Ebike battery causes explosion in apartment block

[percymon]

Posted on pedelcs forum earlier, this is a google translate transcript from the German newspaper report. Little in the way of specific detail, and nothing to say the battery hadn’t previously been dropped or put on a faulty or incorrect charger etc etc etc..

Practical eBikes are very popular and are particularly popular with older people. A retired couple from Lengerich in the Steinfurt district had also bought the practical bicycles with an electric auxiliary motor - and should now regret this step bitterly. According to a media report, an eBike battery stored in the apartment exploded on November 6, 2020 - and blew up the couple's home. As the two 76-year-olds reported, they had been sitting in front of the TV in the living room that evening when they heard a thud around 7.45 p.m. The man looked for the cause of the noise and discovered the smoking battery in the dining room.

Battery blows up apartment - total loss!
With his presence of mind, he put the apparently defective battery in the bathtub and left the apartment with his wife. Only a few moments later the battery exploded - with devastating consequences. The detonation was so violent that some windows and doors were blown out and furniture was shattered. Together with a 29-year-old neighbor, the couple managed to get out of the house just in time. According to the police, there were no seriously injured people, but the apartment is completely destroyed and uninhabitable - the damage is likely to amount to 200,000 euros. The couple suffered slight smoke inhalation and are currently living with their daughter. The cause of the exploding battery remains unclear. It is particularly worrying that the device was not even connected to the electricity at the time of the fire and the subsequent explosion

 

[tomjasz]

Creating a safe charging station should include an ammo can.

 

[BarryS]

So he put it in the tub but didn't fill the tub with water or throw a towel over it ? putting it in the tub is probably not the brightest thing. Definately if the tub was enclosed with a curtain or doors . Just enough to cut down air : Then Again This is from which Media ? Do we know the Media is telling us the True Story ? The Cause is it over heated : No facts to go on so who knows . Maybe it was set by a register . A New house or one with older steam pipes ??/

 

[percymon]

The battery was not on charge at the time, just being stored in the house. Whether he was smart to move it a bathroom or should have taken outside is open for debate, no-one knows the full details of his mobility, time to take outside etc. He was lucky it didn’t fail while carrying it.

batteries fail, we all know that - Hyundai car recalls, Tesla fires etc etc sometimes they fail from misuse, sometimes from damage, sometimes poor manufacture.

we constantly tell people to keep batteries indoors in colder weather, do we consider all the risks in doing so ?

the article is here.. https://www.computerbild.de/artikel...-eBike-Akku-Zerstoerung-Wohnung-29246419.html

 

[percymon]

Creating a safe charging station should include an ammo can.

Agreed - And where is that in your user manual ?

sure isn’t in my Giant manual or my wife’s Kalkhoff manual , wonder if any manual does give such guidance?


In the RC world it was quite common practice with li-po batteries to use ammo cases and/or li-po charging sacks when charging and storming batteries.

 

[BarryS]

Agreed - And where is that in your user manual ?

sure isn’t in my Giant manual or my wife’s Kalkhoff manual , wonder if any manual does give such guidance?


In the RC world it was quite common practice with li-po batteries to use ammo cases and/or li-po charging sacks when charging and storming

Yes you're right . With such little to even go by I shouldn't have added my 2 cents because that's all it was worth with nothing to go on . My Apologies

 

[Ebiker01]

Creating a safe charging station should include an ammo can.

I'm looking to buy 1 asap...Can you recommend something durable for 2x 605 wh packs ? Too many choices on amazon.
Thank you.

 

[6zfshdb]

An ammo can may contain a fire but not an explosion of the magnitude described. I suspect there was water in the tub which may have been a contributing factor.

 

[percymon]

Yes you're right . With such little to even go by I shouldn't have added my 2 cents because that's all it was worth with nothing to go on . My Apologies

Nothing wrong with what you posted, it’s sound advice - pity the manufacturers don’t elaborate on safe charging and storage locations/ risk mitigation

 

[Deleted member 4210]

So he put it in the tub but didn't fill the tub with water or throw a towel over it ? putting it in the tub is probably not the brightest thing. Definately if the tub was enclosed with a curtain or doors . Just enough to cut down air : Then Again This is from which Media ? Do we know the Media is telling us the True Story ? The Cause is it over heated : No facts to go on so who knows . Maybe it was set by a register . A New house or one with older steam pipes ??/

Omg no, you don't ever want to put water on it, when it's smoldering, and certainly not into a tub of it.

 

[Deleted member 4210]

Agreed - And where is that in your user manual ?

sure isn’t in my Giant manual or my wife’s Kalkhoff manual , wonder if any manual does give such guidance?


In the RC world it was quite common practice with li-po batteries to use ammo cases and/or li-po charging sacks when charging and storming batteries.

lipo batteries are becoming rarer in most cases with Ebikes. Lipos have different issues.

