Nasty LiPo fire

[neptronix]

The packs wer Zippy 20C packs, brand new, and balance charged on a high end Hyperion charger. This was however their first discharge cycle.

This is what I was talking about...if there was a QC issue, it would probably have been spotted if the packs had been cycled a few times off the bike........seems like complacency to me - everywhere I look that is the standard wisdom....

I wish it was standard wisdom. I have been trying to drill this into people on the forum for months. But not because cells can catch fire, but because the QC is bad on hobbyking cells and you get an occasional dud that can overdischarge and lead to puffing / fire later on.

 

[Ypedal]

I don't think i would even assume that QC at the factory is bad, however it may possibly be time limited/rushed to shipping..

The cels have little white stickers with 2 x mah readings, usually something like for example " 5100 ~ 5020 " i ASSume that those are capacity tests at the factory, so they do go thru at least a few cycles before they assemble and ship the packs obviously..

Now, very small imperfections may/could take weeks to show up.. by this time the packs are built, shipped and reshipped before we get them, in some cases they may spend weeks/months on the shelf before the shipping guys box them up.. shipping pickers don't typically do QC stuff, they take from the shelf and box it..

a lot of ASSumptions here, i know nothing for certain...

also, we can only assume what could have happened in Kepler's situation, was there a pebble on the floor under the pack jabbing into the cells while the bike was worked on ? could be as simple as a tiny bit of solder on the top of the circuit board that got loose, the ballance wires might have gotten crushed and shorted out causing a chain reaction.. all things that have nothing to do with the cells themselves.

 

[neptronix]

Good points, but regardless..
There seems to be a 10%-15% defective pack ( low/dead cells, puffed cells, etc ) rate once the item is received, that's a problem. I think we really need to think of the packs as defective until proven otherwise.

 

[liveforphysics]

During testing of my bike last night, the pack was bouncing around because we didn't strap it down the last time we put it in the tray. It bounced back a bit and rubbed on the tire, right through the plastic hard-case, through the foil pouch, and right into a cell's guts! The pack behaved totally normal, no issues, and we removed the damaged pack from the battery.

Grinding right through the side of a pack into the guts of the cell, and no smoke or fire or anything.


I think it has to be a contamination thing that causes the random fireballs.

 

[ZOMGVTEK]

My friend informed me a few days ago his garage was filled with smoke from some sort of battery fire...

Turns out it was just a residual issue involving damaged balance wires. A day or two earlier, he was charging his 24S2P pack at 6S2P x 2, and he left one of the parallel balance harnesses connected as he connected the 24S2P connector. This, of course, resulted in melting the tiny balance wires. He did nothing about it, and continued to use the bike. It was sitting in the garage for a day or two, until someone noticed smoke in the garage at 5AM. Turns out it wasn't really a big deal. I cleaned up the packs, all appears to be well. They just need 2 new 4mm HXT's and 6S balance plugs. The cells appear to be fine, the other pack was unaffected.

 

[knoxie]

I have to admit I did exactly the same thing when I first got my packs too!! fried the balance wires in a second! did a repair on them and they are still working like trojans, my new booster pack has really helped me extend my range, took it out today so nice to burn 13AH at 50V here is my charging setup complete with my booster chargers.

[youtube]brKpkZN2xpo[/youtube]

 

[liveforphysics]

Here is the pack that we didn't strap down, it bounced out of it's cradle and rubbed on the tire right into the alternating annode/cathode layers of the pack, and didn't make any smoke or heat or a fuss of any sort. Now, I consider this to be getting very lucky, don't go thinking it's OK to just grind into your packs and never have fireworks.

 

[knoxie]

:lol: its funny Luke when i was looking at the pictures of the frame earlier the one thing that struck me was how close the packs were to the back wheel he he you were Lucky that could have been very messy :? like I said you have to do a lot to these cells to start a fire, i am pretty sure what we have seen so far is a qc issue, it certainly wont change what I am doing as I got my back covered any old how, so did you get round to posting the videos

 

[liveforphysics]

so did you get round to posting the videos

Which videos do you mean my friend?

This one with my new bike build in it:

[youtube]oKuU6JahL5w[/youtube]

Or this new battery-fun video I made?

