New 14s battery pack, US18650VTC6 vs NCR18650GA

Batteries, Chargers, and Battery Management Systems.
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by flippy » Sep 19 2019 7:39am

in batteries that are used in winter you can mount bimetal switches that trigger at 15C or so and enable heater pads. i use custom made ones for my high voltage packs that run directly on the bms output with a enable switch to turn it off or on manually so it can run even when the car/vehicle is off. using low power pads is very important so the battery heats up evenly. that can take hours to get a battery up to temp and then the heater only has to hold it there. then its just like riding in summer and you get way less sag.
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Jan-Erik-86 » Sep 19 2019 7:46am

I guess accepting a shorter battery life and use cheaper cells could possibly be an option, but it will be more of a last option though, as the cell's price difference isn't really that huge. 4-5x Vruzend kits, shipping, and tax make up a lot of the total price.
I am prepared to spend the money for a good pack that will deliver good performance for years to come, both summer and winter. The ~140€ price difference between a 14s8p PF pack vs a VTC6/GA pack is to me less important then the performance and durability of teh pack.

I understand batteries don't like the cold very well, but it's it only charging below freezing that directly damages the li-ion cells? If i understood good, one can still charge at +5c and discharge in freezing, just with a much lower charge/discharge rate? Or does this still degrade them a lot quicker?
I guess i could push the storage temp up to +10c instead of +5c, but would this make much difference?

As far as charge voltage, yes, i intend to charge to no more then 4-4.1V except right before i go on longer trips.

Edit: I guess using heating pads could be an option too. I'll look more into this. :)

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by docware » Sep 19 2019 8:19am

Jan-Erik-86 wrote:
Sep 19 2019 7:46am

I am prepared to spend the money for a good pack that will deliver good performance for years to come, both summer and winter.
Then the heating pads is only solution for you (I didn´t know that solution is used on ebike)

And forget about NCR18650GA.
Last edited by docware on Sep 19 2019 8:41am, edited 1 time in total.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by john61ct » Sep 19 2019 8:33am

Yes must preheat to get decent performance.

Relying on internally generated heat from the increased resistance greatly stresses the pack.

And for charging, lowering the charge rate, to say below 0.1C, only goes so far, very dangerous IMO.
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Jan-Erik-86 » Sep 19 2019 10:38am

Ok, so if we say that i will have the pack pre-heated to 20c or so before riding off, and ignoring the very few times i'll have to park it outside in the cold, does this change anything as far as what cells are recommended?

I see some of you recommend NCR, and some say forget the GA, so i'm a bit confused..

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by leffex » Sep 19 2019 11:40am

Jan-Erik-86 wrote:
Sep 19 2019 10:38am
Ok, so if we say that i will have the pack pre-heated to 20c or so before riding off, and ignoring the very few times i'll have to park it outside in the cold, does this change anything as far as what cells are recommended?

I see some of you recommend NCR, and some say forget the GA, so i'm a bit confused..
I see a lack of efficiency using a module build system for the battery by only clamping them together. Especially when you use a high amp draw from the battery. What battery have you got right now and how is it build?

For cells I just tested: USED 18650 PANASONIC PF. They saged 1,91v for a (5s24p) pack at 150a load. A 12p pack with the same cell would in my estimates sag 3,82v. Calculating linearly gives a voltage sag for a 14s12p battery pack at 75a* load to 5,3 volt.

I like these cells for reasons. Panasonic PF 2900. Panasonic / Ga 3350, Panasonic BD, Samsung 25R. Sony cells I give thumbs up but have not tested, learned so much about or used myself. Other cells I like to try and that I believe in are 20700 Sanyo B, 21700 Samsung 40T and 50E. (4250mah 15a, 4000mah 35a, 5000mah 10a rated)

*(note: half load 75a)
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Jan-Erik-86 » Sep 19 2019 12:12pm

The pack i currently use is a 14s12p pack, but it's split up into a 7p and 5p pack. The 7p pack is using unknown generic chinese cells, and the 5p pack is using a mix og used laptop cells. Total capacity is around 28Ah, but it sags quite a lot and i do feel the lack of power due to the sag. While this pack still works, i want a pack with much less sag, and one i can fit inside the frame.

