Tesla Fire!!

[chl]

Yes they are rare.

But personally, I'd like to have a zero chance of an EV fire when the EV is doing what EV's normally/are designed to do, that is, charge.

Charging an EV should be as fool-proof or more than pumping gas into a tank.

Since there are no gas lines to leak like in an ICE, and the charging is under the control of computers once it starts, you would think it would be 100% fool proof and any fire has to be because of a manufacturing defect or damage to some component.

Could be the EVSE, the cables, the plugs/connectors, or the Li batteries.

Li batteries need good management software to keep them healthy and with balanced cells.
Good temperature control as well.

DC Fast charging can be especially stressful to Li batteries and the wires and connections that carry the large currents.

There is a lot of chemistry and physics to consider. Temperature is critical to avoid thermal runaway. Letting the EV battery "rest" to cool down before recharging is always recommended, but out on the road on a long trip, do people follow that recommendations or trust the technology to handle it, and not try to charge a battery if it is too hot to do safely?

They also recommend not leaving the EV battery at 100% charge for extended periods of time which can result in battery damage.

Just as they always warn about pouring gas into a hot lawn mower, for example, because of the risk of fire, people frequently ignore the recommendations.

While EV battery fires are rare, I wonder about ALL fires involving Li batteries - they are sound in cell phones, laptops, etc. as well?

Just looking at fires on planes there are quite a few incidents in the 10 years from 2012 to 2022:

"Over 152,000 incidents of battery fires have been reported between January 2012 and January 2022, according to the Federal Aviation Administration. The risk of a lithium-ion battery fire is about 1 in 10 million, based on data from the Consumer Product Safety Commission."

https://www.google.com/url?sa=t&sou...4QFnoECBUQAw&usg=AOvVaw00eFZRyII9FXGfeyA8SYuN

It seems that EV fires from news reports most frequently happen either while charging or after an accident that damages the battery.

Even ICE vehicles can have "battery" fires - faulty wiring or switches is generally the culprit.

Like any consumer product we put our trust in the manufacturers to design them to be safe when used according to instructions.

I think maybe manufacturers need to make the "recommendations" for proper use inherent, that is, provide lock-outs/fail-safe mechanisms, so you, for example, can't charge the EV when it would be unsafe due to temperature, so you can't leave a battery at 100% for a long period of time, and so forth.

A pipe dream.

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[chl]

What I am asking for is better safeguards for the main things that cause battery fires:

1) better quality control in manufacturing - think about the Lightnings that caught fire at the plant lot during/after charging
2) fail safe controls over charging levels and temperature so that when things are potentially dangerous the software prevents charging
3) more headroom in battery size and software control so batteries never get charged to 100%
4) better EVSE design and maintenance so things can handle the currents they are expected to
5) better battery shielding so they cannot be ruptured during an accident

I think those things are doable and would eliminate some of the EV and other Li battery installation fires. The fires in EVs although "rare" are serious when they do happen. Most happen as a result of an accident or during charging.

Technology can't eliminate all accidents yet, but fires because of charging seem to me to lend themselves to fixes because they are under software control.

Until the battery technology improves and EV batteries that have the potential to catch fire are replaced, I think some improvements could be made for safety.

Another way to eliminate some of the risks would be battery swapping stations which would eliminate the need for the owner/driver to DC fast charge. Swapping can even be faster than fast charging anyway. (see: https://ample.com/ for an example)

As an electrical engineer and patent attorney, I rarely believe that "it can't be done" or "it's impossible" especially when it comes to safety.

Most of the time designs and software can be improved, and/or new technology invented.

PS: remember the statistics that rate EV fires vs ICE fires are measured as fires per billion miles traveled or per 100,000 vehicle sales. So for the latter, the rate is 61 times lower for EV's than ICE vehicles. Rarer, but still...
(see: https://www.forbes.com/sites/neilwi...uilty-of-excess-short-term-fire-risk-charges/)

I wonder how as the EV fleet ages, if the numbers will change significantly?

"A study by the Swedish Contingencies Agency for 2022 found that all fuel types produced 68 fires per 100,000 vehicles compared to 3.8 fires per 100,000 vehicles for EVs. The number of EV fires should increase as more battery packs age and remain on the road."
(see: https://insideevs.com/features/720764/ev-electric-car-fire-risk-safety-burn/)

As the batteries age, the chemical reactions take their toll, it is just physics and chemistry, and inevitable entropy.

 

[chl]

This article gives a good explanation of the main causes of EV fires I think.
Basically they are:
1) internal battery flaws,
2) external charging circuitry flaws
3) charging/discharging cycles and
4) high temperatures.

Of course there is overlap among them. That is why I think quality control and design improvements could eliminate most of these issues.

https://evreporter.com/main-causes-of-ev-fires/

 

[AAT]

It's recommended to let batteries rest before charging whenever possible. Why is it okay to DC fast charge on a road trip? Is road tripping bad for EV batteries?

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