Bike battery fire

[dogman dan]

In the news, but for obvious reasons, not put up on ebike insider.

http://www.globalpost.com/article/6561040/2015/05/26/fire-ignited-bicycle-battery-burns-down-row-house-finland

 

[alexis57]

The resident had left the bicycle without charging. The battery short-circuited, heated...

short-circuited ?! the battery pack itself ? I cannot understand lol someone touched... it's compulsory.

It's not said if it's a homemade or a basic ebike.

 

[MadRhino]

Unplug battery when a bike is not in use.
Even better when the bike is built properly: Take it off and store in a safe place

That is what I keep telling to everyone, yet a friend lost his battery to a short recently.
I will show him this article, so he can have an idea about how it could have been much worse if the short circuit would have been closed to higher current.

A short can happen for so many reasons, especially when a bike does a lot of mileage in all weather conditions or worse, riding dirt and crashing once in a while. We are many here to ride the mountain trails or commuting with powerful bikes, and the problems seem to curse always the same riders. Go figure, some just can't learn until a brick falls on their head.

 

[Syonyk]

And thus continues the progress towards ebikes being banned by insurance and rental agreements...

Nobody knows or even cares if it's a homebuilt pack or something professional with a BMS. An ebike is an ebike is an ebike to most people, and they Burn Down Houses(TM).

 

[MadRhino]

And thus continues the progress towards ebikes being banned by insurance and rental agreements...

Nobody knows or even cares if it's a homebuilt pack or something professional with a BMS. An ebike is an ebike is an ebike to most people, and they Burn Down Houses(TM).

Cars are killing 1.5 million per year in accidents, and even more by health consequences, yet nobody cares. :wink:

 

[Syonyk]

Cars are killing 1.5 million per year in accidents, and even more by health consequences, yet nobody cares. :wink:

Yup. And a lot of people and a lot of very well backed interests are keeping cars more or less secure against any serious attempts to remove them.

The vast majority of people don't know what an ebike is, don't care ("It's still a bicycle, right? Why would anyone ride that unless they're too poor for a car/have too many DUIs/etc?"), and there's not much money floating around to block any legislation against them.

Which is my point. If insurance companies and rental companies decide they want to ban ebikes, nobody will be have the resources to fight it.

So try to keep your batteries from lighting on fire.

 

[granolaboy]

I wonder how differently people would perceive a story like this if it simply said "A Battery shorted and caught fire", rather than mentioning anything about the ebike.

The ebike in the story seems irrelevant. It could have been an RC car he was charging, or pretty much anything else electrical shorting out.

I mean, with this logic, why don't we just ban electricity all together? It's obviously too dangerous to leave in the hands of joe-q-public...

 

[Eclectic]

And of course gasoline powered cars never catch on fire :?

The National Fire Protection Association (NFPA) says that vehicle fires account for about 20 percent of all reported fires

http://auto.howstuffworks.com/car-driving-safety/accidents-hazardous-conditions/10-causes-of-car-fires.htm

Things like Christmas trees and electricity never cause a problem...

Electrical problems were factors in one-third (32%) of home Christmas tree structure fires.

http://www.nfpa.org/safety-information/for-consumers/holidays/christmas-tree-fires

Fires happen, that's why we have fire departments. Where do you park your vehicle full of gasoline?

But, if we are ambassadors and evangelists, then we need to be extra cautious.

 

[Syonyk]

I wonder how differently people would perceive a story like this if it simply said "A Battery shorted and caught fire", rather than mentioning anything about the ebike.

Well, that's not how they're written. If something uncommon (ecig, ebike, etc) lights on fire, especially if it's something people don't like, that's mentioned.

But, if we are ambassadors and evangelists, then we need to be extra cautious.

This is mostly my point. Some people here encourage putting together battery packs that are best described as "hazardous," and the "annual lithium battery fire/arc flash/etc" threads don't do much to dispel this perception.

At least in the US, bicycles are mostly viewed as toys, and ebikes are further into the "toy" class - most people do not consider them viable commuter vehicles, even though they are.

 

[Hillhater]

And thus continues the progress towards ebikes being banned by insurance and rental agreements....

Cars are killing 1.5 million per year in accidents, and even more by health consequences, yet nobody cares. :wink:

And a lot of people and a lot of very well backed interests are keeping cars more or less secure against any serious attempts to remove them......

They won't remove or ban cars because society as we have it today is built around the concept of personal transport, and currently there is no practical alternative to the car for individual transport.
Also insurance companies have a vested interest in maintaining there livelihood from the revenue generated by ever increasing insurance premiums...they may even take advantage of more accidents to increase premiums (revenue) proportional to risk.
The most likely outcome from exaggerated reports of Ebike fires, is the legislation of insurance requirements for them....and registration, and Liciencing !....IE - just like other forms of motorised transport !

 

[dogman dan]

The stories are always sketchy, because by the time full investigations are complete, the fire is old news months ago.

