Nasty LiPo fire

[kfong]

Unfortunately I see lipo fires in the ebike world following the same path as lipo fires in the RC world. They have many documented fires. With the ebike segment being much smaller, we are just beginning to see more fires pop up as the ebike community grows. This makes 3 lipo fires within a year with the ES crowd that I know of. If it wasn’t for the size of the packs, the fires would be manageable. Because of the large capacity needed, it’s a risk I don’t find acceptable since I tend to value my life, house, and property a bit more than an ebike. I’ve been avoiding the use of them on ebikes and use them for what they were intended for - RC toys.

I’ve been using lipo’s for a long time when they were available for RC’s and have had a fire, in my case user error. The black soot causes just as much or more damage than the fire itself, it’s caustic and gets everywhere. I would never recommend them to any newbie, when other safer chemistries are available. For those who are using them, it’s best to follow the safety procedures documented by the RC crowd. They have been using Lipo’s far longer and a battery bunker is always good practice when charging or storage.

If I was into racing or performance, Lipo’s would be very difficult to avoid. For the average commuter, it has a higher risk factor than other chemistries. On that note, some of the ebike builds I’ve seen on ES with lipo’s strapped on with duct tape just makes me cringe. These soft baggie cells are too easily damaged. I trail ride and have broken a bike frame completly in half and many bike parts. Lipo’s would not last with the mechanical abuse I put from riding. I would constantly be checking for dents and friction wear.

 

[eva-michael]

See this. Some one in southern France get a unfortune case. But this is LiFePo4 pouch cell so just burn out a bit and demage the cell. Anyway no longer can be used.
Actuall I should say this happens after cells deformation. Many people will neglect the protection when they build there battery pack. I put this online just to let everyone know. That's very imporant even you are using LiFePO4. Isolation and fireproofing structure should always in our mind.



Note: EVA is using headway cell. This one is not from us. It's from one of our customer.

 

[liveforphysics]

The pictures of your LiPo fire inspired me to make a video of some LiPo fun I've had the last month.

[youtube]LExMC5buoFg[/youtube]

 

[amberwolf]

Mmm.... I'd be interested in life-testing anybody's defective or questionable packs that they would otherwise sacrifice to the fire gods.

I'd probably build a metal container for them to be used and charged in, and store them outside away from the house, but I just cringe at all the usable Wh going up in flames.

 

[Hyena]

Wow kepler, just wow.

Like the others I'm now slightly rethinking how I store mine. I have an old retired pack that's puffed slightly under a pile of boxes in my garage. I might go move it now... haha

Were these zippy cells from the international warehouse or the Aussie one ? I noticed just today they're now stocking 25C zippys here, which is awesome (and probably largely because I order so many )
That's an alarmingly high failure rate though that you friend got. Sounds like there may have been a bad batch from HK. I've had the occasional dead cell in a pack but I'd say the last 20 packs I've ordered have all been good.

Curious...

Hopefully this doesn't become a trend!

 

[Fietsbel]

For some extra peace of mind, store the packs in an ammo box, metal, sturdy, water and airtight. Costs almost nothing.




That is what I do with my rc-lipo packs, and always at 40% charge.

This fire is (yet again) a good example of lipo fire danger, one of the many reasons I am switching to lifepo4 cylindrical..

 

[El_Steak]

I like that approach El_Steak. Visual inspection is simple and probably quite effective. What did you use as the clear wrap?

I got the clear wrap from ebay. Good quality and cheap:

http://tinyurl.com/6ew3yy8

 

[Ypedal]

not to get off-topic... but daamn !

http://cgi.ebay.com/ARM-DSO-Nano-Pocket-Sized-Digital-Oscilloscope-2-8-/300404561805?_trksid=p4340.m8&_trkparms=algo%3DMW%26its%3DC%26itu%3DUCC%26otn%3D5%26ps%3D63%26clkid%3D825640388511189627

 

[LiFe]

Sorry. Thankfully there were no injuries or added loss.

Hopefully it'll stand as a serious reminder to others here that you cannot turn your back on LiPo, even when it all seems right.
I also noticed the guy who was big on promoting and establishing their use on ES has also commented in the thread about establishing a safe zone.

 

[Red_Liner740]

What are you guys talking about?!?!

Never turn your back on a lipo?!?

Its been clearly noted by the original poster that these cells were on their very first discharge cycle....so untested cells...

testing hall sensor combos running WOT on the controller. With the motor jerking back and fourth like that = motor stall = max amperage draw.

These were brand new packs that a shallow and light discharge/charge cycle would have weeded out a bad cell...

For the three occurrences of lipo fires, how many people here run lipos without any issues what so ever?? I'm sure the number is in hundreds if not thousands.

