Headway battery pack FIRE! <lot pics>

[chroot]

Headway 40160S LiFePO4 battery pack [16S and 16Ah]

Hi, Our daughters ran to our master bedroom while we were chatchit. They alerted us, shout "FIRE FIRE FIRE" and my mind was "oh shit". I ran to the garage, I saw the headway pack was on fire, I hurried pull the Yuba Mundo cargo bike to outside, I pulled the wool jacket attempting put out the fire, I wrapped the wool jacket on my hand and pushed the battery pack off the Yuba bike.

Fortunately No damaged to the house or garage. Minor damaged to the Yuba Mundo cargo bike. We are fine and bummed the incident. The BMS caused start the fire and possible shorted?

I will post the picture later.

 

[Punx0r]

That's not good At least no one was hurt and the fire didn't spread, causing more damage.

 

[Jason27]

Wow. Did you wire the pack or did you buy it from China?

 

[dnmun]

sounds like the charging mosfet overheated and caught the pcb on fire.

i am sure they will use this as proof that lifepo4 catches on fire when overcharged like the bogus story about gregg's garage catching fire because of lifepo4 overcharging.

 

[liveforphysics]

sounds like the charging mosfet overheated and caught the pcb on fire.

i am sure they will use this as proof that lifepo4 catches on fire when overcharged like the bogus story about gregg's garage catching fire because of lifepo4 overcharging.

Charging mosfet overheated and caught the PCB on fire? Seriously dude? The solder will all melt right off the PCB before the PCB catches fire. You have to hold a torch on a PCB continuously to burn it, and they extinguish the moment you take the heat away. Wiring short seems likely, of if it was a 2p (or more) pack, possibly had a bad connection somewhere so a single cell ended up trying to eat ~30Ah of charge (or whatever) rather than just 15Ah (or whatever).

Headways have burst into flames before during charging (or just over-temp), along with A123 cells (round and pouch) etc. Just because they don't easily liberate the Oxygen from the bond with Phosphor doesn't mean the other 90% of the cell isn't made with flammable solvents/electrolyte and separator, carbon black, etc. Just because a portion of the active coating material in the cathode doesn't easily liberate oxygen doesn't mean the rest of the cell can't catch fire and burn.

 

[deVries]

What was the state of charge? Charging? Just charged? Pack low/high or ? Everything "off" & disconnected?

How new is the battery? When purchased/built? How many cycles now?

Thanks.

Good thing your kids caught the fire.

Seems like having an easily removable battery pack when not riding in safe storage is a great safety option.

 

[dogman dan]

I'm very interested in the rest of the story. A hot bms could easily catch other materials on fire. Anything else nearby, foam padding or such?

 

[chroot]

I am back.... Sorry, I went bed for work today in 3AM morning and I'm exhausted.

My battery pack wasn't on charging at all. It's been reliable since like 6 mos or so. Somehow, It must gotten a shorted and the BMS was throw flame and battery cells threw flame out too.

I don't know how it happened. I got everything picture resize and going upload to ES.

*OP updated include the pictures*

----
I bought from ES member. The battery pack was like 2 mos old.

Wow. Did you wire the pack or did you buy it from China?

----

The battery pack was about 80% SoC and It was off (I am using the kfong smart switch). I rode less 2 miles after full charged.

What was the state of charge? Charging? Just charged? Pack low/high or ? Everything "off" & disconnected?

How new is the battery? When purchased/built? How many cycles now?

Thanks.

Good thing your kids caught the fire.

Seems like having an easily removable battery pack when not riding in safe storage is a great safety option.

 

[deVries]

Wholly Crap BattShit!



1) Removable battery in safe storage w/no bms.

2) Charge with auto-turn-off timer *and* HVC single cell auto-power-off too. Audible alarm for HVC & smoke alarm, as a another 2nd warning system.

3) Even better than "2 above" or bulk charging or using bms is to charge individual cells only for maximum safety. Do a charger setup like Jeremy Harris did with DC/DC single cell chargers, or use the VoltPhreaks for A123 type chemistry at 3.65v.

So sad this happened to you, but thankfully you can come back stronger/safer from just these battery ashes.

Thanks for sharing... Sorry for this happening...

 

[liveforphysics]

I want the pictures!!! Pictures I say!

 

[999zip999]

Sell the pic's to LFP you might get enough for a battery. You're very lucky it could have been a lot worse a lot worse. Sorry for your lost. Good to hear nobody got hurt.

 

[chroot]

@deVries - The battery pack protected by the Topeak MTX TrunkBag DXP and it was destroyed.

@Luke - It's in OP with lot pictures

I want the pictures!!! Pictures I say!

 

[Alan B]

Wow. Glad the damage was not worse.

How's the kfong switch? Did it get burned?

Where was the BMS from?

What was the last thing that happened to or was done to the bike/pack/etc?

Old type PC boards were quite flammable. Modern boards are fire resistant. Wonder if some cheap PC boards are made the old flammable way.

It would be really good to figure out what started this fire. If that is possible.

Regards,

 

[Alan B]

Do you have some good "before" pics showing how it was all set up before the fire?

 

[chroot]

kfong smart switch is fine none damaged and The MPIII main connector near the top of yuba frame/seat post that where the kfong smart switch sitting. The battery pack sat on top of cargo behind the seat. You can see the back of seat and top of cargo frame burned that where the battery sat. I surprised the seat (it was from iZip) seems true fire resistant.

The pack handmade by Jim Delgado from Washington state (ES member told me where he bought from) and it was very reliable excellent built pack. I mean he is very professional excellent job. I gotta digging find old picture before and after. I'll post once I find it.

