Lipo Fire on Chick Bike

[Green Machine]

You guys are going to get me into trouble getting me to post pics and babbling etc.

That is my hot wifes beloved daisy bike this girl just fired up. I am kind of in a jam here.

Sick brag post again..my wife is smoking hot.

I am into women way out of my league...i would recommend that to all you guys.

But wife and i are recently separated so i am not doing anything that immoral strolling through park with another woman on wife bike. Just killing time really and starting fires.

[AussieJester]

Sorry to hear about the separation buddy, your obviously doing it tough to... in all seriousness though GM, not many know about the interwebs, I wouldn't worry too much about what pics you post..
KiM

[vanilla ice]

Charge bag around the pack + a steel wire basket would have been much more boring.. What all is in that smoke btw? I've inhaled a little before also.

[Green Machine]

You know it was really cool witnessing my first lipo fire.

Now i know why physics is so into it.

The wicker basket didnt make any difference at all. The basket was burned away within a minute or so.

The fire burned for about 8-10 minutes steady not letting off, and not exploding either. It was just a nice solid fire. Like a controlled burn that lasted forever.

I should have started putting sand on it immediatley but i have let so many of these moments pass that this time i did the right thing and instead brought out the camera.

After a few minutes of filming the fire was in full effect. My first thought was we would just sit there and let it burn itself out since the fire was safely elevated on the bike away from starting a golden gate park forest fire.

But then i noticed that because the wicker basket had a metal floor the bike itself was not damaged at all, and with the wicker basket burned away it was easy to just knock the battery away from the bike onto the ground to salvage the bike frame. The only damage to the bike is a little burn marks on the front fender. Imagine the front tire didnt even pop (we rode away).

So only after that realization of bike preservation did i knock the battery to the ground.

And Only then did the frisbee golfers get proactive on putting out the fire afraid somehow that the nearby trees were going to ignite. It turns out a frisbee makes a pretty good shovel. For 8-10 minutes maybe 12 people were just standing around the bike like saying stuff like wow...unbelievable....how traumatic....is it going to explode? how the hell did that happen? An ebike eh? I forgot to mention frisbee golfers are mostly stoners and they were pretty cool about things.

It was a really nice intense but controlled fire.

Shit happens...

[grindz145]

Badass...

Did you shoot them with a gun or something?

[dogman]

Not suprised that mechanical damage to the cells is one possibility of the cause. I keep preaching, put something protective around those batteries. The first lipo fire I ever heard of was caused by a metal battery box having a sharp edge. It cut the cell on an early lifepo4 pack and set a converted vespa on fire. The pack itself was not well secured, and had nothing to protect it but duct tape.


But it could easily have been the battery murdering system let the cells get undercharged. Same thing seems to have been the reason my original ping died. Instead of cutting off, it let the battery discharge to below 1v per cell. (3v) If the bms let it get too low, then it could flame in use later.

Freaking cool though, that you got it on video.

[999zip999]

I'm with Aussie-Jester let's see some pic's of the chick.

[EBJ]

I agree it should have at least been covered in a charge-bag.
It sure would have smoked, but ppl are quite used to seeing smoke come out of cars (actually just steam from radiators, but a lot dont know the difference)
So from a "public safety" standpoint I imagine seeing smoke wouldn't be as bad as seeing flames.

[liveforphysics]

Not all LiPo is sensitive to physical abuse. BMSBattery just happens to make some of the most dangerous LiPo cells I've ever tested. They are as dangerous as original Generation 1 RC LiPo from early 2000.


Here is a modern 20Ah LiPo cell charged to 4.15v, but that got the outer bulk of the tab ripped off from some rough handling, so we decided to do strike it until it would ignite. We were all disappointed. Even an A123 cell smokes and sometimes flames up if you pound it like this. NMC LiPo just lays there and does nothing no matter what you to do it. It also handles >10v overcharge and just sits there taking it.

But sadly, you guy's cant get your hands on these unless you're buying in the 10's of millions of dollars per order, and have an approved pack design by the company that passes all the exhausting safety requirements.

