04.9 EV battery fire suppression

How do emergency responders suppress a traction battery fire?

In researching global incidents & discussions with international fire agencies & battery experts, best practice suppression was the use of water.

At an EV fire, large volumes of water, sustained over an extended period, is the best way to suppress flames & cool the traction battery

As the transition to electric vehicles accelerates, new products are coming onto the market, some of which we look at here.

What are the challenges of suppression?

Unlike an internal combustion engine vehicle, on which flames are relatively easy to size up & suppress, an EV traction battery fire has main challenge; thermal runaway occurs within a battery cell, which is located within a battery module & pack.

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Traction battery

We previously looked at how a traction battery is constructed, & how it is positioned along the floor pan of an electric vehicle. If a battery cell goes into thermal runaway, this positioning means it's difficult to direct a stream of water directly onto the traction battery to cool it.

Suppression methods - best practice

As with all emerging industries, a range of private sector products are entering the market to form part of the solution for EV traction battery fire suppression. 

 

In addition to large amounts of water being applied for an extended period, these are some other methods being used or undergoing further testing.

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Currently used by some international fire agencies

If possible, let traction battery completely burn out.

Jack up one side for better access to underside traction battery

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Drop entire vehicle into a container of water; leave & transport.^

Has had limited use &/or is being tested

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Large thermal fire blanket over vehicle to remove oxygen

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Container with slide-in platform that seals & douses flames*

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EA500 encapsulating agent. Currently on sale via Aust suppliers.

^ Not recommended by Tesla.
* Suppressant unknown due to commercial sensitivity.