"Worlds gonna end" "Think of the children!!"

Its this knee jerk reactions that has led our world to be as frocked up as it is!!

 

[bigmoose]

For some extra peace of mind, store the packs in an ammo box, metal, sturdy, water and airtight. Costs almost nothing.

I use ammo boxes for storage of a lot of things, I like them. Be mindful however if you clamp the lid shut that you may be creating a shrapnel generator if the cells go off in storage. I would consider clamping the lid to get it sealed, then open the clamp. If the internals over pressure, the lid will pop open in the front and no harm done. You may already be doing this, but thought to comment for others.

 

[JohnC]

.

 

[knoxie]

Hey Thats a bummer :?

Can I just say though without wanting to sound too smug I always always always test hall sensor combos with a current limiting power supply for this exact reason, were you running a fuse on the serial harness between the battery and the controller? this depending on the controller could have thumped the pack pretty hard, also have you checked the controller?

Whilst I think it is a good idea to warn of the dangers of lipo we also need to counter the argument by discussing the many many folks like myself who have been using them for 5 years with no problems at all, that said I treat all my batteries no matter what chemistry with great care.

I always fit fuses between cells and on main discharge leads, I always charge the packs on a fire proof blanket with a fire smoke alarm mounted above them and they are always stored in a brick garage, I always check cell balance, I never discharge below 3.3V never charge above 4.1V.

You have to look at the overall risks in fact you must conduct a risk assessment before you use any high capacity battery (would you store a plastic can of petrol in your house?) treat any high energy density material like this and you wont go far wrong.

You can in fact cause more problems by trying to over protect yourself by continually moving the battery and putting in a fire safe or in a concrete bunker, you are as likely to cause an issue doing this with other forms of electrical problems than if you just left the damn thing alone.

Our houses are full of Lipo, think phones, laptops, mp3 players and the like are you going to keep them in a concrete bunker too?

I think what we are looking at here is maybe a combination of a bad cell or a contaminated pack coupled with it being overly discharged during the hall phase combination test on an untested wiring harness and bike / motor combination and to be fair for charging if you read the labels on the cells they warn us all of this.

It wouldnt put me off using them even if I had an incident because I have massively reduced the risks to a point where even if there was a failure it wouldnt burn my house or workplace down, worst case I would loose a bike bag? maybe a bike?

Glad you are all fingers and thumbs though kepler and you have maybe got the smell out of your nose! and to all others reading this, learn from this post but dont be frightened by it, I would never go back to any other chemistry, for me they are worth it

Oh in fact dont buy em!! more left for me and Luke then!!

Knoxie

 

[neptronix]

Oh in fact dont buy em!! more left for me and Luke then!!

Knoxie

Maybe they'll start having 20% off flash sales on the 5000mAh packs again like they did last year if we can scare everyone off.. good thinking

 

[knoxie]

Oh in fact dont buy em!! more left for me and Luke then!!

Knoxie

Maybe they'll start having 20% off flash sales on the 5000mAh packs again like they did last year if we can scare everyone off.. good thinking

Ha ha yes...I always think flash sale on lipos is a funny phrase to use considering the potential risks! the funny thing is you are more likely to die riding your ebike at 30mph than in a Lipo fire but it doesnt seem to stop folks doing it :lol: ....right thats it I am only using A123 cells, they are safe... Ask bill Dube how safe A123 cells are :lol:

[youtube]1pM1j2d1RMU[/youtube]

 

[texaspyro]

not to get off-topic... but daamn !

http://cgi.ebay.com/ARM-DSO-Nano-Pocket-Sized-Digital-Oscilloscope-2-8-/300404561805?_trksid=p4340.m8&_trkparms=algo%3DMW%26its%3DC%26itu%3DUCC%26otn%3D5%26ps%3D63%26clkid%3D825640388511189627

Save your shekels and by the new 4-channel one... more smoother, more faster, more better... almost a usable scope.

 

[neptronix]

See, A123 = totally unsafe also.

*waits for flash sale on A123 cells on HK*

 

[Kepler]

Hey Thats a bummer :?

Can I just say though without wanting to sound too smug I always always always test hall sensor combos with a current limiting power supply for this exact reason, were you running a fuse on the serial harness between the battery and the controller? this depending on the controller could have thumped the pack pretty hard, also have you checked the controller?

Definitely a better way to test and something I will consider in the future. No fuse was used in the serial harness. I doubt if will make a difference with a single cell failure though. Agree that its best practice though.

Whilst I think it is a good idea to warn of the dangers of lipo we also need to counter the argument by discussing the many many folks like myself who have been using them for 5 years with no problems at all, that said I treat all my batteries no matter what chemistry with great care.

