Samsung 25R/LG 18650HE2/ Sony VTC5 high power 18650 battery

[liveforphysics]

EV packs don't run PTC's, as it's more of a liability than a safety.

Ebikebert- You rock for posting up all the legit datasheets.

All of these new generations of 18650 tool/EV cells are pretty awesome. Did you notice the 106degC in the 25A drain testing? These guys are running some very exotic solvents.

 

[circuit]

how does a bms stop a cell from a short?

BMS does so by preventing battery from overdischarging. When overdischarged, nasty things grow on electrodes and these tend to short out the battery internally during following usage.

say you have a 10p group of cells that one, just one shorts, say when you fall off the bike avoiding a car door, and the + tab is smashed into the - case?

This is why a properly designed battery pack has fuses on each cell. If there are no fuses on each cell, one cell short may and often lead to fire.

most users of Konions are above 30 v so that comment by circuit sounds like nonsense. How does each cell know the total pack volts?

PTC has a maximum allowed voltages, typically ~30V. If you have a 48V battery under load and one PTC goes off, this PTC sees whole battery voltage, which damages it. In result PTC shorts out and it is just like no PTC at all.

In your case a little education would be preferred over calling someone's comments nonsense.

 

[friendly1uk]

I don't have faith in sony's. There have been many product recalls. In 2007 10 million laptop packs (using the 2.15Ah cells) were took out of service. I'm not sure if they went back for reprocessing or were disposed of along the way. In which case the cells will of been for sale again at some point. As the recall was fire related I have to say "No thank you" and accept the internal fuse is not the holy grail.

 

[liveforphysics]

All those early mfg defect Sony cells would be uselessly high Ri when new for Ebikes, and now that it's years forward, they would be lucky to handle 0.5C.

Sony makes premium legit cells, as does Panasonic and Samsung and LG and Farasis and a small handful of others.

 

[friendly1uk]

It is nearly 4 years since the 2010 recall, but as there was a 2009 a 2007 and a 2006 recall too, I just can't trust them. It does not seem a long time ago to me. Just personal opinion of course.

 

[ridethelightning]

Hello Trevor,
OK, we can provide Samsung INR18650-25R cell to you and price is USD4.35 , but QTY:2000pcs. Because this is new model, we just buy this model in the first time.

The difference in quotes we're seeing is interesting. I wonder what's up with that?

after i mailed some of these cheapo shenzen battery conpanies iv had continuous spam ever since.

the only one that only mails me only when i ask some question is supower. the rest say all kinds of stuff,dodgy. the very fact that they push their stuff so hard makes me sus on them.

People call me the most interesting man in the world.

:lol: where do you guys pull this crap out from?

 

[Hillhater]

I don't have faith in sony's. There have been many product recalls. In 2007 10 million laptop packs (using the 2.15Ah cells) were took out of service. ...
...As the recall was fire related I have to say "No thank you" and accept the internal fuse is not the holy grail.

You do know (im sure) that those packs also contain the primary BMS function as well, so who is to say the problem was cell related or some defect in the BMS function.

...This is why a properly designed battery pack has fuses on each cell

Other than Tesla, where else has this been seen ?

 

[circuit]

Other than Tesla, where else has this been seen ?

On every EV race contest. This is mandatory for all participants, written black on white in racing rules.
Also such fusing is available in my 18650 kit.

 

[trevc2]

Other than Tesla, where else has this been seen ?

On every EV race contest. This is mandatory for all participants, written black on white in racing rules.
Also such fusing is available in my 18650 kit.

Care to provide details?

Cheers

 

[circuit]

Other than Tesla, where else has this been seen ?

On every EV race contest. This is mandatory for all participants, written black on white in racing rules.
Also such fusing is available in my 18650 kit.

Care to provide details?

Cheers

I have never studied those documents, because usually they are written in languages that I am not comfortable with (german, french, etc...). But I get a lot of requests from various racing teams for support on BMS topics. Racing participants explain that each parallel cell must have a fuse, also fuses are required for BMS as well, on each sense wire. There are strict rules, commission reviews whole battery implementation and decides whether it meets minimum safety requirements.

Information on my 18650 kit is available here:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=55870

 

[trevc2]

I have never studied those documents, because usually they are written in languages that I am not comfortable with (german, french, etc...). But I get a lot of requests from various racing teams for support on BMS topics. Racing participants explain that each parallel cell must have a fuse, also fuses are required for BMS as well, on each sense wire. There are strict rules, commission reviews whole battery implementation and decides whether it meets minimum safety requirements.

Information on my 18650 kit is available here:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=55870

Oh, that's yours!

I really like that design. I hope you're getting closer to being able to sell them. I'd definitely be interested.

 

[zener]

Make fuses on each cell the IR from the pack higher ?

 

[circuit]

Make fuses on each cell the IR from the pack higher ?

I think that 1-2% increase in Ri is worth of added safety.

Information on my 18650 kit is available here:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=55870

Oh, that's yours!

I really like that design. I hope you're getting closer to being able to sell them. I'd definitely be interested.

It is coming together quite nicely. Technical issues are solved more or less, just some logistics issues are remaining. I also have some LG cells and PCM inbound, will assemble a demo pack soon.

 

[Ebikebert]

Hey guys i have some more information on the Samsung 25R cells. I contacted the trusted reseller supowerbattery111 about the cells and he told me he should have stock of these cells early in march.
The cells he told me should be almost exactly the same price as the Samsung 24R batteries which i was quoted a while back at $6.35 per cell. This per cell price might seem high but it is because he offers a free profesional tab welding service along with the cell spacers pictured earlier in this posting. For shipping he has two options: he can send you the whole pack in one package for around $140 or split it up the package in many boxes and this option is around $60 which is much better. The only negative of recieving many packages is they might come different days but it is worth it in my opinion.

