100% discharge rate capacity

Batteries, Chargers, and Battery Management Systems.
Ianhill   1 MW

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Re: 100% discharge rate capacity

Post by Ianhill » Feb 09 2020 6:54am

I'm lost for words myself it's like there's no real world test just what someone says and then a load of figures that try to justify flat earth, I and many others have clearly stated there's no truth to any of this it's just mumbo jumbo god knows where this has been picked up but it should be put back down there too there's no science here.

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Re: 100% discharge rate capacity

Post by LuboN » Feb 09 2020 10:03am

Hi goatman, today I returned to this thread and I must say it is unbelievable how far can one misunderstandig go... Your problem is simple. You totally misunderstood and misrepresented the data in datasheet. You have no idea what it is about and for what. Those datasheets are useful only if You understand what and why is written there and this is clearly not that case. You will not get further unless You stop being stuck to that nonsense. Just forget about what You saw in that datasheet and start again learning about Li-Ion battery technology in small steps from sources You are capable to understand.
At normal conditions (to avoid debating about extreme situations):
1. Lower discharge current = higher efficiency (more obtainable energy) and lower wear of the cell
This is valid for all cells 30Q included. At 3A it performs better than at 10A. The problem is, that there are cells that perform way better at 3A than 30Q. If You only need 3A, You don´t want to use 30Q because other cells at that current can last several times more (cycles). But they can´t survive enough cycles at 10A. Which cells are better? It only depends on their usage.

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Re: 100% discharge rate capacity

Post by goatman » Feb 10 2020 12:03am

LuboN wrote:
Feb 09 2020 10:03am
Hi goatman, today I returned to this thread and I must say it is unbelievable how far can one misunderstandig go... Your problem is simple. You totally misunderstood and misrepresented the data in datasheet. You have no idea what it is about and for what. Those datasheets are useful only if You understand what and why is written there and this is clearly not that case. You will not get further unless You stop being stuck to that nonsense. Just forget about what You saw in that datasheet and start again learning about Li-Ion battery technology in small steps from sources You are capable to understand.
At normal conditions (to avoid debating about extreme situations):
1. Lower discharge current = higher efficiency (more obtainable energy) and lower wear of the cell
This is valid for all cells 30Q included. At 3A it performs better than at 10A. The problem is, that there are cells that perform way better at 3A than 30Q. If You only need 3A, You don´t want to use 30Q because other cells at that current can last several times more (cycles). But they can´t survive enough cycles at 10A. Which cells are better? It only depends on their usage.
I agree, its pretty obvious that I know nothing about batteries
everyone says im wrong and I most certainly am but

why hasn't anyone that's saying that im wrong posted a link to the results of a 30q tested 250 times at a 1c constant discharge?

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Re: 100% discharge rate capacity

Post by madin88 » Feb 10 2020 5:54am

goatman wrote:
Feb 10 2020 12:03am
everyone says im wrong and I most certainly am but

why hasn't anyone that's saying that im wrong posted a link to the results of a 30q tested 250 times at a 1c constant discharge?
Nobody but you has to proove anything here. It's your statments which stand against whats known so far about cylce life or aging of LiIon cells.

john61ct   1.21 GW

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Re: 100% discharge rate capacity

Post by john61ct » Feb 10 2020 5:56am

I'm a big believer in asking the universe to provide exactly what you're looking for.

Start a new thread and ask what tests exist that come close, after searching google looking at forums and posting the list of links you find yourself.

Also ask for "best guesses" as to results, I bet the gurus' intuitions are pretty close.

If that isn't helpful then you either need to learn how to do it yourself, or maybe offer to pay someone to do it for you.

All the while ideally also following the self-learning program I laid out for you, with that newly encouraging very conducive humble and open-minded attitude.

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Re: 100% discharge rate capacity

Post by john61ct » Feb 10 2020 6:05am


goatman wrote:everyone says im wrong and I most certainly am
I'm not.

I'm saying, I do not know what specific claim you are making that you think will be reflected in the results of that test.

You need to state your hypothesis clearly enough - written clearly and concisely, using standard units and terms - for people to understand it.


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Re: 100% discharge rate capacity

Post by goatman » Feb 12 2020 4:28pm

spent a little time thinking about how to run a 1c test without equipment. i wanted to see if a battery designed to operate at 1c could be able to maintain a 100%t. i noticed theres people from australia and california, warm climates so i looked up monthly average temperatures.

melbourne seems perfect for ebiking, 9 months of 20C average or better

https://en.wikipedia.org/wiki/Melbourne

im vancouver bc we have 3 months 20C plus and average low of about 10C

https://www.currentresults.com/Weather/ ... verage.php

heres docware

docware » Nov 27 2019 12:06am

To mighty82 : I have checked the chart, seems to be OK, hope you can see the chart now. If not send me PM.

