huge lipo fire , not cool

15s turnigy 15s2p 5ah pack from hk, bout 2 years old aparently properly balanced, has not been charged in a week. bout an hour after charger was plugged in , exothermic dischage, scary as hell!! he was charging in his basement, which i did not recommend. luckily we were there too be as scared as we were. if it had happened at night there may well have been casualties.

Im not taking this lightly. I have been complacent with these batteries for along time. I charge in my apartment, and i charge at work( large dept store) this is over now, i cannot afford to be fired for making huge fireball and smoke at work/

my new endevour is to create an anti theft sytem for ebikes/bikes

Im done with commercial lipo applications. our legal system wont handle it im very sad

i will post pics in morning. watch out kids . very scary smoke

My batteries don't get charged at work. At 15 miles round trip, I have enough capacity so I don't need to worry about an overcharging event.

Are you sure you didn't have enough preventative measures so this wouldn't happen?

Bummer, LiPo fires keep popping up. Was the charge process using a proper RC balance charger or was it bulk charged. More details please. The fire must of been scary as hell.

Haven't you heard? Lithium polymer batteries are no more dangerous than any other kind of batteries. Just ask anyone around here.

That's pretty scary! Have you determined any possible cause yet?

How did you charge? Was it with a balance charger, or bulk? Are you sure the pack wasn't drained while sitting the week? Did you check cell voltage and balance before charging?

I'm not trying to place blame, just wondering what could have caused this.

Chalo said:

Haven't you heard? Lithium polymer batteries are no more dangerous than any other kind of batteries. Just ask anyone around here.

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Ha.
I have a feeling there are a very large portion of people here run them though, over 60%.
I'd say that the amount of people following the golden rules ( things that even me and dogman would universally agree on ) who have RC Lipos is under 10%.

Pair that with the most dangerous chemistry money can buy and yeah... yeah... it's sort of like how people keep running powerful hub motors on front aluminum forks and breaking their forks. Not everyone is going to get the memo.

It sucks and it bugs the crap out of me to see things like this. We need a good alternative to RC Lipo, yesterday.

And to hydro-one, sorry to hear about you and your friend's experience.

ouch. subbbed. more info pls,

Yes we need more info as it will help other avoid what not to do. I find it if you use lipo everyday, you can monitor it and maintain it. As for lipos I don't use, I make sure they are in storage mode and disconnect everything. I check on them monthly just to make sure nothing has gone down too much.

Going lipo is a big responsibility. Everyone using lipo need to understand there is a cost to using them.

More info would be good.

My major worry with any lithium battery used on an ebike is the standard of construction, wiring, etc. We're DIY'ing this stuff from raw components, and with the best will in the world we are going to end up with packs that may well be less reliable than some commercially manufactured and tested packs.

Also, we can all fall foul of missing something quite dangerous when we build a battery pack (using any chemistry), just as I did a few years ago, and end up with a dangerous fire and/or explosion: http://endless-sphere.com/forums/viewtopic.php?f=14&t=3241&p=47328#p47328

Any type of battery can and will explode or catch fire when being charged, all need proper care and attention to detail and high standards of construction in order to be reasonably safe. There is no such thing as a safe secondary battery, no matter what compounds it uses, be they lead, lithium, nickel or any other material. precautions need to be taken with all of them to reduce the risk of fire or explosion.

If you have any concerns about your ability to build a safe, robust battery pack, then make sure you always charge it somewhere where a small explosion of fire won't cause serious damage. Even if you do have confidence in the way you've built a pack, I'd still be inclined to always charge it in a safe place. My error only came to light after the fire, when we collectively pieced together the most probable failure mechanism, something I'd overlooked and which wasn't at all obvious at first.

Jeremy Harris said:

More info would be good.

My major worry with any lithium battery used on an ebike is the standard of construction, wiring, etc. We're DIY'ing this stuff from raw components, and with the best will in the world we are going to end up with packs that may well be less reliable than some commercially manufactured and tested packs.

Also, we can all fall foul of missing something quite dangerous when we build a battery pack (using any chemistry), just as I did a few years ago, and end up with a dangerous fire and/or explosion: http://endless-sphere.com/forums/viewtopic.php?f=14&t=3241&p=47328#p47328

Any type of battery can and will explode or catch fire when being charged, all need proper care and attention to detail and high standards of construction in order to be reasonably safe. There is no such thing as a safe secondary battery, no matter what compounds it uses, be they lead, lithium, nickel or any other material. precautions need to be taken with all of them to reduce the risk of fire or explosion.

If you have any concerns about your ability to build a safe, robust battery pack, then make sure you always charge it somewhere where a small explosion of fire won't cause serious damage. Even if you do have confidence in the way you've built a pack, I'd still be inclined to always charge it in a safe place. My error only came to light after the fire, when we collectively pieced together the most probable failure mechanism, something I'd overlooked and which wasn't at all obvious at first.