 

[Ebikebert]

EV packs don't run PTC's, as it's more of a liability than a safety.

Ebikebert- You rock for posting up all the legit datasheets.

All of these new generations of 18650 tool/EV cells are pretty awesome. Did you notice the 106degC in the 25A drain testing? These guys are running some very exotic solvents.

Thanks LFP i knew these might have interested people like you.

 

[Hillhater]

Other than Tesla, where else has this been seen ?

On every EV race contest. This is mandatory for all participants, written black on white in racing rules.
Also such fusing is available in my 18650 kit.

I am guessing that EV "Race" battery packs are custom made.
All types of Racing has its own special rule sets, safety clothing, Certified helmets, etc etc to deal with the extremes of racing.
So getting back to the real world that most of us live in.....
....what commercial lipo packs from Panasonic, Sony, Cellman, BMS Battery, etc etc.... have fuses on each cell ?
Im not saying that it is a bad idea, just that it is not standard practice in the " industry" currently.

 

[circuit]

Im not saying that it is a bad idea, just that it is not standard practice in the " industry" currently.

Not standard YET When you look at it more deeply, you could see that even large companies are still very novice in adapting lithium, making many mistakes. Plenty of opportunity for small, flexible companies to take over these niches, while big ones are figuring things out.
I guess Boeing will realize that too, some day. Struggling so long with task so simple, that it is not funny any more.
I don't think that it is wise to look at other manufacturers and say "they do it, so it must be okay". Leaf, for example. No thermal management, no fuses. Just a matter of time, I tell you. On other hand, Leaf is only 2P, so this should be ok, probably. I really hope they did "what if" tests.

 

[Teh Stork]

Other than Tesla, where else has this been seen ?

On every EV race contest. This is mandatory for all participants, written black on white in racing rules.
Also such fusing is available in my 18650 kit.

Well, I'm working as a consultant on a formula student car building the battery pack and I can tell you with 100% confidence that only one pack fuse is needed. So no, cell level fusing is not mandatory in every EV race contest.

Other rules include thermal monitoring of 2 thirds of cells and cell voltage monitoring on every cell.

 

[Ebikebert]

I recieved some good news regarding these cells the trusted reseller supowerbattery111 will have stock of both of these batteries( the 25R and the HE2) in about a month they said. No prices yet

 

[LSBW]

Found this on ET (Russian analog of ES)

http://www.aliexpress.com/item/plas...-52-holes-and-48v-10ah-battery/716013844.html



For 20S10P config it will cost you $80 delivered. Not bad.

 

[Ebikebert]

nice find ! that is a good way to make a huge pack. The ones i pictured are from supowerbattery111 are like lego blocks you just press fit them together to make your pack.

 

[trevc2]

There's Alibaba/AliExpress sellers that have matching Nickel strips too. I assumed you guys already knew about these brackets:

http://www.aliexpress.com/item/18650-battery-holder-cell-bracket-for-DIY-battery-pack-with-matched-nickel-strip/1201936152.html

 

[circuit]

Other than Tesla, where else has this been seen ?

On every EV race contest. This is mandatory for all participants, written black on white in racing rules.
Also such fusing is available in my 18650 kit.

Well, I'm working as a consultant on a formula student car building the battery pack and I can tell you with 100% confidence that only one pack fuse is needed. So no, cell level fusing is not mandatory in every EV race contest.

Other rules include thermal monitoring of 2 thirds of cells and cell voltage monitoring on every cell.

This is strange, because many customers were talking about cell-level fuses. Also I recall this being discussed here on forums.
I will ask to show the document, when I get a chance.

Did a quick google search and found a nice english document. It is about snowmobiles, but probably not that much different. From page 51:

EV6.1.5 If more than one battery cell is used to form a set of single cells in parallel such that groups of parallel cells are then combined in series, then either each cell must be appropriately fused or the cell manufacturer must certify that it is acceptable to use this number of single cells in parallel. Any certification must be included in the ESF.

EDIT: the same text is in "Formula hybrid 2014 rules". Document attached.

 

[madin88]

Well, I'm working as a consultant on a formula student car building the battery pack and I can tell you with 100% confidence that only one pack fuse is needed. So no, cell level fusing is not mandatory in every EV race contest.

Other rules include thermal monitoring of 2 thirds of cells and cell voltage monitoring on every cell.

i also think this is the common way how most of the battery packs are built.
Of course, the cells vary in capacity, resistance etc, but the percentage of a blown cell or short circuit on a battery pack built up from all factory new cells (identical cycles / same abuse) will be probably go to zero. If you do some selection it will be still better..
I think there is more error-proneness due to mechnical defects (vibration, corrosion from a got wet battery etc.). If the pack is built solide, i would say there is no really a need for fuses on every single cell.

 

[friendly1uk]

I don't have faith in sony's. There have been many product recalls. In 2007 10 million laptop packs (using the 2.15Ah cells) were took out of service. ...
...As the recall was fire related I have to say "No thank you" and accept the internal fuse is not the holy grail.

You do know (im sure) that those packs also contain the primary BMS function as well, so who is to say the problem was cell related or some defect in the BMS function.

Sony themselves said it was distance between the layers. Who else are we to believe.

From what little I have read there is no bms, Just a fuse and chemistry that can't over charge. Why are you sure there is electronics in there? (I'm certainly not sure there is)