Liar Liar Pants On Fire > Thermal Runaway LifePO4 Ducktape

[Lyen]

The safety claim of the LifePO4 is a liar when duck-taped and caused my pants on fire.

I had an incident while I was riding my ebike home from work earlier in the morning. While I was traveling at 31MPH for the last 6 miles, there was a car driver shouting at me telling me my ass was on fire. I immediately pull over to the sidewalk and put off the fire with my motorcycle glove. Fortunately, only one of my finger had a minor burn on the skin when trying to put off the fire. My underwear had also saved my butt. LOL



The ducktape 48v 20Ah LifePO4 battery inside the Sunlite rack bag becomes a fireball and very much burned everything inside the bag including the BMS, Topeak tool, charger, and the rack bag.



It took me five minutes to put off the fire with a piece of ceramic brick I picked of the ground.



It then start investigate and noticed a few of the cells in parallel of are down to 0.1v. The BMS could not detect it and continue to discharge. The out of balance cells heated up the ducktapes and started the fire.



I was not able to take pictures of the Sunlite rack bag since it is totally burned to ash.



So my conclusion to the safety claim of using the LifePO4 is a liar if it is being wrapped with ducktape.



Lastly, my advice to the people using any ducktape battery should check their cells periodically if possible to avoid having the incident like I did.

Regards,
Lyen

 

[liveforphysics]

It can happen with non-duct-tape LiFePO4 cells as well. If you watch the vid in my sig, you will see a headways cell blasting out flames. Granted, it took a LOT of heat before it happened, but it still happened.

 

[maydaverave]

Where did you get the battery?

 

[wasp]

The safety claim of the LifePO4 is a liar when duck-taped and caused my pants on fire.

I had an incident while I was riding my ebike home from work earlier in the morning. While I was traveling at 31MPH for the last 6 miles, there was a car driver shouting at me telling me my ass was on fire. I immediately pull over to the sidewalk and put off the fire with my motorcycle glove. Fortunately, only one of my finger had a minor burn on the skin when trying to put off the fire. My underwear had also saved my butt. LOL



The ducktape 48v 20Ah LifePO4 battery inside the Sunlite rack bag becomes a fireball and very much burned everything inside the bag including the BMS, Topeak tool, charger, and the rack bag.



It took me five minutes to put off the fire with a piece of ceramic brick I picked of the ground.



It then start investigate and noticed a few of the cells in parallel of are down to 0.1v. The BMS could not detect it and continue to discharge. The out of balance cells heated up the ducktapes and started the fire.



I was not able to take pictures of the Sunlite rack bag since it is totally burned to ash.



So my conclusion to the safety claim of using the LifePO4 is a liar if it is being wrapped with ducktape.



Lastly, my advice to the people using any ducktape battery should check their cells periodically if possible to avoid having the incident like I did.

Regards,
Lyen

sorry about the bad luck edward but i'm glad you are alright...a little lighter in the wallet...btw who's battery ping,cammy ???
glad your alright

 

[dogman dan]

Looks like 18650's . Yeowch! Ida thought it would have taken a dead short to get one that hot. The other duct tape pack I recall getting that hot had rubbed a rough spot on a vintage scooters homemade battery compartment cutting into it till it made a short. No chemistry likes a c rate that high, so hot enough to set duct tape on fire can happen with any chemistry that gets shorted. I had a 12v truck battery melt every single wire under the hood and in the dashboard once. only 12v but it was shorted to the exhaust manifold.

Amazing that could result simply from having a few dead cells in the pack though! Time to add another thermometer to our bikes?

 

[slayer]

Ole f?$**&% sh*&%?...
That is bad.
you have the outside temp and continuous discharge and other info to share

 

[Lock]

Lastly, my advice to the people using any ducktape battery should check their cells periodically if possible to avoid having the incident like I did.

How`bout disassembling any duct tape pack completely when new and replacing all BMS sense wires w/better than eg 24 gauge... ensure all soldered joints and wires are mechanically and electrically "tight"...
lock

 

[number1cruncher]

You are having some bad luck with batteries this year Lyen. http://endless-sphere.com/forums/viewtopic.php?f=14&t=15261&p=226722&hilit=lipo#p226722 Maybe its all those big hills in San Fran stressing the batteries? Glad to see you're okay!

