaked : New 26 and 65Ah LG cell datasheets for EV - LG E63 (Renault Zoe) and C1.5S
Replies: 11
Views: 1482

Re: Leaked : New 26 and 65Ah LG cell datasheets for EV - LG E63 (Renault Zoe) and C1.5S

Yes it is stated in the price list, but I am not sure how many cells you need to order as minimal amount.
by Pajda
Dec 08 2018 1:59pm
Forum: Battery Technology
Topic: Tested my Panasonic cells (Opus), unsure of results
Replies: 8
Views: 417

Re: Tested my Panasonic cells (Opus), unsure of results

2800-2850mAh for PF is perfect result when tested with 700mA discharge rate under lower temp than 23°C. If you look in the datasheet, PF has minimum guaanteed capacity for the new cell of 2750mAh measured at 23°C and 580mA discharge rate.
by Pajda
Nov 10 2018 7:31am
Forum: Battery Technology
Topic: If you are building packs today, which cells to choose?
Replies: 82
Views: 10572

Re: If you are building packs today, which cells to choose?

Thanks ichiban :bigthumb: I do not consider myself an all-knowing battery expert. My specialization is battery application "expertise". I have read many books about battery chemistries and have heard to many lectures of battery experts but I never got the answer on a simple question. "Maestro, can y...
by Pajda
Nov 09 2018 3:02pm
Forum: Battery Technology
Topic: If you are building packs today, which cells to choose?
Replies: 82
Views: 10572

Re: If you are building packs today, which cells to choose?

Unfortunately, DCIR and common discharge tests cannot be used to assessment about cycle life. So you can easily find cell with excellent DCIR, but very poor cycle life. This is the case of Samsung 30Q. LG MJ1 is using Ni-rich NMC technology, I think it is first gen of NMC 811 cathode from LG. The se...
by Pajda
Nov 09 2018 5:12am
Forum: Battery Technology
Topic: If you are building packs today, which cells to choose?
Replies: 82
Views: 10572

Re: If you are building packs today, which cells to choose?

Is there any news on your 29E cycle test? Yes, I already finished my standard set of cycle life tests (0.5C-1C and 1C-1C with different DoD) for Samsung 29E. The direct competitors are Panasonic PF and LG MG1 (soon will be replaced by the new LG M29). I do not have yet all tests for MG1 so I can no...
by Pajda
Oct 16 2018 1:44am
Forum: Battery Technology
Topic: Which battery chemistry for extreme climates?
Replies: 37
Views: 1343

Re: Which battery chemistry for extreme climates?

This is a good question, I was trying to find something about this topic too. I also run some tests at -20°C with A123 and Boston Swing 5300mAh cells. Generally you can somehow charge all lithium chemistries at cold temperatures but you have to apply a charging current derating. There is no "wall" a...
by Pajda
Oct 13 2018 2:12am
Forum: Battery Technology
Topic: battery options for motorcycle 40kw 400a 24s?
Replies: 5
Views: 351

Re: battery options for motorcycle 40kw 400a 24s?

You should calculate current draw from the nominal battery voltage not from charging voltage. So for 24s it is: 24*3.6-3.7V= 87V. Then you should know the average or continuous power/curent draw. It is very important parameter for choosing proper cells. If your average will be 5kW (1C) from 5kWh pac...
by Pajda
Oct 02 2018 10:36am
Forum: Battery Technology
Topic: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?
Replies: 28
Views: 2049

Re: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?

I have ran LG M36 test in temperature chamber, but for cycle life tests I am using only basement room with stable long term average temperature 22°C (it very slowly changes from 20 to 24°C during the year seasons - I am logging temperature in this room). I do not measure temperature of cells during ...
by Pajda
Sep 29 2018 4:28am
Forum: Battery Technology
Topic: Samsung INR21700-48G
Replies: 36
Views: 6251

Re: Samsung INR21700-48G

I have some new info about cycle life tests for 48G. Under my first standardized test 0.5C-1C 100% DoD settings the results should be marked as "disaster / non usable" I have run this setting on another cell sample with similar result. But then I lower down the charging current to 0.3C (manufacturer...
by Pajda
Sep 21 2018 12:31pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1585
Views: 170805

Re: Thread for new battery breakthrough PR releases

So what is the energy density of the current Farasis cell ? That spec sheet seems hard to track down. But the earlier 25 Ah Farasis cell was 185Whr/kg, ..410Wh/L ...https://evmc2.files.wordpress.com/2013/12/fei-datasheet-imp06160230p25a-pouch-25ah-v5.pdf So if they managed to keep the weight the sa...
by Pajda
Sep 18 2018 9:32am
Forum: Battery Technology
Topic: LiFePO4 in 18650 format?
Replies: 78
Views: 2823

Re: LiFePO4 in 18650 format?

Not all cells, the GA's i have on the torture tester are already losing capacity after 300 cycles. under what settings? My GA samples works fine under 0.5C-1C at 50% DoD(4.2V-3.55V) with only small (up to 5%) capacity loss after 500 cycles. This behaviour is typical for almost all cells on the mark...
by Pajda
Sep 17 2018 3:58pm
Forum: Battery Technology
Topic: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?
Replies: 28
Views: 2049

Re: LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?

It seems like it isn't possible to squeeze more than 3400-3500mAh into an 18650 size cell. Everything else is marketing or better name it sheer fraud similar to those "4000mAh" 18650 cells from unknown brands you will find on ebay.. I am also afraid that robustness and cycle life of those high mAh ...