[youtube]LExMC5buoFg[/youtube]

 

[knoxie]

8) sorry Luke I didnt check your other thread, I meant the one with Cedric in it, I have seen it now and its the coolest thing, damn! ha ha Cedric is a pure genius, I used to read with envy over 12 years ago now about his little bike and his escapades with it, then the journey with the motors and how he got ripped off as well, great shame for such a top bloke, I wish him all the best with the Agni, the Lemco business left a rather bad taste in the mouth I am sure.

I am off to meet Jozzer next weekend down in Brighton all being well, deec is picking up his new bike dont tell anyone but I am making the journey on my XT Yamaha stinker! ha ha, the ev revolution may have to wait a little whilst I figure out the 220 mile round trip on a motorbike in one day battery pack! ha ha

 

[Kepler]

Firstly no offence taken in relation to how I may have contributed to this failure. I am much more interested in being part of the solution here and I think this thread has been in general, very constructive.

Although I agree complacency has crept in when it comes to safe storage of my LiPo's, I dont think complacency had much to do with this failure. I think a bit naivety certainly played a part though. If anything, I am more confident with handling LiPo's since this discussion.

 

[liveforphysics]

Firstly no offence taken in relation to how I may have contributed to this failure. I am much more interested in being part of the solution here and I think this thread has been in general, very constructive.

Although I agree complacency has crept in when it comes to safe storage of my LiPo's, I dont think complacency had much to do with this failure. I think a bit naivety certainly played a part though. If anything, I am more confident with handling LiPo's since this discussion.

That makes you a bad-ass guy Kepler!

 

[JohnC]

.

 

[jonathanm]

Firstly no offence taken in relation to how I may have contributed to this failure. I am much more interested in being part of the solution here and I think this thread has been in general, very constructive.

Although I agree complacency has crept in when it comes to safe storage of my LiPo's, I dont think complacency had much to do with this failure. I think a bit naivety certainly played a part though. If anything, I am more confident with handling LiPo's since this discussion.

Thanks, Kepler. No offence was meant, and I was surprised anyone would take it that way....complacency is a very natural human trait....

Three things I see actually, in what you did - 1 not cycling the pack a few times and seeing if it behaves, 2 hooking up the untested pack *indoors*, and 3 having untested pack hooked up on an untested bike while troubleshooting the wiring......*while indoors*.

I did all of this stuff either outdoors or just inside the house with the door open, crapping my pants, in full on OTT safety mode, lol....it was so utterly uneventful that for my next pack I might not have bothered....your post is a good reminder that until you know a pack is ok for sure, there is a (very slim) chance of it going off....and even once you know its ok, there is a (very very slim) chance of it going off. So while there is any unknown variables, I'll be fiddling with my pack outside.

The main thing I have learned though, is never, ever say "I have a hunch it not going to even burn"...that's asking for trouble, lol

 

[Red_Liner740]

RE: Lipo Battery Electric Bike Charging Station Vid Description
Knoxie
I’m not following the math. I may have missed something. You have 6 bricks that are 6s 5ah. You say wired to get 50v 15ah. So 2 packs are wired in series for 50v (charged) and 3 wired in parallel to get to 15ah. That’s only 5 bricks. 12s3p

Good vid. Love the charger and power supply.

Hes math is right, yours is wrong.

3 in parallel does give u 15ah so that gives u 25v (charged) 15 ah pack, then u take two of those packs and wire them in series for 50v. 3Px2s = 6 packs

 

[liveforphysics]

The main thing I have learned though, is never, ever say "I have a hunch it not going to even burn"...that's asking for trouble, lol

Yes, I hope everyone learned from that line.

 

[JohnC]

.

 

[EBJ]

Hes math is right, yours is wrong.

3 in parallel does give u 15ah so that gives u 25v (charged) 15 ah pack, then u take two of those packs and wire them in series for 50v. 3Px2s = 6 packs

Who is Hes and what the f**k is u? Speak in complete sentences and maybe I can understand you, even though I didn’t ask you.

anything you post on a forum becomes a question, regardless of whether or not the sentence is followed by "?". If that wasn't the case we would have a lot of incorrect information floating around without anyone ever correcting it. Pointing out a mistake or miscalculation (even if done in a rude way) is still 100X better than letting it just sit there for someone else to make the same mistake. my .02

Another question: Has anyone "fire-tested" multiple packs of lipos at once... like 3 5S packs in parallel ? I would like to know if the cells burn one after another like they seem to do in individual packs, or if they all go up in flames together.

