The spread of electric cars and more generally of lithium batteries in the most varied sectors, it has prompted the main companies producing equipment for firefighters to create special systems for extinguishing a lithium battery in Thermal Runaway. Turning off an electric car in the event of a fire involving the lithium battery may require a lot of water, up to 30,000 liters according to Tesla to cool the battery. This article is part of a special on the extinction of lithium batteries that we wanted to create to talk about this problem from another angle, telling you the different solutions currently on the market. We will detail two innovative systems that offer different application methods to help firefighters extinguish and control an electric vehicle fire. Here’s how they work and the differences between AVL Stingray and Rosenbauer BEST.

AVL STINGRAY AND ROSENBAUER BEST: WHAT THE DIFFERENCES

As we explored in our mega survey on the risks of electric cars in the event of a fire, one of the main difficulties faced by firefighters is to be able to cool a battery in Thermal Runaway, given its position, under the passenger compartment. Two Austrian solutions, similar in purpose but very different in their application:

• BESTacronym of Battery extinguishing system technologycarried out by Rosenbauera company specializing in the production of vehicles and special equipment for firefighters;
• stingray oneaccomplished AVLa company specializing in the development, simulation and testing of mobility technologies in the automotive industry and other sectors.

The main difference between the two systems is that Rosenbauer BEST works from outside the car and the battery. During AVL Stingray One, is operated from inside the cockpit. Both systems provide for the introduction of water directly into the battery. These features lead to advantages and disadvantages that we have analyzed, which we will talk about in the following paragraphs after seeing the two systems up close, even on video.

ROSENBAUER BEST: HOW A LITHIUM BATTERY BURN

The system Rosenbauer Battery Extinguishing System Technology consists of two main elements:

• A drill nozzle which, in primary use, is positioned by firefighters under the car, directly at the hottest point of the battery;
• A Control unitwhich is connected to fire hydrant or fire truck with hoses.

THE advantage principal for which it was developed BEST – according to the company – is to allow firefighters to be fast, with a time of about 2 minutes by carafter which it can be activated by a safety distance (8 meters) to avoid the heat and toxic gases that are released during the combustion of a lithium battery. A nozzle enters the battery case pushed with a force of several tons and through a hole in it water is fed directly into the battery. As it shows the video below the optimal positioning is between the road and the floor of the car, when the vehicle is resting on its wheels. However, the company specifies that it is possible to use the system by placing it against the bodywork, from inside the passenger compartment and from the luggage compartment, or from above in the case of vehicles on the side. or knocked down.

AVL STINGRAY ONE: HOW IT WORKS ON A HOT LITHIUM BATTERY

The system stingray one was developed based on expertise of the company in high-voltage batteries for vehicles. Security, efficiency and speed are the pillars on which the operation of Stingray is based. AVL. It is composed :

• Asingle unit with penetrating nozzle integrated which must be connected to the fire pump or a common fire hydrant via a hose.

When connected to the water supply source e placed in the cockpit, the system can also be operated and controlled remotely. The patented nozzle system penetrates the floor of the car and the battery box by injecting water directly onto the modules to be cooled. Although it seems to work best inside the car, the company claims that it can also be used outside the car, such as permanently placing it in a garage.

BETTER VS STRINGRAY: PROS AND CONS OF LITHIUM BATTERY FIRE

The systems manufactured by Rosenbauer and by AVL seem to have benefits commmon that meet the needs of check, cool and turn off the lithium battery of an electric car in thermal runaway faster compared to the use of conventional pipes. Also amount of water used is less because introduced directly into the battery, compared to that necessary to cool the cells from the outside. However, we believe that in both cases there are intervention situations that are more complex than others. For example:

• Rosenbauer The best can be pushed under the car through a dielectric sheet, even if the fire started to develop with high temperatures.
• AVL Stingray Oneas the company video shows, must be anchored inside the cockpit, a condition that makes it more suitable for the phases preceding the thermal escalation of the battery. Otherwise, firefighters could still find themselves operating in an area with a high risk of explosion and production of toxic gases.
• Best Rosenbauer it would seem more effective when used under vehicles that are not knocked over or too tilted.

• AVL Stingray Oneanchored inside the passenger compartment, between the floor and the roof, it must be able to function regardless of the location of the car, straight, sideways or upside down. Nevertheless the glass of cars with panoramic roofs could be broken crystal and be less effective on some models.