Currently i need to have the 5p pack mounted on a seatpost rear rack, and I've already "nearly lost" the 5p pack twice in just one season, so the new pack will be firmly mounted inside the frame... :)
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by docware » Sep 19 2019 12:43pm

Triangle inside the frame is ideal for 14s5p or 14s6p Samsung 21700 50E (25 Ah or 30 Ah) battery pack.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Pajda » Sep 19 2019 2:20pm

Jan-Erik-86 wrote:
Sep 19 2019 10:38am
I see some of you recommend NCR, and some say forget the GA, so i'm a bit confused..
This contradiction is based on fact, that many users of GA usually does not have comparison with other cells after even few cycles. GA shows very nice parameters under initial capacity/internal resistance test as a brand new cell, but unfortunatelly it wears very fast when using. Even lower DoD operational window like 4.15V-3V (90% DoD) or 4.1-3.2V (70% DoD) does not help when compared with its main competitors. For example GA still wears faster cycled at 4.1-3.2V (70% DoD) than the LG MJ1 or M36 cycled at 100% DoD.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Pajda » Sep 19 2019 2:44pm

cwah wrote:
Sep 19 2019 2:39am
Pajda wrote:
Sep 19 2019 2:27am

Anyway all of the BD,BE,BM line is outdated and there are much better choices for DIYers.
What are the better ones which would make sense financially?
If you insist on 3200 mAh capacity then it is LG MH1. This cell is used by many ebike producers and it has significantly better operational life than BD,BE and BM. In fact almost all 18650 cells from LG Chem production line excels in cycle life. It is based on my measurements that LG NMC chemistry simply outperforms Panasonic NCA in this particular parameter. Panasonic NCA 18650 production shows muscles as a brand new cells but unfortunately they wear very fast, particularly at higher DoD and charging rate more than 0.3C.

But even LG can make a bad cells, LG MG1 was an epic fail at least the samples I have tested. Fortunately they recently replace it by excellent M29 cell which seems to outperform even Samsung 29E in almost all parameters including price. And also LG 21700 M50T cells have big troubles with cycle life (it is not as bad but it does not reach the quality of M36). On the other side, overall parameters of Samsung 50E is a big surprise for me and it is now the only choice in 21700 HE cells category.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by cwah » Sep 19 2019 2:51pm

Pajda wrote:
Sep 19 2019 2:44pm
cwah wrote:
Sep 19 2019 2:39am
Pajda wrote:
Sep 19 2019 2:27am

Anyway all of the BD,BE,BM line is outdated and there are much better choices for DIYers.
What are the better ones which would make sense financially?
If you insist on 3200 mAh capacity then it is LG MH1. This cell is used by many ebike producers and it has significantly better operational life than BD,BE and BM. In fact almost all 18650 cells from LG Chem production line excels in cycle life. It is based on my measurements that LG NMC chemistry simply outperforms Panasonic NCA in this particular parameter. Panasonic NCA 18650 production shows muscles as a brand new cells but unfortunately they wear very fast, particularly at higher DoD and charging rate more than 0.3C.

But even LG can make a bad cells, LG MG1 was an epic fail at least the samples I have tested. Fortunately they recently replace it by excellent M29 cell which seems to outperform even Samsung 29E in almost all parameters including price. And also LG 21700 M50T cells have big troubles with cycle life (it is not as bad but it does not reach the quality of M36). On the other side, overall parameters of Samsung 50E is a big surprise for me and it is now the only choice in 21700 HE cells category.
Thanks that's good to hear. When looking at the datasheet, it shows 70% lifecycle after 500 cycles:
https://produktinfo.conrad.com/datenbla ... 200MAH.pdf

It's actually less than the NCR18650BD which has close to 80% after 500 cycles?

What makes you say it's much better?
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Pajda » Sep 19 2019 3:28pm

cwah wrote:
Sep 19 2019 2:51pm

Thanks that's good to hear. When looking at the datasheet, it shows 70% lifecycle after 500 cycles:
https://produktinfo.conrad.com/datenbla ... 200MAH.pdf

It's actually less than the NCR18650BD which has close to 80% after 500 cycles?

What makes you say it's much better?
There is only one advice: Do your own measurement for both cells side-by-side. Under my standardized test procedure 0.5C-1C at 100% DoD (actually it is more abuse than LG MH1 cycle life test in datasheet) and there is 92% of initial nominal capacity after 500 cycles and 86% after 1000 cycles for MH1. For BM it is 80% after 500 cycles and 72% after 1000 cycles.

BM as a brand new cell shows higher initial capacity and slightly lower DCIR than MH1 which is of course, as I previuosly mentioned, very confusing for unexperienced user. :?

