E-Bike fires

[Packard]

There have been so many fires started by the batteries of e-bikes that apartment buildings in New York City are not allowing them to be stored indoors. 

Why are they catching fires?

Since the e-bikes use lithium ion batteries which are the culprits in the fires, what are the risks with the lithium ion batteries in our tools?
https://www.cnn.com/2023/03/09/tech/lithium-ion-battery-fires/index.html

CNN
—
Lithium-ion batteries, found in many popular consumer products, are under scrutiny again following a massive fire this week in New York City thought to be caused by the battery that powered an electric scooter.

 

[John T.]

From what I understand the risk is with cheap, non-UL ebikes/batteries. I have a Specialized (Brose) which is UL, which aren't supposed to be (as) dangerous. I still don't charge it at night while asleep unless I really need to.

This rule sucks for lower income short term but hopefully pushes the ebike industry to safer products.

I wouldn't be worried about power tool batteries, especially name brands like Dewalt and Festool. They should have sufficient protection to prevent runaway thermal events.

 

[Packard]

You would think Ford would use quality batteries for their EV Lightning pickup truck, but it is subject to a recall because of fires.
https://insideevs.com/news/663559/ford-f150-lightning-fire-recall-capture-police-video/

The Dearborn Police Department, near Detroit, Michigan, recently published previously unreleased footage of the Ford F-150 Lightning fire that reportedly sparked the recent recall. Thanks to Michigan's Freedom of Information Act, the footage is now live for everyone to see.

CNBC Television hosted the video on its YouTube channel and shared that it reveals smoke rising up from three electric pickup trucks that are parked closely together. The fire took place at a Ford holding lot in Dearborn, not far from where the automaker's world headquarters is situated.

 

[woodferret]

Charging causes heat.  Heat can cause the breakdown of the separators and polymers.  If the separator breaks down, you have a short and a very large energy exchange causing more heat.  But more likely, the failure mode is impurities in the polymer that have a lower heat tolerance.  They dissociate into gas and form pressure on the battery casing.  This is where the bloated batteries come from.  Casing is generally rated pretty good for external punctures, etc but if the polymer is of a lower grade than spec's there can be quite a lot of pressure and heat build up.  If the gas escapes and is mixed with oxygen and heat, you get fires.

As far as tools go, be wary of knockoff batteries.  I'd recommend not changing overnight even with official batteries, but especially with the airstream and duo chargers. 

 

[John T.]

Chevy had a huge recall of Bolt EV's, made by LG, which isn't exactly a Chinese knock off brand. If I recall correctly it was a manufacturing defect. Parking garages were banning Bolts, some still do. There was a temporary recall where they simply limited the state of charge to 80 or 90%.

The number of actual fires was pretty low, but those are big batteries to extinguish.

It sounded like these ebikes were catching fire pretty frequently. Like the hoverboards in the late 2010's.

Ironically, Ford has an active recall for ICE Explorers catching fire.
https://www.cbsnews.com/news/ford-suv-recall-engine-fire-expedition-navigator/

 

[Packard]

Apple recently recommended against overnight charging.  But I think that was a warning about cheap chargers rather than against the batteries themselves.

I had a Ford Lightning pickup truck the year they came out with an auxiliary tank.  It held close to 40 gallons of high octane gas.  I remember worrying about driving with that much gas in the truck.

I had some serious issues with the truck, but fires were not among them.

 

[kmickey]

Since the e-bikes use lithium ion batteries which are the culprits in the fires, what are the risks with the lithium ion batteries in our tools?
https://www.cnn.com/2023/03/09/tech/lithium-ion-battery-fires/index.html

CNN
—
Lithium-ion batteries, found in many popular consumer products, are under scrutiny again following a massive fire this week in New York City thought to be caused by the battery that powered an electric scooter.
[/quote]

I work in a bike shop, and the capacity of a bike battery compared to a festool battery is significantly higher. (500-750 Wh)The battery in our bikes weighs more than a tracksaw with batteries installed.
It’s company policy to not charge (newly built or unsold) bikes overnight, but the company has never had a problem with a battery fire.

We do maintenance on all brands, and let’s just say, there are huge differences in quality between ours and the no-name brands.