The BMS was sitting on top of battery pack and The kfong smart switch is pretty darn reliable and it has auto-shut off within 30 mins. My MPIII throttle has the indicator power leds would light out when the auto shut off by kfong smart switch. It has do with either battery or BMS shorted somehow. I can't figure why it happened.

Wow. Glad the damage was not worse.

How's the kfong switch? Did it get burned?

Where was the BMS from?

What was the last thing that happened to or was done to the bike/pack/etc?

Old type PC boards were quite flammable. Modern boards are fire resistant. Wonder if some cheap PC boards are made the old flammable way.

It would be really good to figure out what started this fire. If that is possible.

Regards,

 

[dnmun]

man, this may sound unfair, but i bet you were the best person who coulda had this happen to.

very good documentation, not only did you respond in a timely and effective manner but the pictures i think hold the clues. especially look for scorch marks which were earliest in the fire.

really good pictures, there is wire that goes from the junction to the red at the controller spliced to the charger lead. that wire runs over the top of the BMS and has frayed and burned open.

there is a spot on the right frame rail where there are little spittels of metal or debris from the plastic. wondered what you think that is and where was that wire originally when the battery was packed int he bag. where did that wire run with respect tot he frame rail?

maybe you can auction off the photo rights so people can use them on their avatar. interested in what you think might have happened. also how much of the contents of the cells was boiled out into the fire from the rupture of the the cells? do any of them have any charge left after shorting out to each other as the plastic melted off of them.

a very sobering realization of the way batteries are assembled with plastic separators. is a nomex sleeve next?

thanks and our deepest and most sad looking at a dead pack sympathies, but best pictures ever!

 

[deVries]

maybe you can auction off the photo rights so people can use them on their avatar.

$1 :lol:

Btw, LFP is making fun of the fact some of the pics in the 1st post are not formatted for in-line viewing, so some pics need to be shrunk down to view in the post. See my post where I reformatted the flaming batts pic to view within my post.

Nice live-action photography, btw.

 

[Alan B]

Was there a main fuse between battery and BMS?

 

[chroot]

No, its between 1st cell's positive to the main lead with fuse connect to the kfong smart switch.

Was there a main fuse between battery and BMS?

Sent from my Amazon Kindle Fire using Endless Sphere

 

[chroot]

Lol, actually I scaled down from 8 megapixel (3264x1952) to under 640x480 size bit lower.

It is not formatted for inline.

$1 :lol:

Btw, LFP is making fun of the fact some of the pics in the 1st post are not formatted for in-line viewing, so some pics need to be shrunk down to view in the post. See my post where I reformatted the flaming batts pic to view within my post.

Nice live-action photography, btw.

Sent from my Amazon Kindle Fire using Endless Sphere

 

[liveforphysics]

I like the pictures. You took some great shots while it was burning.

In my headways testing, it only took 4 cells in series getting shorted before the weakest cell reversed polarity after about 30 seconds, boiled juices out of the side of the can, and burst into flames fueled by spraying solvent. I would imagine with 20cells in series, if the wires did short to the frame, it could happen pretty quickly to the strings weak cell.

Can you see metal pitting or signs of arcing on the steel frame itself? I found with my various LiPo pack wiring shorts on deathbike that the steel gets pretty large pits eaten out of it nearly instantly from a healthy short.

 

[iperov]

headway is just named "china noname", why quality must be higher?

 

[circuit]

I doubt this is caused by headway cells.

What was done wrong:
1. cells were packed without special plastic tray, separating the cells from each other. (?)
2. balancing wires were made of cheap materials. High temperature insulation must be used in places like this. It could be a teflon coated wire (600°C) or silicone (300°C) at least.
3. there were NO fuses on every balancing wire near the cells. These prevent fires due to shorted balancing wires.
4. other wires were cheap as well.

I am not making these rules, its official.

I have no idea what the 'kfong smart switch' is, but I doubt it has anything to do with security.

I guess that the fire started due to shorted balancing wire or, more likely, damaged cell insulation (two cells shorted to each other). Very common in "ductape" packs.

 

[Lyen]

Hi Chroot,

I'm glad you are okay. It was as devastating as my last battery fire incident.

I have found some original photos of the battery for Chroot since he originally emailed me for suggestions a while ago.

Here are the pictures of the exact battery at the time Chroot picked it up from another member:

I suspect the reason it was caught on fire was because the brackets designed to hold the cells were way too close between cells.

If you look at the last photo, the blue coating/jacket of the cells are actually partially/nearly touching each other. When being used on the bike, the bounciness will have the potential to cause the cells rubbing against its neighbor cells and then thinning the blue coating. Once the blue coating is thinned to the point and exposed, the side of the cells are become conductive. When it happen, it will possibly shorting the neighbor cells and create excessive amount of heat. It then render explosive gas and cause fire.

For anyone using the Headway battery, I would recommend to verify the blue coating of the cells to ensure they are intact.

Although BMS is generally pretty safe, but allow me to share my experience with the BMS the same one that the ops used. Chroot had also stated the BMS being used was the Signalab. The common MOSFET transistors being used on the Signalab are the Fairchild ST 60NF or the 75NF. These MOSFET transistors indeed generate a lot of heat. I've learned it the hard way by burning my fingers while touch the MOSFET at the time the LifePO4 battery pack was being charged. :| I was told there are newer designs (multiple versions) with more MOSFET, which help reduce the temperature during use or charge. Anyway, it would helps to leave the BMS with room the breath during charge.

Regards,
Lyen

 

[circuit]

Damn, so there was a plastic tray... too bad it melted right off. This should be made from better material...