No telling whether the short they say caused the fire was internal cell shorts, pack construction shorts outside the cans or pouches, or a nicked wire somewhere on the bike. But the general point of origin on fires is pretty easy to determine, and in this case an electric bike.

Remove battery and store in a safe place always best. Next best, unplug it at least. I thought this story was particularly interesting because of the number of people affected. Apartments for example, are no place for cheap ass hobby lipo cells.

 

[Syonyk]

I'd personally argue that ebikes are no place for cheap ass hobby lipo cells, but I think that ship has sailed on ES...

 

[MadRhino]

I'd personally argue that ebikes are no place for cheap ass hobby lipo cells, but I think that ship has sailed on ES...

Well, the world is no place to burn fossil fuel...
And any combustible material has no place in the hands of idiots.

We use the batteries that can supply the power that we need, and recommend safer chemistry to those who don't need so much power. I am abusing RC lipo for years, yet never set one cell on fire. I know someone who is using LifePo4 and set them on fire, twice in a year. A conscious man can use dynamite safely, and an idiot can burn a fire station.

 

[Syonyk]

The right answer, for the vast majority of people, is a professionally built pack, with reasonably safe battery chemistries, and a high quality BMS that has per-cell high voltage and low voltage cutoff, balancing, and thermal sensors. That's very unlikely to catch on fire or need any sort of maintenance, and while more expensive, it's going to "just work" for years of daily use, and not require any fancy handling to keep it from failing or bursting into flames.

And how on earth do you get LiFePO4 to light up short of flat out abuse?

I would have far less of a problem with hobby cells if people were running a full BMS across them, but the vast majority of people aren't, and are bulk charging, which leads to inadvertent cell abuse, exceeding low and high voltage thresholds, and battery damage/fires.

 

[dnmun]

the most common short that lead to fire as reported here is a short of the positive charging lead to the battery or the BMS. in the case of chroot's fire the wires from the charger had the red positive charging lead running directly through the BMS housing and the wire shorted to the BMS so it led to the positive lead coming off of the battery for the charger to be so hot that it caught the nylon bag on fire that the battery was contained in. luckily he had the garage door open and the neighbors saw the smoke and came over to his house and then he dragged it outside onto the driveway.

 

[dogman dan]

Stuff like that will do it. It's quite possible something similar started this fire.

 

[Alan B]

Low quality BMS's cause many problems.

Simply dropping a professionally built BMS protected battery on the floor can cause major problems.

Perfect safety is quite difficult to achieve.

 

[Ykick]

Bicycles really have no history of burning until they’ve been electrified so I’m not surprised about sensational reporting opportunities these accidents provide for so called “news” publishers.

Large energy exchange(s) can erupt in flames. Short circuit, improper charging, over discharging, bad construction, poor chemical composition, harsh weather, accident damage, take your pick. Any number of things can/will converge and sometimes fires result.

With humans fear is always a prevalent theme when it comes to the unknown. Just look at constant crazy being whipped up regarding UAS (unmanned aircraft systems)?

It’s merely the beginning of an industry and as someone said “we’re stewards” so do the best we can and not become “one of those” stories demonized and promoted by click-bait reporting publications.

 

[dnmun]

but as an engineer i can see ways to reduce all those risks. put a fuse on the positive charging lead at the B+ terminal. use a BMS to protect against shorts on the output. avoid running the large conductors adjacent each other so that they cannot be shorted together if they rub on a metal part that can cut through the insulation on the cables.

none of that was followed in the case of the only lifepo4 fire we had, except he did have a BMS, and the positive charging lead ran right through the BMS so it could be shorted there.

 

[MadRhino]

And how on earth do you get LiFePO4 to light up short of flat out abuse?

Last time I whitnessed: The guy had drained low and couldn't pedal the heavy bike. He put it in the back of a taxi cab. Rubbing caused a short on the assembly of his big Headway pack, setting fire to the plastic spacers and case. Damages on the bike and taxi cab, same day fixed but costly. Luckily this happend in the presence of 2 people (taxi driver and bike rider) who could smell the fire. They got the bike out of there quickly but the fire continued until the battery taken apart.

Cause:

Idiocy: Built a bike that could not be pedaled, a battery that couldn't stand physical abuse, transported it with negligence.
Double idiocy: The same guy had set fire to his previous LifePo4 pack, less than a year ago.

My mule (Santa Cruz V 10 dirt bike) is built with 24s RC lipo and has no BMS (IMO, BMS is not a safe way to care for RC lipo).
It had many crashes since it is the bike that I ride in the worst conditions, some damages of course, never a fire. Once I watched it flip and jump like a deer down a hundred feet, hitting a few small trees before it stopped. I went down the hill, checked everything, climbed back on the bike and ride. 8)

Building your own, should be to do better than what they are selling ready made. Build it to ride fast and hitting hard, or buy a scooter.