I always fit fuses between cells and on main discharge leads, I always charge the packs on a fire proof blanket with a fire smoke alarm mounted above them and they are always stored in a brick garage, I always check cell balance, I never discharge below 3.3V never charge above 4.1V.

You have to look at the overall risks in fact you must conduct a risk assessment before you use any high capacity battery (would you store a plastic can of petrol in your house?) treat any high energy density material like this and you wont go far wrong.

You can in fact cause more problems by trying to over protect yourself by continually moving the battery and putting in a fire safe or in a concrete bunker, you are as likely to cause an issue doing this with other forms of electrical problems than if you just left the damn thing alone.

Our houses are full of Lipo, think phones, laptops, mp3 players and the like are you going to keep them in a concrete bunker too?

I think what we are looking at here is maybe a combination of a bad cell or a contaminated pack coupled with it being overly discharged during the hall phase combination test on an untested wiring harness and bike / motor combination and to be fair for charging if you read the labels on the cells they warn us all of this.

It wouldnt put me off using them even if I had an incident because I have massively reduced the risks to a point where even if there was a failure it wouldnt burn my house or workplace down, worst case I would loose a bike bag? maybe a bike?

Glad you are all fingers and thumbs though kepler and you have maybe got the smell out of your nose! and to all others reading this, learn from this post but dont be frightened by it, I would never go back to any other chemistry, for me they are worth it

Oh in fact dont buy em!! more left for me and Luke then!!

Knoxie

I certainly aren't put off using LiPo's. LiPo's have been very good to me in general. I personally follow most of the procedures you follow when handling these cells. What I was falling down on a bit was my method of storage which I have now rectified. This thread may discourage some people from using LiPo's, but I hope a bit of good rational discussion will serve to make sure those who choose to use these cells have an improved awareness of how these packs need to be handled.

 

[oatnet]

the funny thing is you are more likely to die riding your ebike at 30mph than in a Lipo fire but it doesnt seem to stop folks doing it

:? Sorry Knoxie, you are the man who introduyced me to eBikes in '07, but I can't agree, you are comparing apples and oranges. I get pleasure from riding an ebike, I'm willing to take those risks. The act of storing or discharging LiPo (or any chemistry) is not intrinsically pleasurable to me, so why would I take on those additional risks?

Further, I can choose when to ride an ebike, I can take steps to mitigate the risks, and if I ride into a tree it and die despite those mitigations it won't kill my whole family. I can't choose when a LiPo defect will present itself, and if torches my garage and house, it could kill my whole family.

Anyone who has been in this hobby for a few weeks knows that anything that can go wrong, will. Despite a boatload of experts here saying the new lipo chemistry is safe, we have now seen Lipo ignite. Now if you are one of the folks who go through the hassle of offloading the packs from your bike, charging/storing them in a BBQ, and treating them with respect, you have thought it through. I've also seen a lot of folks who say LiPo isn't a hassle because they charge right on their bike, but I wonder who else they are putting at risk... Since a123 prisimatics weight about the same, and cost about the same (accounting for cycle life), why deal with the hassle or the risk?

-JD

 

[knoxie]

Hi Kepler

There is a distinct lack of electrical safety in many of the builds on here, no short circuit protection for the wiring, duct taped packs to bike frames all manner of Frankenstein wiring jobs but funnily enough as yet none of these builds seem to be the ones with the fires :lol: just luck maybe

I agree folks do need to know the dangers that they may present but this should be obvious and if it isnt then well there is a chance of someone having a big problem on their hands, for me as I have explained I cover the risks to the point where I am happy and dont worry at all about it but I am vigilant and do not let any of this vigilance slide in to complacency based upon my lack of any real problems up to this point.

My new booster pack I made up last night flew by plane, EMS took just 7 days to the UK from HK to me at my desk! great great service, pack is in fine shape no bad cells, they are 20C Turnigy 6S packs, my old packs were Turnigy 25C 6S and are as good as new 1 full year on (remember my shallow discharge and charge cycles) now i am pretty sure the airlines would stop shipping any Lipo battery tomorrow if there were significant risks in transporting them, I know they are already strict on it and many of the couriers consider them Hazmat however there are tens of thousands of these cells up in the air on planes right now in various shapes and sizes.

Thanks for sharing the pictures and do let us know if you get to the bottom of it, the fact still remains that this may have been a harness issue, this can not be ruled out because of your lack of fuses, I always size my fuses to the controller max amps and ensure that the cables are short circuit protected by the fuse, in my day job this is something I do on massive crane systems, you dont want to be relying on the PC board traces in your packs to save you from a short.