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by john61ct » Sep 19 2019 8:04pm


cwah wrote:What makes you say it's much better?
Forget maker claims, listen to Pajda, or test yourself

john61ct wrote:You **cannot** base purchase decision on lab tests comparing longevity across different vendors.

Between lines from a single maker, maybe.

Same with generalizations from BU and other sites.

Longevity is not an attribute explicitly aimed for, the market cares about density and C-rates, and both of those may well sacrifice longevity.

Thus older formulations with great **user** reputation for longevity is a decent basis.



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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by cwah » Sep 20 2019 2:07am

Pajda wrote:
Sep 19 2019 3:28pm
cwah wrote:
Sep 19 2019 2:51pm

Thanks that's good to hear. When looking at the datasheet, it shows 70% lifecycle after 500 cycles:
https://produktinfo.conrad.com/datenbla ... 200MAH.pdf

It's actually less than the NCR18650BD which has close to 80% after 500 cycles?

What makes you say it's much better?
There is only one advice: Do your own measurement for both cells side-by-side. Under my standardized test procedure 0.5C-1C at 100% DoD (actually it is more abuse than LG MH1 cycle life test in datasheet) and there is 92% of initial nominal capacity after 500 cycles and 86% after 1000 cycles for MH1. For BM it is 80% after 500 cycles and 72% after 1000 cycles.

BM as a brand new cell shows higher initial capacity and slightly lower DCIR than MH1 which is of course, as I previuosly mentioned, very confusing for unexperienced user. :?
Thanks. So you also mentioned M36?
https://eu.nkon.nl/rechargeable/18650-s ... h-10a.html

This one has good life cycle and calendar life? I may as well buy this one if that's the case
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Jan-Erik-86 » Sep 20 2019 2:30am

So i'm falling more towards the PF or 29e then, understanding this is a better option then the GA in the long run as they are both cheaper and last longer, with the downside being less initial capacity and more voltage sag. When comparing these two cells, which would be the better one? They cost exactly the same, so...

Pajda, just out of curiosity, i know you tested the VTC6 cycle life in the past, did you ever finish the test, and how were the results?
And regarding the MJ1, am i misunderstanding what you said back in 2018, or didn't you say the opposite back then - that the GA was the only one still holding 70% charge even after 1000 cycles when compared to the 35e and MJ1?
Pajda wrote:
Apr 12 2018 4:58pm
It is hard to answer even if i have all three cells measured for their cycle life. When you plan to use only 50% DoD average, all cells do the job well. I will personally prefer LG MJ1 for this. But if you are looking for >80% DoD average and you are thinking about more than 500 cycles, the only way is to go with NCA chemistry cells and so Sanyo GA.

Under my standard 0.5C charge - 1C discharge cycle life test at 100% DoD, the Samsung 35E is "dead" after 300 cycles and LG MJ1 after 500 cycles. "Dead" means reaching 70% initial capacity inside the very steep capacity drop. This behavior is typical for all NMC cells in 18650 format which I have measured. But until then they shows only relatively small capacity drop.

Only Sanyo GA is holding its capacity above 70% even after 1000 cycles under 100% DoD. All NCA cells I have measured shows opposite behaviour than NMC cells. They starts with a relatively steep loss of capacity, but there is visible a slow settlement, where around 1000 cycle the capacity loss is almost stopped.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by flippy » Sep 20 2019 2:48am

in my testing the 29E does better under heavy loads then the PF and is also a bit more durable. but not by much. the main difference is that the 29E is cheaper and has a bit flatter discharge curve under load.
the GA is not even in the same ballpark and should not be used for ebikes. imho.
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Jan-Erik-86 » Sep 20 2019 3:22am

I see, so out of those two, 29e is the best. Thanks! :)

Other alternatives; how would the HG2 (more expensive, but i remember a lot of good talk about it), MH1 (higher capacity, seemingly very good cycle life and low price), or M36 (much higher capacity, low price, but also low current rating) perform up against the 29e in terms of cycle life and power handling (MJ1 of out or stock, so not an option)?
Last edited by Jan-Erik-86 on Sep 20 2019 10:38am, edited 1 time in total.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by flippy » Sep 20 2019 3:45am

anything with higher capacity will die faster.

note: the PF does have much better lifespan when the loads are reasonable. the 29E can just take more abuse in my tests.
if you have a sub 1C discharge and stop at 4.05V then the PF will outlast the 29E by far.
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by cwah » Sep 20 2019 5:57am

flippy wrote:
Sep 20 2019 3:45am
anything with higher capacity will die faster.

note: the PF does have much better lifespan when the loads are reasonable. the 29E can just take more abuse in my tests.
if you have a sub 1C discharge and stop at 4.05V then the PF will outlast the 29E by far.