[Arlo1]

But sadly, you guy's cant get your hands on these unless you're buying in the 10's of millions of dollars per order, and have an approved pack design by the company that passes all the

why the hell is that? Or is this just a temp thing?

[scotticeberg]

I want some of those dow/kokam lithium nmc cells. Now, not later.


http://www.dowkokam.com/presskit/english/Dow_Kokam_Customer_Reference.pdf

[fechter]

Daaamn, I'm glad that didn't happen when I was riding your KMX. The batteries are right under your butt on that thing.

The packaging on those Lipo batteries does not look very robust and not really suitable for 'normal' use without some kind of protective housing. I agree that a metal box, even a fairly thin one, would be a great safety enhancement for those.

After the initial "vent with flame" hydrogen gas ignition, they appear to burn much like a container of gasoline. I think if it was inside a can, the amount of flame would be greatly reduced if not eliminated. Somebody posted a video of a Lipo going off inside a steel 'cash box', much like a small tool box. That really seemed to reduce the damage potential outside the box. Any box or container would need a vent of some kind, but I don't think it needs to be terribly large. A flame arrestor screen over the vent might work to prevent any flaming.

In addition to a metal or non-combustible box, some kind of padding to prevent the wires or cells from shorting after an impact would seem like a good idea. I'm trying to think of materials that are durable, non-combustible, withstand high temperatures and also non-conductive. Metal is great except cell connections can short out against it.

[liveforphysics]

After the initial "vent with flame" hydrogen gas ignition, they appear to burn much like a container of gasoline.

The part that burns so well afterwards is the plastic polymer separator.

[mvly]

humm... putting Lipo on the front basket without shox is probably not a good idea. Lipo are unstable when exposed to heavy shock and probably all the pot holes and bumps were compromising the Lipo battery pack. That's just my Opinion. But then again it might be the BMS or both or neither. Too bad the Lipo probably destroyed all the evidence. : )

[liveforphysics]

Lipo are unstable when exposed to heavy shock

I love guys who can watch a video of LiPo enduring an absurd amount of shock, beating, smashing, pulverizing into ripped shreds of cell between asphault and a 24" wrench, not do as much as get warm or make a puff of smoke, and then make a blanket statement like "LiPo are unstable when exposed to heavy shock."

There are all different types of LiPo. BMS battery has the most dangerous cells I have ever tested from anywhere. Other types of LiPo can be stabbed and crushed and shot and pounded and grinded against a grinder shooting sparks, overcharged, over discharged, shorted, and not do as much as make a puff of smoke or even get warm.

It's like playing with gunpowder, having it burn, and then declaring powders are dangerous, when some are as dull as beach sand, though they my outwardly look identical.

[RallySTX]

Yea Green, more pics of the girl! That one's a keeper. Anytime a chick will stay level headed enough to finish the date with a guy that nearly got her boobs burned off is golden! Better hang onto that one! Glad you guys are unharmed, but don't be surprised if johnny law tracks you down about the unauthorised campfire in the park!
Brian L.

[liveforphysics]

Also, the cell in that above video was dropped into a tub of water after being ripped open on all sides with the layers all open and exposed.

Guess what happened??? It gently fizzed for about 30 seconds, kinda like opening a soda. That was it.


If you strike a cell from BMS battery with a wrench, that sheeet starts bursting white smoke, and then catches fire.

[EBJ]

Lipo are unstable when exposed to heavy shock

I love guys who can watch a video of LiPo enduring an absurd amount of shock, beating, smashing, pulverizing into ripped shreds of cell between asphault and a 24" wrench, not do as much as get warm or make a puff of smoke, and then make a blanket statement like "LiPo are unstable when exposed to heavy shock."

There are all different types of LiPo. BMS battery has the most dangerous cells I have ever tested from anywhere. Other types of LiPo can be stabbed and crushed and shot and pounded and grinded against a grinder shooting sparks, overcharged, over discharged, shorted, and not do as much as make a puff of smoke or even get warm.

It's like playing with gunpowder, having it burn, and then declaring powders are dangerous, when some are as dull as beach sand, though they my outwardly look identical.