Keep us posted

Knoxie

 

[oatnet]

Our houses are full of Lipo, think phones, laptops, mp3 players and the like are you going to keep them in a concrete bunker too?

Huge difference between the 4v 1.6ah cell in my phone, and a 72v 20ah pack. The pack has much more fuel. 72v discharge can generate a pretty hefty plasma ball, 4v, not so much.

My phone is next to me on the bedstand, I'm a light sleeper so I'd know pretty fast. I wouldn't know about the ebike until the garage is engulfed and flames are creeping up the stairs.

-JD

 

[neptronix]

Oatnet, i read your post, and was like pshaw dude! we all know lipo is lighter and more compact!
Then i did the research:

A123 20AH:

480g x 12 = 5760

Turnigy 20C 5ah 5S lipo:

666g x 10 = 6660

you're more right than you thought you were.

I still like lipo for it's modularity and ease of replacing bad bits and pieces. But when you take the weight and size waste of the A123 cylindrical cells out of the equation, indeed.. lipo looks like a silly choice.

 

[knoxie]

the funny thing is you are more likely to die riding your ebike at 30mph than in a Lipo fire but it doesnt seem to stop folks doing it

:? Sorry Knoxie, you are the man who introduyced me to eBikes in '07, but I can't agree, you are comparing apples and oranges. I get pleasure from riding an ebike, I'm willing to take those risks. The act of storing or discharging LiPo (or any chemistry) is not intrinsically pleasurable to me, so why would I take on those additional risks?

Further, I can choose when to ride an ebike, I can take steps to mitigate the risks, and if I ride into a tree it and die despite those mitigations it won't kill my whole family. I can't choose when a LiPo defect will present itself, and if torches my garage and house, it could kill my whole family.

Anyone who has been in this hobby for a few weeks knows that anything that can go wrong, will. Despite a boatload of experts here saying the new lipo chemistry is safe, we have now seen Lipo ignite. Now if you are one of the folks who go through the hassle of offloading the packs from your bike, charging/storing them in a BBQ, and treating them with respect, you have thought it through. I've also seen a lot of folks who say LiPo isn't a hassle because they charge right on their bike, but I wonder who else they are putting at risk... Since a123 prisimatics weight about the same, and cost about the same (accounting for cycle life), why deal with the hassle or the risk?

-JD

No apples and oranges here oat , the point I am trying to make is one of risks and I made it clear in my post that I mitigate the charging storage risks to the point where it is fundamentally more risky and represents far greater peril to me and my family by me riding the bike at 30mph than it is of my choice of battery chemistry, if you follow sensible and simple procedures you wont burn anything down at all.

All chemistries need respect, A123 cells can vent in the same way and the fact that you have loads of interconnects in between each cell brings risks, I would also counter that argument by their relative scarcity (here in the UK) and volume for their weight, I get very high cycle life coz of my shallow discharge and charge level cycles, I like the A123 cells but I couldnt have got 50V 5AH worth of A123 cells for 70 UK pounds in 7 days? so for me there is a very real reason not to use them, remember I dont consider Lipo to be a danger to me because of how I treat them if i did the laptop i have on my lap here would well it wouldnt be on my lap would it :lol:

My friend Dermot here in the UK has his concerns over Lipo and is using A123 cells, that is fine as he has assessed the risks and due to the nature of his work can not risk parking his bike inside various places because of this, however to do this he has had to source the cells from many different places and people, spend a very great deal of time soldering them all up and testing each cell, this isnt for everyone though, Lipo is a high power, affordable easy option, follow the rules and nobody gets hurt 8)

 

[knoxie]

Oatnet, i read your post, and was like pshaw dude! we all know lipo is lighter and more compact!
Then i did the research:

A123 20AH:

480g x 12 = 5760

Turnigy 20C 5ah 5S lipo:

666g x 10 = 6660

you're more right than you thought you were.

I still like lipo for it's modularity and ease of replacing bad bits and pieces. But when you take the weight and size waste of the A123 cylindrical cells out of the equation, indeed.. lipo looks like a silly choice.

Wait wait! you need to factor in the interconnects with the A123 cells whether it be wires studs or copper bars!! they all weigh sumit! whichever way you look at the facts are plain just google it, its 220 whl for Life and 300 whl for Lipo and dont forget the energy density of Lipo is going up all the time at a greater rate.

 

[neptronix]

Wait wait! you need to factor in the interconnects with the A123 cells whether it be wires studs or copper bars!! they all weigh sumit!

Sure. 2 pounds at most? You don't have to use copper bars or studs for under 100amps ( 99% of all ebike builds ), so the interconnection weight could be well under 2lbs..

If you look at lipos, all ya got for interconnections is solder and a little circuit board.

A123 prismatics are not so bad really.