As I mentioned few days ago, another two cells are running the cycling test, Samsung 30Q and LG MJ1. Parameters are the same, charge 1 A, 0,1 A cut-off, discharge 2,5 A, 30Q 4,1 – 3,3 V, MJ1 4,1 – 3,4 V.
Here is brief graphic characterization of both cells at the beginning. It´s interesting to see how MJ1 higher internal resistance affect capacity at 3 A discharge. Thanks to warming of the cell is capacity at 3 A virtually little bit higher, drawing near to 2 A line.

i dont have a 30Q but i have a 17s4p of 25r, should be comparable to a 30q ir

its 50f/10C outside

Image

my bike/battery is inside 75f/23C

Image

set the CA to 10 amps

Image

went for a 10km ride

Image

i spent most of the time using about 650 watts steady and overshot the amps a couple times to 980 watts before the ca restricted it back

Image

the battery temperature after the ride

Image

average speeds

Image

at pretty much 1c steady 680 watts, 10C outside temperature, 30km/h the battery couldnt maintain its 100%t. it fell 8f/4C

this is my version of a real world test at 1c for my climate, ive left the bike outside for 54 minutes to simulate visiting someone for an hour then ill get on the bike and do the same trip to see what happens with the battery temperature.

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Re: 100% discharge rate capacity

Post by goatman » Feb 12 2020 5:34pm

battery temp after 1 hour 57f/13C

Image

after same trip

Image

Image

battery temp didnt change 57f/13C

Image

1c discharge at 10Celsius the battery temp fell to 13C and couldnt generate enough heat to reach 100%t but it was able to maintain its starting temperature . 13 Celsius looks to be 90%t

i still dont know 1c in %a. 97? 95? 100?

at 2c discharge this battery runs at 25C to 30C 100%t in these temperatures and when sitting outside, it will start cold and reach 100%t within a couple kms.

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Re: 100% discharge rate capacity

Post by goatman » Feb 13 2020 7:20pm

now that im realising what cold does to a batteries capacity. it reminded me of a comment es member Larsb said. the battery was 25r and ga and operated it for 2 years doing 50km trips at -15 and 0 and got about 350 cycles out of the battery.

I got the data sheet and the ga can delivers it best discharge at 10C and 0 C. there seems to be cold weather batteries

https://www.orbtronic.com/content/Datas ... 500mah.pdf


25C gave the worst result, isn't that the temperature most people test at? room temperature edit what I just said is not true about capacity, the battery is just hot
Last edited by goatman on Feb 14 2020 12:45am, edited 1 time in total.

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Re: 100% discharge rate capacity

Post by goatman » Feb 14 2020 12:41am

I was thinking a 25r, 30q and 40t are basically in the same family of batteries when it comes to %a %t they are 10 amp batteries. so im starting to look for 25r information.
I found a 10 amp discharge chart, it gets pretty warm near the end 50C

https://www.e-cigarette-forum.com/attac ... pg.497865/

in Samsung 30q li ion thread by, I cant remember if it was pajda or docware but okashira was doing a lot of testing of 30q at 7amp discharge/2amp charge and a tesla cell. ill see if I can find the results if they were posted and bring it over.

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Re: 100% discharge rate capacity

Post by goatman » Feb 14 2020 2:17am

I found it after 650 cycles at 7amps it had about 2000mah compared to 15amp discharge cycled 250 times with 1800mah

viewtopic.php?f=14&t=68556&hilit=okashi ... 5#p1159167

interesting comment about the effect of the houses temperature at 63f and 75f

viewtopic.php?f=14&t=68556&hilit=okashi ... 0#p1147649

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Re: 100% discharge rate capacity

Post by goatman » Feb 14 2020 5:09pm

on one of my bikes I have 17s4p of 25r. 10ah. I had to do a 40km trip so I paralleled my backpack battery 17s3p 18650pd with a 15amp fuse between the packs.

when I left batteries were 75f/23C my amps were set at 40amps. throttle all the way, no pedalling, top speed 60km/h, average speed was 32km/h

outside temp was 53f/11C.

after the trip the backpack battery was 83f/28C, the bike battery was 73f/22C and when I disconnected the batteries they were 1.1v apart. the pd was 60.1 and 25r was 59v. I was just pulling high amps going up a hill and I disconnected before letting the packs balance so that's not a bad volt spread and the 15amp fuse between the packs never blew.

larsb was mixing high resistance cells with low resistance cells in low temperatures.

