# Electric Busses in Paris



## kennybobby (Aug 10, 2012)

During April there were 2 EV busses that caught fire. The batteries are located in the roof, and one site mentioned that roof damage is suspected from contact with a bridge, but a full investigation report has not been released.







A different Make had a similar issue, this was not in Paris [Arie says its not EV even though it has that in the utube title, and it's definitely burning differently]


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## remy_martian (Feb 4, 2019)

Those buses must be a complete joy to drive when turning a corner with several tons of battery 12 feet up.

It would make sense there was a crush event, though.


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## ArieKanarie (12 mo ago)

The second video is a CNG powered bus, not electric.


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## brian_ (Feb 7, 2017)

ArieKanarie said:


> The second video is a CNG powered bus, not electric.


I have no idea about that specific bus, although it certainly looks like escaping pressurized gas burning, but it is true that both batteries and compressed natural gas fuel tanks are typically mounted of the roof of low-floor urban transit buses. They would be under the floor of a conventional bus, but there is simply no usable space under the floor in low-floor designs.

Some of the double-decker designs popular in the UK do some interesting packaging to fit everything in - even in conventional diesels that still need to pack in the engine and fuel tank - and there may be a better solution than putting the entire battery on the roof. With a low floor the wheel wells (at least the front ones) are too tall to have seats over them, so they're usually just unnecessary baggage shelves - perhaps packs there would be preferable since they are lower than the roof and better protected from overhead hazards.


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## ArieKanarie (12 mo ago)

What would happen if the battery behaves like the one in the first video while there's passengers inside?


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## remy_martian (Feb 4, 2019)

They'd get out of the bus, just as they would in any bus that scraped the ceiling going under a low bridge. 

Tesla's module and pack design spent a lot of engineering time & money on mitigating thermal runaway and buying egress time, something where jamming cells together and binding them in contact with each other with heat shrink doesn't do.


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## kennybobby (Aug 10, 2012)

It could be a bad day unless the design engineers had the experience to anticipate problems. 

For example, hopefully the Battery Management System (BMS) would sense any trending increase in cell temperatures at an earlier point in time and issue caution and warning messages to the operator, such that he would be aware of an anomalous situation with the Battery.

if the temperature continued to rise above the caution level, then the BMS should issue commands to the Electric Vehicle Control Unit to throw emergency messages to the operator and initiate shut down of the the motor and disconnection of the Battery Pack Main Contactors. i would expect that the operator has been trained to immediately pull over and stop, and instruct passenger to leave the bus and move away as far as possible.

Examples of lack of experience and design failures:
Recall that there were 2 Lithium Battery fires on Boeing 787 Dreamliners and that airplane fleet was grounded until the root cause could be determined and remediation measures were implemented. This battery pack consists of 8 cells with an internal 4-level BMS and is used as a starter battery for the turbine-driven Auxilliary Power Unit (APU) that supplies power when the main engines are off. 

The fix was to build a containment vault with a vent out to the side of the airplane, to exhaust the smoke in the event of another fire. The root cause appeared to be overcharging, but Boeing would never admit or agree to this, even though the logs from the Flight Data Recorder showed that the Battery is constantly being charged during flight. Anyone with lithium cell experience knows that you never trickle charge cells; once they are full you stop charging.

In addition several years before that the company that built the 787 on-board chargers, Securaplane, in Phoenix had a fire that destroyed their lab facility back when they were first doing actual battery charging testing. The fix was to only use a simulator of a battery for testing the chargers..? This tells me that Boeing and their subcontractor Securaplane are out of their lane--they may be engineers but lack experience and know nothing about using Lithium cells.


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## Deane (Mar 21, 2020)

It seems there have been quite a few EV bus fires. Here are a few caught on camera:
https://www.expaturm.com/german-lif...tric-buses-numerous-fire-incidents-in-germany 




Paris Suspends 149 Bolloré Electric Buses After Two Fires


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## remy_martian (Feb 4, 2019)

"Quite a few"? The anti-EV and pro-fossil fuels chimps always have a field day with such news.

Meanwhile, here's an ICE bus snapshot in time of what's *currently available* at *one* of the auctions:


































Mind you the population is smaller, but bus fires are not unheard of.


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## MarkDoronin (8 mo ago)

Definitely the best evidence!


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