Battery fires?

[dodgeman]

So I did a search on battery fires and found several threads. One thing I haven’t found is what is causing fires? Are the batteries catching fire? Do they get hot and catch nearby things on fire? If you have a brand name bike, say Trek with the Bosch motor is that safer?

 

[Dave Rocks]

Also can you buy a Ebike battery fire extinguisher?

 

[rich c]

Bosch battery packs are UL rated, so yes they are safer. Yes the batteries are catching fire. The cells explode and shoot off like bottle rockets. It's very difficult to put out the chemical fire and once it gets hot enough, everything catches fire.

 

[Gordon71]

So I did a search on battery fires and found several threads. One thing I haven’t found is what is causing fires? Are the batteries catching fire? Do they get hot and catch nearby things on fire? If you have a brand name bike, say Trek with the Bosch motor is that safer?

Why would a particular brand of motor make whatever battery that's powering it safer?

 

[dodgeman]

I don’t know if someone like Bosch makes the battery or specs the battery or if Trek does. I’m asking, I don’t know the answer.

 

[Gordon71]

I don’t know if someone like Bosch makes the battery or specs the battery or if Trek does. I’m asking, I don’t know the answer.

I really know nothing about Trek EBikes so I went over to their site. As far as I can tell the don't sell batteries at all or I couldn't find any for sale at their site which is weird. How can they sell EBikes and not sell replacement batteries?

 

[Stefan Mikes]

I really know nothing about Trek EBikes so I went over to their site. As far as I can tell the don't sell batteries at all or I couldn't find any for sale at their site which is weird. How can they sell EBikes and not sell replacement batteries?

Spare batteries are available for Bosch E-Bikes (such as Trek), Specialized, and Giant for sure. In case of Trek, the battery is a Bosch E-Bike product, and as such, it does not need to be advertised on the Trek website.
For your information, I own as many as three Specialized U1-600 batteries, and as many as three Specialized SL Range Extenders. A friend of mine bought a Bosch spare battery for his Merida e-bike last Autumn.

I'm sure other big brands sell spare batteries, too.

 

[Gordon71]

Spare batteries are available for Bosch E-Bikes (such as Trek), Specialized, and Giant for sure. In case of Trek, the battery is a Bosch E-Bike product, and as such, it does not need to be advertised on the Trek website.
For your information, I own as many as three Specialized U1-600 batteries, and as many as three Specialized SL Range Extenders. A friend of mine bought a Bosch spare battery for his Merida e-bike last Autumn.

I'm sure other big brands sell spare batteries, too.

OK I was just surprised that a Ebike dealer wouldn't have replacement batteries as part of their inventory.

 

[Stefan Mikes]

OK I was just surprised that a Ebike dealer wouldn't have replacement batteries as part of their inventory.

There's a general lack of spare batteries in the market because of known reasons... Not that they would not be offered if available. Besides, I believe it is rather difficult to order a spare battery from a big brand online. (I might be wrong but I cannot see, say, spare Specialized batteries available on the European websites but I could have got them ordered by the LBS).

 

[rich c]

Bosch batteries are sold at REI. https://www.rei.com/c/electric-bike-accessories

 

[retiredNH]

I really know nothing about Trek EBikes so I went over to their site. As far as I can tell the don't sell batteries at all or I couldn't find any for sale at their site which is weird. How can they sell EBikes and not sell replacement batteries?

It's because they're Bosch made and branded batteries. In Trek's case, and probably others who use the Bosch systems, you get the batteries from Bosch.
In answer to whether battery brand matters, it's like anything else we buy, except that with batteries, the stakes are higher - you can buy at a range of price points, with different quality (in some cases). Some things are better made, but at a price.
Manufacturers develop specifications for products they make and sell, which can influence performance, safety and price. Name brand ebike component manufacturers like Bosch and Specialized are known for reliable, sturdy components, at a high price point. No-name manufacturers typically focus on price, at the sacrifice of everything else - longevity, durability, safety etc.

 

[AHicks]

So I did a search on battery fires and found several threads. One thing I haven’t found is what is causing fires? Are the batteries catching fire? Do they get hot and catch nearby things on fire? If you have a brand name bike, say Trek with the Bosch motor is that safer?

1. Charging, especially when using a junk or incorrect charger or charging when the pack is hot. My bet is this is what's causing the majority. For instance- most chargers are set up to shut off at a particular voltage. If there is a dead or bad cell, maybe multiple bad cells, (or maybe frozen, ?) within the pack, the voltage will never get up to the point where the charger shuts itself off. This can result in a battery pack that just keeps getting hotter and hotter with predictable results.

2. A dead short within the battery pack can cause a runaway (over heating) issue as well.

3. Poor construction can allow cells to rub together, against wiring, against anything, and eventually the battery cell case may wear through allowing it to vent - causing a fire. Older batteries that have been allowed to sort of rattle around within a container or case are especially well known for this.

I'm sure there are other reasons, especially when talking home made, but that should give you an idea....

 

[Edrummer]

Battery explodes while camping.

 

[how]

My partner has become worried about all of the reported e bike battery fires. Perhaps too much time has been spent on u tube videos of these occurrences.

so because most of the solutions to these fire issues have simply failed in any independent tests and
I also like to charge my batteries off the bikes & inside my home (for theft security and away from freezing temps).....

so....
I only use stock-brand name manufactured batteries.
I don't charge batteries beside each other because one thermal runaway will set off an adjacent batteries.
I use a luna charger that can limit the charging input to 1 amp and to either 80/90 or 100%.
I charge my battery in a welders toolbox that's been fully lined with a 1 inch layer of fortified & re-enforced concrete.
That tool box is internally vented through the wall to the outside with an insulated 3/4 black iron pipe.
The area immediately around this tool box is protected by a fire proof hardi board.
I have a furnace turbine fan run air handler beside it that is set up to automatically direct vent any fumes to the outside that can escape from this fire vault.

probably over kill but I guess that's what most insurance turns out to be.

 

[tomjasz]

I use a luna charger

A charger is known for its short life and common failures.

That tool box is internally vented through the wall to the outside with an insulated 3/4 black iron pipe.

WELL DONE!

over kill

No, well thought out and well done!

I charge my battery in a welders toolbox that's been fully lined with a 1 inch layer of fortified & re-enforced concrete.

Any enclosure should be vented. If not it's a bomb.

 

[how]

@ tomjasz
If I do ever get a thermal runaway situation, all that explosive potential is going to make that 3/4" black vent pipe to the outside sing like a flame thrower.
Because it is difficult to know how many cells may fire off at one time, I am unsure when charging a battery whether to latch the top of the tool box to have it be a fully compressive fire vault or just leave it unlatched to have the 10lb. of cement in the hinged top lid act as a momentary backup explosives damper?

 

[tomjasz]

I'd love to see your solution tested. Sadly I have a lot of packs that could be used for testing but no one locally seems to give sh!t.