I just find it interesting that you can mix parallel packs and if they are in the same box the higher resistance pack will keep the lower resistance pack warm at a lower c-rate.

when I was originally testing what fuse to use between the 2 packs, I couldn't blow the 10amp fuse at 36 amps/2200watts.

36amps from 7p should be 5amps/cell. the 10amp fuse blew at 2700 watts.

so if I start with 70v and pull 40 amps/2800watts my 25r pack is delivering about 3c and the pd is delivering around 1c

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Re: 100% discharge rate capacity

Post by goatman » Feb 14 2020 7:08pm

I pretty much found the answer to my question about wether I parallel 2 3p packs or discharge them separately. in cold weather at 1c discharge rate the batteries will get too cold so discharge separately at 2c.

I still don't know what 1c at 100%t does and it doesn't really matter to me but if I look at charging and regen I get an idea.

im talking about the 25r,30q,40t family not 29e,50e,ga

everyone says fast charging at about 1c is bad for cycle life and the charge capacity is 98%ah. im back looking at whats with 1c, charging is 100%t 98%ah. charging at 1.5a gives 100%ah 1005t

why not charge at 2c or 3c to see if you can get 100%t 100%ah and better cycle life with fast charging. I went googling

http://budgetlightforum.com/node/52955

kiriba-ru wrote: Please dont forget that most known high-amp cells were made for power tools, that have 30-45 minutes fast chargers (charge current 1.5-2.0C). I have some 13Q cells from 8-10 years old tool batteries, they were discharged with 8-10Amp load and charged with 4Amp (3C) several hundred times (300-500 full cycles) and half of this cells still have about 1000mAh capacity. Charging with high current is similar to discharging with high current, if cell has big internal resistance it will get hot and degrade fast, but if you use brand high-discharge rate cell you can easy charge them with half of declared continious discharge rate and this rate will be still safety IMO.

For some cells high charge rates very quickly degrade capacity (like to 65% in 100 cycles). It is not just the heat produced by the IR; Li ions cannot intercalate into the graphite anode quickly enough during charge and end up plating instead. Cells like the Sanyo GA and Samsung 35E are particularly susceptible to this.

Some explanation and cycle life testing here:
viewtopic.php?f=14&t=68556&sid=2a46a50...

the answer to this question seems to be with okashira

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Re: 100% discharge rate capacity

Post by goatman » Feb 14 2020 7:21pm

regen, I asked Rswannabe about pumping 20amps of regen into 3p of ga with the phaserunner

viewtopic.php?f=6&t=103634&start=50#p1526265

RSwannabe » Jan 29 2020 10:31pm

My understanding is many BMS do not regulate regen current. Thus when “charging” a battery via regen through the primary output wires, it bypasses the BMS charging charging circuit. That is the case on my battery. In researching what was safe amount of regen amperage, I was told because regen is usually short bursts you can use a higher amperage than would be safe for prolonged charging. The short durations don’t allow the battery to get too hot or create dendrite structures. Justin at Grin indicated he has not seen issues with higher regen amperage hurting batteries.

In regards to the heat sink on my phaserunner, I’ve never even felt it get warm. I don’t think I run my setup near hard enough to really stress it. More research also indicates I’m far more likely to overheat the GMAC motor before the phaserunner gets too hot. And I’ve not gotten close to overheating the motor yet either.

right now im putting 30amps of regen into my 4p battery. 7.5amp burst or 3c burst per cell

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Re: 100% discharge rate capacity

Post by Ianhill » Feb 14 2020 8:55pm

Here's a test for you,
Place a flat lion cell with 3.2v in a ambient room of 20c or so and let it settle around that temp then fully charge it and log the ah the cell takes.

Now place it in a freezer and get the cell to low temp as possible, remove and then discharge it at max c rating watch how many cycle you get and log the ah discharged plus try and watch the temp of the pack as you pull high C out of it, the pack will give half of what it normally could but it's working at its max to do so all most like dead shorting the thing it's really putting the hurt on it.

You will find the cold is killing the cells c rating some cell chemistry is better than others but they all use a chemical reaction that slows with temp and by making them discharge hard in the cold they will actually generate their own heat to the point it can be detrimental to their longevity and this heat is a less efficient cell as in reality it gives very poor range.