 

[TylerDurden]

I'm with dogman... Sure looks like a short to me.

Also, I would not call it thermal runaway if you could extinguish the fire. LiCo/LiPo would probably be an unstoppable raging blaze.

Most packs present a risk due to the level of energy they contain and most cells will heat and burn surrounding flammable material when shorted, regarless of chemistry.

 

[Hyena]

Wow, take that lipo haters!

While I was traveling at 31MPH for the last 6 miles, there was a car driver shouting at me telling me my ass was on fire.

Not to question your sexual orientation or preference of extra curricular activities, but what have you done to desensitise your ass to the point that you didn't know it was on fine ? :lol:

Seriously though it's good that you're OK and fortunate that the pack was far enough behind you that it didn't set your clothes on fire.

 

[johnnythefox]

Wow Lyen, sorry about your battery, at lest you havn't lost your sence of humor.

 

[Lyen]

Hi Wasp! The reason I did not disclose the name of the maker is because I do not want to do any harm to their business. Also, there is no real hard evident to proof if it was cause by short circuit or if it is the failure in the original construction and/or design. My only intend was to just wanted to let people know and expect the worst if something goes wrong.

 

[Hyena]

You're not having much luck lately Lyen, first the battery then the BMS.
I think you need to rename this thread to lyen lyen pants on fire :lol:

 

[Lyen]

You're not having much luck lately Lyen, first the battery then the BMS.
I think you need to rename this thread to lyen lyen pants on fire :lol:

Ha ha! I agreed! But I have to pay the "educational entry fee" or the learning lessons to join the party as well. No pain no gain!

 

[whatever]

Can you vonfirm if they were actually lithium iron phosphate?
Did you take voltage of fully charged pack or what is max voltage of charger written it?
If know fully charged voltage you can divide by number of cells in series and get fully charged voltage of a cell, I had a company sold me cobalt oxide type after ordering iron phosphate type, it was a long time ago though.
Also what was the max amps you were running at for 6 miles?

 

[Hyena]

I have to pay the "educational entry fee"

Heh I've paid a fortune in educational entry fees. My parts bin is rather full but I'm proudly still KFF free

 

[Lyen]

Can you vonfirm if they were actually lithium iron phosphate?
Did you take voltage of fully charged pack or what is max voltage of charger written it?
If know fully charged voltage you can divide by number of cells in series and get fully charged voltage of a cell, I had a company sold me cobalt oxide type after ordering iron phosphate type, it was a long time ago though.
Also what was the max amps you were running at for 6 miles?

Yes, I have confirmed it uses the LifePO4 18650 cells. The fully charged voltage was around 55v. Each individual cell is at 3.2v so they are really the LifePO4. The max amps was between 33-36amp.

 

[ejonesss]

looks like maybe the chinese are starting to use lipo or first generation of lithium ion ( like the laptop and cell phones used) and call it lifepo4 to scam users out of money.

 

[wineboyrider]

F##%%$#%# I hope my Pings don't explode on me.

 

[Lyen]

The LifePO4 18650 cells do not explose, they just heat up the duck tapes and burn. :?

 

[whatever]

if each cell is approx 1.1ahr? and your drawing 33 to 36amps continuously, that would equate to about 30c rate??
30c is a heck of a current draw. What would be your ahr rating of the cells in parallel, can work out what C rate you were drawing. I know some companies wont give any warranty if using over 2C, might just be the C rate was a bit much for the cells,
temperature of cells at different c rates seems to vary hugely from one maker to another.

 

[Lyen]

if each cell is approx 1.1ahr? and your drawing 33 to 36amps continuously, that would equate to about 30c rate??
30c is a heck of a current draw. What would be your ahr rating of the cells in parallel, can work out what C rate you were drawing. I know some companies wont give any warranty if using over 2C, might just be the C rate was a bit much for the cells,
temperature of cells at different c rates seems to vary hugely from one maker to another.

The cells are configured in parallel & series. So higher discharge can be sustained.