And Ammo cans aren't going to do much for you. Unless you can deprive the battery of oxygen, which is going to be near impossible to do with a power cord running into it. Ammo cans are designed to protect the ammo by the way, not protect you. Ammo does not have the propensity to explode unprovoked. Your lithium battery can. What likely happened with that german guys battery by the little amount described is thermal runaway. The risk of this occurring is greater with non brand name battery cells in poorly designed packs, which usually come on the cheaper and on line sold ebikes. It's unfortunate to see stories like this that have too few details disclosed, such as brand of battery or its pack design. It could have very easily been home made, or even one of those you see in blue plastic wrapping on Alibaba, or not even have a BMS. People buy this sort of stuff on line, trying to DIY an ebike conversion, (to 'save money') who have no business doing so, and tons of on line sellers will be happy to accommodate them.

Also, There is a huge difference between properly designed ebike battery packs with Samsung cells etc, versus RC packs. You just cannot compare them at all. First of all you have far fewer cells in most RC packs, so yeah ammo cans might offer some modest protection in that situation where you have a lot fewer cells and of course less overall energy. You have maybe a handful of cells in RC packs, versus 65 , give or take in ebike packs. I've worked with RC packs from when I was a kid, as they migrated thru the various chemistries. Eventually to lithium.

You actually needed to take more precautions with those RC packs (once they got into using lithium) despite them having a lot fewer cells and less overall energy capacity in a pack. Less risk (than many RC packs) when buying a quality ebike priced over at least $1300, as long as the ebike has name brand cells like Samsung or Panasonic or LG. Sanyo cells are great too, and very high quality, but rare to find on Ebikes from an OEM, as they are pricey. The bms and it's quality also plays a very important role in the safety of a pack. (we see far too specs on the BMS in the cell packs, from any ebike OEM, IMHO.) So it's not just about the cells. It's in part why I cringe when I see ebike brands priced below $1000 touting their use of 'brand name' cells, but yet there is nothing at all disclosed about how they are packed, connected, and what BMS is being used. They are cutting tons of corners to sell an ebike at or below $1000, and so the battery being the most expensive component on a ebike priced at that level or below,is the most suspicious target for cost and corner cutting.

Even better, If you can find a battery pack that uses fused links, or an ebike brand that offers those types of packs as standard, fused links between cells increases safety and helps to mitigate thermal runaway. Smart Motion ebikes (here in the US a few years back, but pulled out after Lectric Cycles disbanded), provided those type of packs. It costs more, and you can purchase them on your own, and if you are really concerned, those packs may be worth the extra investment.

P.S. if you are going to buy an ebike used, first thing I would do is go out and buy a brand new battery pack with good brand name cells, and with the charger designed for it. Do so from reputable supplier, or better yet, buy one from the ebike OEM who's brand label is on the ebike. You have no idea how the prior battery was handled, whether it was dropped, left in the cold, how it was charged etc. We are talking safety here and so whatever you would spend extra to get a new battery is worth every penny.

PPS. instead of an ammo can, if you are really worried about an explosion, consider a heavy duty safe. It's fire rating isn't quite as critical as how it's built and it's strength. The heavier and thicker the walls the better. Some will come with holes in the bottom that allow you to bolt it to the floor. Don't bolt it down, but use one of the holes for your charge cord. Leave the charger outside of the safe itself. I know a guy who puts his cell pack out in the middle of the back yard when he charges it, runs an extension cord out to it, and the pack is placed inside his brick and cinder block outdoor fireplace. I suppose thats for peace of mind.

 

[Dallant]

An ammo can may contain a fire but not an explosion of the magnitude described. I suspect there was water in the tub which may have been a contributing factor.

I have heard that removing any gasket on the door of the ammo can could help to reduce explosive pressure. The whole idea is to contain fire effects/spread for an amount of time providing an opportunity to potentially get it out of your house. Wrapping the battery in fire blanket fiberglass sheets before putting it in the ammo can could help also.

 

[Ebiker01]

fire blanket fiberglass sheets

aerogel material also has amazing fireproofing features.

 

[tomjasz]

I'm looking to buy 1 asap...Can you recommend something durable for 2x 605 wh packs ? Too many choices on amazon.
Thank you.

Mine came from Midway.
Lid gasket removed for charging use.

 

[rdowns]

I have heard that removing any gasket on the door of the ammo can could help to reduce explosive pressure. The whole idea is to contain fire effects/spread for an amount of time providing an opportunity to potentially get it out of your house. Wrapping the battery in fire blanket fiberglass sheets before putting it in the ammo can could help also.

like your new avatar

 

[tomjasz]

And Ammo cans aren't going to do much for you.

Other than confine the burning pack in a case for removal. As to the cords, simply unplug.

 

[Dallant]

Not an ammo can but...
I finally put a simple and, hopefully, fire resistant plan in action for in-house storage this winter. I know there are some who think it foolish but having been a volunteer photographer of a Fire Department for three years, I take fire very seriously. This is not to prevent a fire but it is to hopefully contain a battery fire long enough to get us or it out of the house safely.
First, I got a metal tool box just long enough to fit both PowerTube batteries. Then, I got a fiberglass mat fire blanket and wrapped one battery in it and placed it in the bottom of the box. Then, I put the other battery in the box wrapped in the other half of the fire blanket. The tool box is very close to a smoke detector and will be on a tile floor. We also have another fire blanket close to it.
Obviously no way to test this but the local Fire Marshal acquaintance thought it sounded like a good plan. Hopefully we never have a fire to find out!