Paris suspends electric bus fleet after fires.

[Andrew LB]

 

[KITROBASKIN]

No explanation if it was charging at the time.

 

[turbodog]

Given that no injuries and no people exited...

 

[PhotonWrangler]

Wow. It's amazing how quickly and violently it went into full thermal runaway.

 

[xxo]

some details -

Paris Suspends 149 Bolloré Electric Buses After Two Fires

Manufacturer Bolloré Group said that its Bluebus unit was actively cooperating with the RATP and relevant authorities to determine the causes of the fires.

insideevs.com

 

[thermal guy]

Why are the batteries on the roof?

 

[Hooked on Fenix]

Usually don't see something like that except in the movies, if the bus drops below 55 mph. This looks like the sequel, No Speed.

 

[idleprocess]

From the Inside EVs article:

Bolloré's 12-meter (39-foot) long electric buses can transport up to 109 passengers and offers an estimated driving range of up to 320 kilometers (199 miles) from Lithium Metal Polymer (LMP) battery packs totaling 441 kWh of stored energy.

LiPo packs for transportation strike me as a bit novel. My image of LiPo is high power density to weight at the expense of energy density and the physical robustness of conventional li-ion.

I gather that RC events pretty routinely use cinder block + sandbag containment cells for recharging them, such is their tendency to vent energetically, however that might also be due to aggressive charging regimens.

 

[Olumin]

Why are the batteries on the roof?

Thats what Id like to know too.

 

[bykfixer]

Welp, I was going to buy an electric car.
Not now, no sir, uh uh. Not gonna happen.

 

[turbodog]

Thats what Id like to know too.

If they ignite, flames travel upwards. On the roof... passengers can exit underneath the flames, being only broiled, like a whopper. Underneath the belly... flames engulf the bus, leaving a nice crust on the passengers/kebabs.

Probably better protected from vehicular impacts also.

 

[idleprocess]

If they ignite, flames travel upwards. On the roof... passengers can exit underneath the flames, being only broiled, like a whopper. Underneath the belly... flames engulf the bus, leaving a nice crust on the passengers/kebabs.

Probably better protected from vehicular impacts also.

Can't help but wonder if the choice of LiPo chemistry necessitated this design choice.

 

[PhotonWrangler]

While it's probably much safer for passengers, it could set some trees on fire. It's amazing that it apparently didn't cause something else to catch fire.

 

[xxo]

Thats what Id like to know too.

Buses need to ride low to the ground to better accommodate people with disabilities - if they put the batteries underneath they would be vulnerable to road damage.

 

[thermal guy]

Guess it's more appropriate to say when they ignite. but still all that molten aluminum and crap will rain down on them I would think.

 

[turbodog]

Guess it's more appropriate to say when they ignite. but still all that molten aluminum and crap will rain down on them I would think.

If I were designing it, I would certainly see a tray capable of withstanding a reaction underneath the pack. That won't stop the spray ejected by the reaction itself, but it's a start.

 

[Hooked on Fenix]

If I were designing it, I'd locate the battery pack at the very back of the bus with a bimetallic type of passive ejection system like a circuit breaker or a thermoelectric fan for a wood burning stove. If the battery pack heated up too much and was going to explode, it would be pushed behind and away from the bus. It would suck for tailgaters, but the passengers would survive if the bus was moving.

 

[jtr1962]

If I were designing it, I'd just use LiFePO4 cells and avoid the vast majority of problems in the first place. Sure, fires can still start if the cells are shorted, but at least they won't go into thermal runaway.

 

[Bimmerboy]

On the roof... passengers can exit underneath the flames, being only broiled, like a whopper.

And the children like Whopper Juniors! 🔥 🔥