Why higher capacity dies faster?
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by flippy » Sep 20 2019 6:41am

cwah wrote:
Sep 20 2019 5:57am
Why higher capacity dies faster?
its inherent in the chemistries used. that is why they use high capacity cells in cars and they utterly baby them in the car with cooling, heating and extremely conversative SoC and DoD numbers to get a reasonable lifespan out of them. tesla packs are good for 500k miles or more for example so they pretty much nailed it as most cars wont survive that milage. getting a zoe to do the same would require half a dozen battery swaps due to poor/cheap choices in battery construction.

batteries used in power tools for example are much lower capacity but can deliver and recieve much higher currents without dying too fast. putting a high capacity cell in a power tool would probaly end up with a burning battery. on the other hand would a low capacity cell in a car work great as you can get insane power levels but the range would be 70% less.
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Jan-Erik-86 » Sep 20 2019 10:38am

I see, i guess the M36 is out of the question then? So currently my options are: PF, 29e, M29 or MH1.

So the PF will outlast 29e if used at less then 1C, but i will be pulling ~2c several times daily though, so does that mean the 29e is better for my use?
According to Pajda, M29 is pretty equal to 29e, but also cheaper. Would this be a better option then both 29e and PF then?

And how does the MH1 stand in comparison?

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by flippy » Sep 20 2019 10:48am

the difference between the PF and 29E is very small. for me the dealbreaker is price, the 29E is simply cheaper.
larger cells are simply a no go, unless you double the amount of cells.
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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by john61ct » Sep 20 2019 11:15am

The higher C-rate factor also depends on time held.

2C is so much lower than the usual RC usage, if you're holding that for 5 minutes, and only occasionally, that's not too stressful.

The .2-.6C range is "optimizing for longevity" when weight is not a factor.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by Pajda » Sep 20 2019 2:21pm

Jan-Erik-86 wrote:
Sep 20 2019 2:30am
So i'm falling more towards the PF or 29e then, understanding this is a better option then the GA in the long run as they are both cheaper and last longer, with the downside being less initial capacity and more voltage sag. When comparing these two cells, which would be the better one? They cost exactly the same, so...

Pajda, just out of curiosity, i know you tested the VTC6 cycle life in the past, did you ever finish the test, and how were the results?
And regarding the MJ1, am i misunderstanding what you said back in 2018, or didn't you say the opposite back then - that the GA was the only one still holding 70% charge even after 1000 cycles when compared to the 35e and MJ1?
Pajda wrote:
Apr 12 2018 4:58pm
It is hard to answer even if i have all three cells measured for their cycle life. When you plan to use only 50% DoD average, all cells do the job well. I will personally prefer LG MJ1 for this. But if you are looking for >80% DoD average and you are thinking about more than 500 cycles, the only way is to go with NCA chemistry cells and so Sanyo GA.

Under my standard 0.5C charge - 1C discharge cycle life test at 100% DoD, the Samsung 35E is "dead" after 300 cycles and LG MJ1 after 500 cycles. "Dead" means reaching 70% initial capacity inside the very steep capacity drop. This behavior is typical for all NMC cells in 18650 format which I have measured. But until then they shows only relatively small capacity drop.

Only Sanyo GA is holding its capacity above 70% even after 1000 cycles under 100% DoD. All NCA cells I have measured shows opposite behaviour than NMC cells. They starts with a relatively steep loss of capacity, but there is visible a slow settlement, where around 1000 cycle the capacity loss is almost stopped.
Jan-Erik-86 you disclose my skeleton in the closet :) I later find that this particular sample of MJ1 was somehow handicapped. It sometimes happen that cell is holding its capacity/DCIR for even hundreds of cycles and then suddenly the capacity starts droping in unexpected much faster rate. But still I must make another mistake because this MJ1 sample still holds its capacity to 700 cycle nicely and then starts with fading. I run another four tests under similar conditions and other MJ1 samples does not suffer with this problem and holds 83% of its nominal capacity even after 1000 cycles. So I must appologize for this claim about MJ1. Information about Samsung 35E and Sanyo GA cycle life under 0.5C-1C 100% DOD are correct, both suffer with 0.5C charge rate. Under lower 0.3C charge rate they perform significantly better but still cannot match MJ1 and M36.