How do I know this I used to cycle a Lipo pack on a small scooter charge in the warm and allow the pack to settle first but discharge at negative Celsius temps for 40 mins or so in cold weather, and even when there was ice about I'd get home and my packs would feel warmer than if I'd been riding around 15c or warmer and it's because I was over stressing them and they didn't last more than 80 cycles till cells started to fall like dominos.

Want some advice keep the pack warm and wrap it in some thermal blanket etc in cold weather and keep the c rating low enough so the cells ain't making to much heat.

If you want to know does a battery have a efficiency rating with discharge and the answer really is NO

BUT cells do have an efficiency based on environment factors (temp) that adversely EFFECTS C ratings, cold temps lower the c rating and when trying to pull higher than it can handle heat is created within the cell when pushed to levels at 20c degrees would be no issue and the cell would run fine.

Freeze your battery pack and go for a speed run you will soon know what I mean when your ride feels like it's half of what it could be when it's warm.

It's for this reason I over spec the discharge of my batterys massively becuase I can not regulate on such a small ride so I have a 80amp controller fed from 400amp continuous lipo and it means i will not stress the cells even when cold they give a large chunk of their possible capacity and on hot summer days I can just keep on going adds to range massively.

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Re: 100% discharge rate capacity

Post by john61ct » Feb 15 2020 7:26am

And if you do want warmer batteries to get better performance

as above **do not** rely on the harmfully internally generated temp rise

but pre-warm the pack before setting out.

Ideally by having a design that makes it essy to snap in and out so you can bring it inside.

Insulation + an active warming circuit will help in extreme conditions

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Re: 100% discharge rate capacity

Post by eMark » Feb 15 2020 12:23pm

Ianhill wrote:
Feb 14 2020 8:55pm
... I used to cycle a Lipo pack on a small scooter charge in the warm and allow the pack to settle first but discharge at negative Celsius temps for 40 mins or so in cold weather, and even when there was ice about I'd get home and my packs would feel warmer than if I'd been riding around 15c or warmer and it's because I was over stressing them and they didn't last more than 80 cycles till cells started to fall like dominos.
Well, one thing we'd like to know is how many lost cycles would be forfeited by continual use in cold weather when a Lipo packs high drain keeps it above freezing, say 60 F ?? When the pack feels warm to the touch it may be +95 degrees ... depending on how cold your fingers when you touch the Lipo pack.

Same with RC pilots flying their planes in the winter on a frozen lake. Flying aggressively enough to keep battery temp above freezing, but not so warm as to drastically shorten its cycle life. The question arises with say a VTC6 (20A rating) pack is a recommended drain rate (e.g. 8-10A) that will keep the battery above freezing (e.g. 50 F), while not drastically reducing the charge/discharge cycles.

Isn't this basically what goatman is getting at with lower or higher pack temperature and its affect on discharge rate of capacity; while still achieving a reasonable cycle life longevity? For example with a Kenda etrike with a large Plano container mounted between rear wheels it's perfect for placing say a DIY VTC6 pack in the container with or without provision for auxiliary heating. However, a DIY VTC6 pack with aggressive use could keep the pack above freezing (say 50 F) without any provision for auxiliary heating even if the outside temp is well below freezing.

goatman's possible interest in a high drain cell as a means of providing its own warmth is interesting. What would be interestng to know is whether a VTC6 pack with aggressive use in cold weather makes sense ... OR ... are high drain cells like 30Q and VTC6 more useful for vaping and powerful flashlights than for a DIY ebiking build? The bottom line seems to be that you DON'T build either a low drain or high drain pack with the purpose being aggressive use so that the pack provides enough warmth to keep the pack above freezing (say at least 40 F).

goatman's thread is interesting in that it raises the question whether either 30Q cells or VTC6 cells or 50E 21700 cells are practical for building a DIY ebiking pack. Hopefully, this will be discussed at sometime on docware's ageing thread as he's testing those three cells. 50E has 9.8A rating, so possibly it offers the best of both worlds (aggressive use and longevity) for future DIY builds that aren't as restricted to ebike triangle space. Maybe, the 50E is just the ticket for an electrified motor cycle.

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Re: 100% discharge rate capacity

Post by eMark » Feb 15 2020 12:24pm

john61ct wrote:
Feb 15 2020 7:26am
And if you do want warmer batteries to get better performance

as above **do not** rely on the harmfully internally generated temp rise

but pre-warm the pack before setting out.