 

[liveforphysics]

Hes math is right, yours is wrong.

3 in parallel does give u 15ah so that gives u 25v (charged) 15 ah pack, then u take two of those packs and wire them in series for 50v. 3Px2s = 6 packs

Who is Hes and what the f**k is u? Speak in complete sentences and maybe I can understand you, even though I didn’t ask you.

anything you post on a forum becomes a question, regardless of whether or not the sentence is followed by "?". If that wasn't the case we would have a lot of incorrect information floating around without anyone ever correcting it. Pointing out a mistake or miscalculation (even if done in a rude way) is still 100X better than letting it just sit there for someone else to make the same mistake. my .02

Another question: Has anyone "fire-tested" multiple packs of lipos at once... like 3 5S packs in parallel ? I would like to know if the cells burn one after another like they seem to do in individual packs, or if they all go up in flames together.

Always one after another in my tests.

 

[amberwolf]

Here is the pack that we didn't strap down, it bounced out of it's cradle and rubbed on the tire right into the alternating annode/cathode layers of the pack, and didn't make any smoke or heat or a fuss of any sort. Now, I consider this to be getting very lucky, don't go thinking it's OK to just grind into your packs and never have fireworks.

http://img861.imageshack.us/img861/2743/packworn.jpg

http://img225.imageshack.us/img225/7858/packdamged.jpg

Meh, a little superglue and duct tape and it'll be JUST FINE. Just make sure you wash off the dirt out of the layers first with a high-pressure water spray. :lol:

FWIW, I have a couple of backpacks with bottoms I had to ziptie together in the middle, for the same reason. :lol:

BTW, that pack looks like it still has a few undamaged cells...gonna save them for fixing other packs with?

 

[wojtek]

inspired by this post, i took out 2x 3.7v 5400mah cells that were not performing anymore. I had a lot of guests for the BBQ yesterday. Wanted to impress them with lipo explosion.

First one i tried to ignite by hitting with a hammer. I hit it once , nothing. Second, nothing. Then feeling embarrassed, i kept hitting as strong as possible. Nothing. The cell just got hammer-damaged. Then i realized that I should have used a nail to pierce it. But i had impressions, on one of those videos you guys just hit it once with a hammer only and it was enough for the cell to catch on fire?

Second one - in more classy way - just overcharging. But didnt want to keep crowd too long to wait. So i took my Meanwell 24v63a and connected to this poor little 3.7 5.4ah cell.
Within seconds it got on fire. My pride was saved.

Videos were taken from mobile phones so i think i will post it but now it might be boring after the Luke's show.
To win Lipo-fire oscar award i think i have to do much better than that.

 

[liveforphysics]

BTW, that pack looks like it still has a few undamaged cells...gonna save them for fixing other packs with?

Nope, donating them to the fire Gods.

 

[Ricky_nz]

Nope, donating them to the fire Gods.

I wouldn't have expected anything else from you Luke :lol:.
Are you going to come up with some new creative/entertaining way to burn them?

 

[liveforphysics]

Nope, donating them to the fire Gods.

I wouldn't have expected anything else from you Luke :lol:.
Are you going to come up with some new creative/entertaining way to burn them?

I've got around 10 various packs that are damaged and need to be neutralized (with fire).

And sorry Amber, I would love to give them to you, but I won't ship sketchy damaged LiPo, it's not worth burning down a post-office somewhere or whatever. 4s packs from HobbyKing are like $24 right now and $0.01 shipping from the USA, so you can stock up for cheap.

 

[Ricky_nz]

I've got around 10 various packs that are damaged and need to be neutralized (with fire).

I'm sure you can come up with a way to burn those lipos involving a bike at 50+mph and the fire suit :lol:

Failing that figuring out a way to fire them out a spud gun while burning might be entertaining. :lol: