Search found 339 matches

by Pajda
Jul 10 2019 7:03am
Forum: Battery Technology
Topic: Looking at building a new pack with Samsung 50E
Replies: 35
Views: 2945

Re: Looking at building a new pack with Samsung 50E

As I previously mentioned it is almost impossible to give relevant information about cycle life of unknown cell without proper measurement. Lishen is big cell producer in China and I think that Tesla asked them about their 21700 cell production for using it in TM3, produced here. But still for me it...
by Pajda
Jul 08 2019 8:09am
Forum: Battery Technology
Topic: Looking at building a new pack with Samsung 50E
Replies: 35
Views: 2945

Re: Looking at building a new pack with Samsung 50E

But for the comparison 50E will do 1000cycles with 85% of its initial capacity and so it totally outperform 40T at 100% DoD in the cycle life if your average load is lower than 1C and you do not need faster charging that 0.5C. @pajda On a typical ride I use say 15A in 60min so I average is 15Ah or ...
by Pajda
Jun 27 2019 7:29am
Forum: Battery Technology
Topic: Correct charge voltage for Samsung 35E
Replies: 7
Views: 685

Re: Correct charge voltage for Samsung 35E

would charging just to 4.1v be better for lifespan than charging set to 4.2v? I charge at 1.02A because datasheet says that's best for lifespan thanks for the amazing quality of responses It differs cell from cell, for example LG cells in 18650 have excellent cycle life even when charged to 4.2V an...
by Pajda
Jun 26 2019 3:50pm
Forum: Battery Technology
Topic: Correct charge voltage for Samsung 35E
Replies: 7
Views: 685

Re: Correct charge voltage for Samsung 35E

"4.1V Li-Ion, 4.2V LiPo and 3.7V LiFePO4" is a historical designation used by almost all modeller chargers. All settings are using the same CC-CV algorithm and it only differs in CV charging voltage. This designation acts only as an aid for novice users that LiFePO4 chemistry has a lower voltage tha...
by Pajda
Jun 26 2019 9:57am
Forum: Battery Technology
Topic: Looking at building a new pack with Samsung 50E
Replies: 35
Views: 2945

Re: Looking at building a new pack with Samsung 50E

After hundred of thousands of cycles on modern small cylindrical cells I can say, that I did not found direct relationship between DCIR value and cycle/calendar life. In fact it is very problematic to find any general rule when considering parameters of new/unknown cell. It is always necessary to te...
by Pajda
Jun 21 2019 1:49pm
Forum: Battery Technology
Topic: Looking at building a new pack with Samsung 50E
Replies: 35
Views: 2945

Re: Looking at building a new pack with Samsung 50E

Short power peaks up to 10 sec actually does not have significant effect on the cell life. Most important is continuous or average charge and discharge current. 65A peak is only 2C rate for 7p pack of 50E and this short peak rate is actually no problem for almost any cell. The question is your avera...
by Pajda
Jun 19 2019 1:32pm
Forum: Battery Technology
Topic: What connector is this please?
Replies: 5
Views: 434

Re: What connector is this please?

Looks similar to Anderson PP15 Series
by Pajda
Jun 13 2019 9:36am
Forum: Battery Technology
Topic: Which cell for long lasting battery
Replies: 32
Views: 3860

Re: Which cell for long lasting battery

Wow good stuff If you insist on longer cycle life (500 full cycles should be enough for most applications) In most of my use cases there is no "enough", daily cycling or dozens per month anyway, usually just replace at EoL defined as 70-75% SoH, so longer the better I give you an example a hard dat...
by Pajda
Jun 13 2019 7:32am
Forum: Battery Technology
Topic: Which cell for long lasting battery
Replies: 32
Views: 3860

Re: Which cell for long lasting battery

Thanks for the info! Can you specify your charge and discharge method, like Voltage, waiting time and so on. What cell would you recommend to me, it doesn't need to be super high energy. I'm only concerned about longevity under relatively mild conditions. I think about the Sanyo GA or Sam. 35E, or ...
by Pajda
Jun 13 2019 6:56am
Forum: Battery Technology
Topic: Which cell for long lasting battery
Replies: 32
Views: 3860

Re: Which cell for long lasting battery

Is HG2 in that 1000cycle club? Sure it is. But HG2 also has its own issues. The problem with HG2 is that it loses capacity very quickly during the first 50 cycles (ca 8-10% of nominal capacity). Between 50-100 cycles the capacity drop start with stabilization and after ca 150 cycle there is only mi...
by Pajda
Jun 11 2019 5:58am
Forum: Battery Technology
Topic: Which cell for long lasting battery
Replies: 32
Views: 3860

Re: Which cell for long lasting battery

Hey guys, at the moment i have a 7P13S battery consisting of 91 LG MG1 and after only about 170 cycles it lost already about 40%. I tested it multiple times and its quite disappointing. My setup looks like following: Charge overnight with about 3A or 0,3C. Commuting to work and back, each way is ab...
by Pajda
May 25 2019 11:47am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 4051

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

nice stats, but they do show the weakness of those bigger cells, they cant handle abuse unlike the 18650... What makes you think that they are weaker than 18650 ? because 18650's generally wear out less fast then that and are cheaper per Wh. Actually from the data I have already collected from 2170...
by Pajda
May 24 2019 12:52pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 4051

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

I think I owe some actual informations about cycle life tests of Samsung 21700 cells. At first I must repeat that I can not show you graphs but I can tell you numbers. :roll: At this time I already reched milestone of 1000 cycles with INR21700-50E under several conditions. I also have 1000 cycles wi...
by Pajda
Apr 19 2019 3:22am
Forum: Items for Sale - New
Topic: QS MOTOR,0.5-14kW Electric Hub Motor Manufacture China
Replies: 1340
Views: 268766

Re: QS MOTOR,0.5-14kW Electric Hub Motor Manufacture China

Sabvoton SVMC72150 + TFT displayer 1) Is this TFT displayer compatible with older Sabvoton controllers? Or it will work (comunicate via UART?) only with the SVMC72150 controller in the set? 2) What is the maximal working voltage for this TFT displayer? It is possible to operate it with 116Vmax batt...
by Pajda
Apr 18 2019 4:15pm
Forum: Battery Technology
Topic: Cells for high drain battery
Replies: 35
Views: 1873

Re: Cells for high drain battery

I'm planning on building a stealth bomber clone e-bike with QS205 4T V3 motor and Mobipus 72200 controller, and i need help finding i'm planing on building a 20s13p configuration with 150A cont. and 300A peak. I have two remarks for this assumption: 1) 150 A cont. at 72 V nominal gives you 10kW sha...
by Pajda
Mar 10 2019 3:02pm
Forum: Battery Technology
Topic: Searching low € / kWh battery chemistry
Replies: 14
Views: 1279

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: 4485

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: 4485

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: 8
Views: 1338

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: 4485

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: 4485

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: 6163

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: 1277

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: 6163

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: 6163

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...