Ideally by having a design that makes it essy to snap in and out so you can bring it inside.

Insulation + an active warming circuit will help in extreme conditions
AGREE! :thumb:
Ianhill wrote:
Feb 14 2020 8:55pm
... I used to cycle a Lipo pack on a small scooter charge in the warm and allow the pack to settle first but discharge at negative Celsius temps for 40 mins or so in cold weather, and even when there was ice about I'd get home and my packs would feel warmer than if I'd been riding around 15c or warmer and it's because I was over stressing them and they didn't last more than 80 cycles till cells started to fall like dominos.
Well, one thing we'd like to know is how many lost cycles would be forfeited by continual use in cold weather when a Lipo packs high drain keeps it above freezing, say 60 F ?? When the pack feels warm to the touch it may be +95 degrees ... depending on how cold your fingers when you touch the Lipo pack.

Same with RC pilots flying their planes in the winter on a frozen lake. Flying aggressively enough to keep Lipo pack temp above freezing, but hopefully not so warm as to drastically shorten its cycle life. The question arises with say a VTC6 (20A rating) pack if the drain rate (e.g. 10-12A) is enough keep the battery above freezing (e.g. 50 F), while not drastically reducing the charge/discharge cycles.

Isn't this basically one aspect that goatman is getting at with lower or higher pack temperature and its affect on discharge rate of capacity; while still achieving a reasonable cycle life longevity? For example with a Kenda etrike with a large Plano container mounted between rear wheels it's perfect for placing say a DIY VTC6 pack, or any pack, in the container with (or without) provision for auxiliary heating. However, a DIY VTC6 pack with aggressive use could keep the pack above freezing (say 50 F) without any provision for auxiliary heating even if the outside temp is well below freezing. But ideally not a good idea to warm the cells with aggressive drain.

Any possible interest in using a high drain cell as a means of providing its own warmth is interesting, but how practical? What would be of some interest is knowing whether a VTC6 pack with aggressive use in cold weather makes sense ... OR ... are high drain cells like 30Q and VTC6 more useful for vaping and powerful flashlights than for a DIY ebiking build? Has anyone built a pack using VTC6 cells and how many useful charge/discharge cycles? The bottom line seems to be not to build either a low drain or high drain pack with one purpose being aggressive winter use so that the pack provides enough warmth to keep it above freezing (say at least 40 F).

goatman's thread is interesting in that it raises the question whether either 30Q cells or VTC6 cells or 50E 21700 cells are practical for building a DIY ebiking pack. Hopefully, this will be discussed at sometime on docware's ageing thread as he's testing those three cells. 50E has 9.8A rating, so possibly it offers the best of both worlds (aggressive use and longevity) for future DIY builds that aren't as restricted to most ebike's triangle space. Maybe, the 50E is just the ticket for an electrified motor cycle.
[/quote]
Last edited by eMark on Feb 15 2020 12:38pm, edited 2 times in total.

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Re: 100% discharge rate capacity

Post by john61ct » Feb 15 2020 12:36pm

No one can quantify how many cycles are lost by sup-optimal treatment, just too many variables, interlocking multi-dimensional matrix of causative factors.

Any detectable heat rise generated by chemical activity is shortening lifespan.

This is of course unavoidable to some extent, inherent in high-discharge-rate use cases.

Best you can do is carry more Ah to reduce the C-rate, before choosing higher power-density chemistries, which in itself is choosing shorter lifespan.

So, "as little heat rise as possible", just like "as low average DoD% discharge as possible"

both very important to longevity, but opposed to the values desired in a propulsion use case.

The tensions between those opposites only to be resolved by each user in line with their experience and preferences.

Pat numeric answers not available to make these decisions easy, just general guidelines and boundaries.

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Re: 100% discharge rate capacity

Post by eMark » Feb 15 2020 12:41pm

john61ct wrote:
Feb 15 2020 12:36pm
No one can quantify how many cycles are lost by sup-optimal treatment, just too many variables, interlocking multi-dimensional matrix of causative factors.

Any detectable heat rise generated by chemical activity is shortening lifespan.

This is of course unavoidable to some extent, inherent in high-discharge-rate use cases.

Best you can do is carry more Ah to reduce the C-rate, before choosing higher power-density chemistries, which in itself is choosing shorter lifespan.

So, "as little heat rise as possible", just like "as low average DoD% discharge as possible"

both very important to longevity, but opposed to the values desired in a propulsion use case.