How do Turnigy and Zippy cells compare in your opinion?

[liveforphysics]

Lipo are unstable when exposed to heavy shock

I love guys who can watch a video of LiPo enduring an absurd amount of shock, beating, smashing, pulverizing into ripped shreds of cell between asphault and a 24" wrench, not do as much as get warm or make a puff of smoke, and then make a blanket statement like "LiPo are unstable when exposed to heavy shock."

There are all different types of LiPo. BMS battery has the most dangerous cells I have ever tested from anywhere. Other types of LiPo can be stabbed and crushed and shot and pounded and grinded against a grinder shooting sparks, overcharged, over discharged, shorted, and not do as much as make a puff of smoke or even get warm.

It's like playing with gunpowder, having it burn, and then declaring powders are dangerous, when some are as dull as beach sand, though they my outwardly look identical.

How do Turnigy and Zippy cells compare in your opinion?

All their modern stuff is 3rd generation formulas. This is why you see the ~3.85v nominal voltage rather than 3.7 of the early generations. We have had folks here who dropped a LiPo pack, and had it get hit by a car at speed, picked it up, and it still worked fine despite being flattened out. lol In one of my recent LiPo test videos, I take an over-charged 6S 40C Turnigy LiPo pack and stab it with the sharpened tip of a 30lbs 4ft chunk of steel multiple times as hard as I can. It made a cloud of white smoke, but I was very disappointed to have it never flame up or even get hot enough to do anything impressive.

Everytime I test the more modern packs, they blow me away with the amount of overcharge they safely take, how they handle shorting by just instantly and harmlessly popping the cell tabs, and the absurd amount of physical abuse they can take without doing anything dangerous to the user.

However, you can still always make them blow with extreme overcharge. Some of these modern RC cells take like 6.5v before they go though! A tip for folks doing it, you will watch voltage rise very slowly while it's actually still storing the charge, then around 4.8v you see voltage start to climb quickly to about 6-6.5v, then it starts to pull down voltage, and when voltage starts dropping down again, this is when it's about to blow up, generally around 5.4-5.7v for most cells before they erupt into flames.

[Green Machine]

LFP, thanks sincerely for all the thoughtful insight.

Its simply amazing when you start sharing all the data you got on lipo batteries.

[RoadShear]

All their modern stuff is 3rd generation formulas...

I know the 40C packs are the modern stuff, but do you think that the 6S 20C Turnigy/Zippy pack also contain the 3rd generation formula?
I have a 20C pack that I inadvertently discharged down close to 2.3V per cell and the pack seems a bit bloated.

Other than that it was working fine, just like before. Is it ok to not un-puff them and just use them as is?

Is the threat of cells getting into thermal runaway still very real when charging an over-discharged pack?

[parabellum]

I know the 40C packs are the modern stuff, but do you think that the 6S 20C Turnigy/Zippy pack also contain the 3rd generation formula?
I have a 20C pack that I inadvertently discharged down close to 2.3V per cell and the pack seems a bit bloated.

Other than that it was working fine, just like before. Is it ok to not un-puff them and just use them as is?

Is the threat of cells getting into thermal runaway still very real when charging an over-discharged pack?

Have hardly tried to get something spectacular out of 3cells from 4s 5A 20C-30C turnigy headcase pack (cheapest stuff you can get on HK). They was fully charged and I hammered hardly on them (using heavy steel hammer) 2 cells just got really hot and only 1 was a kind of success after punching few hols with narrow side of the hammer. I lot of smoke and heat from the last one (it was in the night and plates was pink after smoke was gone), but no visible fire.

[GCinDC]

LFP, thanks sincerely for all the thoughtful insight. Its simply amazing when you start sharing all the data you got on lipo batteries.

+1

[Green Machine]

Get this thread back on track...

Here is best pic i have of her obviously at animae festival in san diego this year.Oh she is big into japanese animae. And video games....kids.

[liveforphysics]

Get this thread back on track...

Here is best pic i have of her obviously at animae festival in san diego this year.Oh she is big into japanese animae. And video games....kids.

If you need some help handling things, you let me know bro.