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Starting off with maybe the cheapest lowest quality made li ion batteries then stacking them together ?

I say leave those HK low quality batteries alone except for rc racing where you are not stacking so many together.

And pyro Luke at the race track

Yeah, 10% using lipo and actually following the rules might be close to the truth. Wouldn't be so sure I'm in the 10% myself. But I try to treat it just like I treated the propane systems in a hot air balloon. Like carelessness could kill you.

I'd love more explanation of what rules were or were not being followed. Knowing whether you overdischarged at some point or not is one big pitfall. Pop it back on the charger, and you might never know you killed a cell if it doesn't puff. Then there you are running a bulk charge, 5s or 25s it doesn't matter, and theres that 1v cell in there.

Two year old packs have a big potential for having gotten mechanical damage along the way. My about to retire, 2 year old 72v pack has taken a few knocks, lots of just crashing the bike, a few times I've dropped packs, and lots of tape covering spots where the shrink was chafing in the box.

dogman said:

Yeah, 10% using lipo and actually following the rules might be close to the truth. Wouldn't be so sure I'm in the 10% myself. But I try to treat it just like I treated the propane systems in a hot air balloon. Like carelessness could kill you.

I'd love more explanation of what rules were or were not being followed. Knowing whether you overdischarged at some point or not is one big pitfall. Pop it back on the charger, and you might never know you killed a cell if it doesn't puff. Then there you are running a bulk charge, 5s or 25s it doesn't matter, and theres that 1v cell in there.

Two year old packs have a big potential for having gotten mechanical damage along the way. My about to retire, 2 year old 72v pack has taken a few knocks, lots of just crashing the bike, a few times I've dropped packs, and lots of tape covering spots where the shrink was chafing in the box.

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The rules may work for batteries without defects but making up rules for HK lipo with defects ?

How do you do that ?

hk ships batteries with bad cells from the start.

And they are not easy to change out.

Why do we mess with this junk ?

In the whole other bicycle world the bicycle kids are proud of their high quality parts on their bikes ?

I see so many cool bike builds on this forum then they put cheap ass hk lipo on it ?

Has anyone tried these ?

http://www.allerc.com/hyperion-g3-vx-5000-mah-10s-37-0v-35c-65c-lipoly-split-pack-p-5118.html

I think these fires are bad for the whole ev movement and suggesting using hk lipo on evs is bad for the whole ev movement.

And I sure don't understand why the #1 ebike forum would have so many people getting on here and suggesting people use hk lipo.

I wonder how many people gave up on ebikes because of a bad hk lipo time.

Surely they don't all post about how they almost burned down the house because they did not do the lipo rules !

dogman said:

Yeah, 10% using lipo and actually following the rules might be close to the truth. Wouldn't be so sure I'm in the 10% myself. But I try to treat it just like I treated the propane systems in a hot air balloon. Like carelessness could kill you.

I'd love more explanation of what rules were or were not being followed. Knowing whether you overdischarged at some point or not is one big pitfall. Pop it back on the charger, and you might never know you killed a cell if it doesn't puff. Then there you are running a bulk charge, 5s or 25s it doesn't matter, and theres that 1v cell in there.

Two year old packs have a big potential for having gotten mechanical damage along the way. My about to retire, 2 year old 72v pack has taken a few knocks, lots of just crashing the bike, a few times I've dropped packs, and lots of tape covering spots where the shrink was chafing in the box.

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I'd second all that, but add that it's not just those using lithium cells that need to watch out. My fire and explosion a few years ago (the one in the link above) was with NiMH cells, reasonably good quality Tenergy cells, supplied from a reputable UK vendor.

My main worry with DIY packs is the sort of unseen damage that occurs after a period of service. Bikes take a fair few knocks and bumps, and it doesn't take much to cause subtle damage that can store up problems. One thing that's happened to me twice now is having a balance wire break off inside LiPo packs. I'm getting the point now where I'm thinking of stripping down any HK packs and reassembling them with known to be good connections. The cells themselves are OK, once you've weeded out the inevitable runts that seem to occur from time to time, but the assembly quality isn't that great, particularly on the Turnigy packs, I've found (for some reason the Zippy's nearly always seem better).

Probably worth bearing in mind that we are dealing with products here that, in the main, seem to have little or no quality assurance. The onus is on us to do that, as best we can, when we use them to build a pack.

And I'll continue using cheap ass HK lipo. If you want to buy into all that hype, you pay $2 per wh for it. I'll stick with under $.50 per wh. It's perfectly suited for 5C ebike use.

Ok , thanks for the replys guys. here are some pics.