The tensions between those opposites only to be resolved by each user in line with their experience and preferences.

Pat numeric answers not available to make these decisions easy, just general guidelines and boundaries.
Isn't that one bottom line conclusion of goatman's quest when he decided to change thread direction to more about the affects of temperature on useful capacity?

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Re: 100% discharge rate capacity

Post by john61ct » Feb 15 2020 12:57pm

I've made it clear I have no clue what he's on about, leave me out of it.

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Re: 100% discharge rate capacity

Post by Ianhill » Feb 15 2020 1:26pm

eMark wrote:
Feb 15 2020 12:23pm
Well, one thing we'd like to know is how many lost cycles would be forfeited by continual use in cold weather when a Lipo packs high drain keeps it above freezing, say 60 F ?? When the pack feels warm to the touch it may be +95 degrees ... depending on how cold your fingers when you touch the Lipo pack.
I've been doing it with the graphene cells 20ah 10c rated 20c max and I've been using them on a vesc at 12s 80amps max on battery side, I've got alot more cycles out of these compared to my multistars but they didn't puff up they just went bad internally i had them in a small aluminium sandwich to help keep them compressed and stop outgasing deforming the cell and they performed well in the summer when built I was getting 60amp out of 16ah multistars with little heat build up but it was optimum conditions take that temp and drop it 30c and then I got 30 or more cycles till game over errors on the charger and out of balance in the volts range after charging capacity was varying massively between cells.

Stripped the pack down and it was not uniformed to how they failed some on the outside some on the inside nothing that I could use my Quincy knowledge and have a urica moment they had shit themselfs randomly more of a design and manufacturing gamble not really a good repeatable design like a cylindrical cells that have had alot more research and development.

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Re: 100% discharge rate capacity

Post by goatman » Feb 15 2020 1:32pm

I agree with what everyone. is saying. cold starting is going to reduce lifecycle. I have a heated winter jacket good for 6 hours with a 2s2p pack. I can make it 2s3p and I can put a heat pad like that in my battery box while im at work to keep the batteries warm for 9 hours.

the thread has changed, if I think I see something but don't know what im seeing or how to communicate it and it wound up where we are.

so a 30q does good at 7amps, was 650 lifecycles and 2000mah

the german pedalers are interesting. 9 out of 10 30q pack failures. I don't speak german but when you go to their forum I see 10s5p and 10s6p. then look at the bicycle. its a low power bicycle. I think they have a 250 watt restriction. does that mean they are running 36v 20 amp controllers with an absolute max discharge of 1c, I think they pedal also. the packs aren't fixable, the cells fail one after another. the question was, did the germans get a bad batch of batteries. my question is whether 1c did it. Germany has a similar cold weather climate as Vancouver bc. I still don't know what 1c at room temperature is.

im just thinking a 30q might have its best lifecycle running at 2c to 3c and stay away from 1c

other cells like the 50e like the lower c rate and the lower the better if you can keep the temperature at 100%

I was looking at the liito kala 26650 50amp 5000mah looks like a great battery at 10 amps or less and a low c charge rate but fast charging kills it.

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Re: 100% discharge rate capacity

Post by goatman » Feb 15 2020 1:42pm

Cephalotus » Nov 19 2019 7:46am




eMark wrote: ↑
Nov 18 2019 4:46pm

Samsung INR18650-30Q 3000mAh - 15A (NCM :thumb:) ... if and when tested by docware the Samsung 30Q should also have a lower DCIR than either PanasonicPF or SanyoGA (NCA). Cycle tests are only half of the story.

In the German Pedelecforum the 30Q now has a very bad reputation for larger packs. It seems that 9 out of 10 packs fail after just some months of use, because single cells of 30Qs do develop heavy self discharging:

https://www.pedelecforum.de/forum/index ... ten.45011/

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Re: 100% discharge rate capacity

Post by Ianhill » Feb 15 2020 2:00pm

Goatman, you don't have to heat the battery all day it's ok to store cold as long as you warm it before use so have a heat pad warm it hour before you go out depending on how much mass the battery has,
Obviously a single cell will warm faster than a load of them.

I tend to use my ride just after I've charged it normally so I'll bring it indoors for hour or two charge it and then ride it of it was a cold work scenario I'd try to mimic that walm the pack to charge it then keep it warm once charged ready to go and possibly wrap it in a heat blanket or emulate a thermos type environment double wall battery box with a good air gap
Last edited by Ianhill on Feb 15 2020 2:04pm, edited 1 time in total.

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