Yes I have finished this VTC6 test and already running another tests at lower DoD. This cell does not like high DoD (instead of M29, M36 or MJ1) and so its capacity is fading fast at 0.5-1C 100% DoD, particularly at the begining, so it have ca 77% of its nominal capacity after 500 cycles and 72% after 1000 cycles. The good thing on this cell is that its capacity and DCIR fading is almost independent on chage or discharge rate. Under 0.5-3C 100% DoD it is ca 71% after 1000 cycles. Under 1C-1C 100% DoD it is ca 73% of nominal capacity after 1000 cycles. So it confirms my observation that HP cells like VTC6 should be used only in high continuous discharge apps (like 2C and more), but does not make sense to use it in up to 1C continuous apps, beause they are expensive and many cheaper HE cells have signficantly better cycle life under this conditions.

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Re: New 14s battery pack, US18650VTC6 vs NCR18650GA

Post by cwah » Sep 20 2019 3:03pm

Pajda wrote:
Sep 20 2019 2:21pm
Jan-Erik-86 wrote:
Sep 20 2019 2:30am
So i'm falling more towards the PF or 29e then, understanding this is a better option then the GA in the long run as they are both cheaper and last longer, with the downside being less initial capacity and more voltage sag. When comparing these two cells, which would be the better one? They cost exactly the same, so...

Pajda, just out of curiosity, i know you tested the VTC6 cycle life in the past, did you ever finish the test, and how were the results?
And regarding the MJ1, am i misunderstanding what you said back in 2018, or didn't you say the opposite back then - that the GA was the only one still holding 70% charge even after 1000 cycles when compared to the 35e and MJ1?
Pajda wrote:
Apr 12 2018 4:58pm
It is hard to answer even if i have all three cells measured for their cycle life. When you plan to use only 50% DoD average, all cells do the job well. I will personally prefer LG MJ1 for this. But if you are looking for >80% DoD average and you are thinking about more than 500 cycles, the only way is to go with NCA chemistry cells and so Sanyo GA.

Under my standard 0.5C charge - 1C discharge cycle life test at 100% DoD, the Samsung 35E is "dead" after 300 cycles and LG MJ1 after 500 cycles. "Dead" means reaching 70% initial capacity inside the very steep capacity drop. This behavior is typical for all NMC cells in 18650 format which I have measured. But until then they shows only relatively small capacity drop.

Only Sanyo GA is holding its capacity above 70% even after 1000 cycles under 100% DoD. All NCA cells I have measured shows opposite behaviour than NMC cells. They starts with a relatively steep loss of capacity, but there is visible a slow settlement, where around 1000 cycle the capacity loss is almost stopped.
Jan-Erik-86 you disclose my skeleton in the closet :) I later find that this particular sample of MJ1 was somehow handicapped. It sometimes happen that cell is holding its capacity/DCIR for even hundreds of cycles and then suddenly the capacity starts droping in unexpected much faster rate. But still I must make another mistake because this MJ1 sample still holds its capacity to 700 cycle nicely and then starts with fading. I run another four tests under similar conditions and other MJ1 samples does not suffer with this problem and holds 83% of its nominal capacity even after 1000 cycles. So I must appologize for this claim about MJ1. Information about Samsung 35E and Sanyo GA cycle life under 0.5C-1C 100% DOD are correct, both suffer with 0.5C charge rate. Under lower 0.3C charge rate they perform significantly better but still cannot match MJ1 and M36.

Yes I have finished this VTC6 test and already running another tests at lower DoD. This cell does not like high DoD (instead of M29, M36 or MJ1) and so its capacity is fading fast at 0.5-1C 100% DoD, particularly at the begining, so it have ca 77% of its nominal capacity after 500 cycles and 72% after 1000 cycles. The good thing on this cell is that its capacity and DCIR fading is almost independent on chage or discharge rate. Under 0.5-3C 100% DoD it is ca 71% after 1000 cycles. Under 1C-1C 100% DoD it is ca 73% of nominal capacity after 1000 cycles. So it confirms my observation that HP cells like VTC6 should be used only in high continuous discharge apps (like 2C and more), but does not make sense to use it in up to 1C continuous apps, beause they are expensive and many cheaper HE cells have signficantly better cycle life under this conditions.
Thanks very useful.

Do you have anything about Calendar life or Shelf life? Because to be honest it's very unlikely I'd do 1000 cycles. However, it's much much more likely I'd want to keep the same battery for 5 years or more.

Any comparison in that regards? I thought NCR would do better for calendar life but maybe not?
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