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the cells were inside an al enclosure (luckily, otherwise the bike would be ruined and the house would likely have caught fire. it was fairly well contained, but was shooting out like a blowtorch for about 6 minutes. the smoke was BAD BAD. I went into the house thinking i might die, i was checking the rooms for kids sleeping, i coulndt see anything, i was bumping into walls, just feeling around with my hands, the lights were on but its was dark as underground. The basement was completely filled with smoke, i took a couple breaths of it and i actually almost went down in there. wild

So the enclose was lined with neoprene like rubber mat. He said he checked the cells a week ago or so and they were perfect. as they always have been, packs never been balanced in prob 400 cycles or more. he said they were never more than .08v out. The pack was made with three pairs of 5a 5s turnigy 20c/ . permenently connected packs in parrelel, then strung in series for 15s 10ah pack

bulk charging with meanwell 7 amps. we have the charger and i will be checking the output voltage when i get there again. (first thing that might have happened). He carries the charger around in a backpack so it may have got damaged (and i had removed the zener z1 if anyone knows what im talkin about ) (EDIT the charger tested right at 62.5 volts , so it wasnt this)


he claims the bike was not plugged in during sitting for a week. and had been used regularily until then. so im thinking its either a "charger" problem or a dented cell that went to 0 over that week.


DO NOT CHARGE IN HOUSE TRUST ME, the smoke and fire is INCREDIBLE, and this was only a small bike pack

I guess if you have the time you could rebuild them.

It was taking a nanotech lipo battery apart to fix it that made me never want to touch one again.

Worst quality pack build I have ever seen and I have taken 100's of battery packs apart.

I could not believe it could be legal to ship something like that in the mail ! ! !

Then to suggest others buy them and stack them on an ebike ! ! ! Bad news ! ! !

A bms likely would have prevented this. There was a LVC on the controller at around 3.7 per cell.(pack level lvc)
A bms or balance charging setup is in my future. Selling lithium packs is not. Now i understand and it is very clear to me that if this was your car (EV) in your garage, you might well wake up dead. be careful kids, Im from the LPF school of batteries, charging under my pillow and all that. after seeing this i wont be taking chances again. GOLDEN RULES.

wesnewell said:

And I'll continue using cheap ass HK lipo. If you want to buy into all that hype, you pay $2 per wh for it. I'll stick with under $.50 per wh. It's perfectly suited for 5C ebike use.

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Do it and enjoy but to get online and say it ? ? ?

If the good Hyperion lipo lasts 4 times as long then it is cheaper ?

Have you ever tried quality rc lipo ?

That was a stroke of luck, together with the way the battery box helped contain the fire, that saved the house. I guess that, like me, charging inside the house is now going to be a complete no-no...................

No easy way of telling what the cause was. One cell could have died, an internal short could have developed, could be pretty much anything after a fair period of use. Given what I've seen in a couple of my older packs, my money would be on a mechanical fault having developed, maybe a chafed or broken connection or a bit of wear from movement allowing cells or connections to short.

Thanks for posting the photos. they're a useful reminder for people to take care of these things. Heck, it's even made me remember that I've had a big box of new LiPo packs in the spare room since they were delivered a couple of weeks ago. I've just taken them out and put them where they can't cause any harm, inside a metal shed, well away from the house.......................

Wow, that wasn't as tragic as i thought it would be.

I think that the 28 packs i have wouldn't fare so well though.

It was reading posts on this forum that got me to buy some nanotechs from HK.

One came right away with a bad cell.

So we took it apart and saw the way it was put together.

The worst battery pack build I have ever seen.

Made me think the ES kids don't know much about batteries.

Still does.

Also makes me think that on my worst soldering day I could do a better job putting a battery pack together.

So, get your 11 year old son a soldering iron and let him solder up a pack for you.

I bet he could do a better job than the hk battery building kids !

Good thing it was in a metal box. The fire ball would of been huge in an enclosed area.

I always balance charge, bulk charging is very much like the early RC days. Too many fires, that is why the RC industry created balance chargers to deal with the fire issues. I would never bulk charge, you run the risk of charging without knowing the health of the pack. I've been very happy with the Hyperion chargers, they will flag and shut down the charge process if any errors are detected. You can see the cell voltages per paralleled bank during the charge process. I usually check this during each charge cycle to see how my packs are doing before walking away. I have 2 banks that are always lower than the rest, but not by much. They quickly charge up to speed with the rest, but I know they will probably be replaced over time. I need to fully enclose my setup this winter, been pretty lax lately with lipos.

Charging such big packs in the house is a bad idea. You might be able to contain the fire, but the smoke damage is just as bad as having a fire. The stuff is corrosive as well and will take you months to cleanup. I charge mine in the garage, I can open the garage door if a fire does break out. The damage to things will still be very costly, but the house will still be livable.

Ideally, outside in a metal shed would be best. Very few of us have such options. Be safe.

still no info to use to analyze how the fire started. at least with the fire chroot reported we had some closure and understanding that it was a short.

since this is a metal box, it has to be analyzed to see if there is somewhere inside that indicates that the cells might have shorted out to the box initially to provoke the thermal runaway if that is what it is. if there was foam inside the box, it might have ignited itself initially too.