Electric mobility and thermal runaway
Electric mobility has fundamentally changed the way we travel. At the same time, electric vehicles introduce new challenges, particularly with regard to the safety of lithium-ion batteries. Thermal runaway describes the uncontrolled overheating of a battery cell and can lead to fire or explosion. The resulting overpressure may cause severe damage to equipment and create hazardous conditions for both people and the environment.
This article highlights the different approaches to detecting such hazards and explains the crucial role sensors play in prevention.
Recognizing the danger: Two different approaches
To minimise damage in the event of thermal runaway, electric vehicles must be equipped with a range of sensors. Equally important, however, is the early detection of emerging faults and the ability to issue warning signals to vehicle occupants before thermal runaway occurs.
A new range of Honeywell sensors for enhanced safety in EV batteries and energy storage systems offers an optimal combination of performance and reliability.
Two different approaches to detecting and responding to this risk are outlined below:
Battery safety sensors for fire safety
Battery safety sensors detect early signs of thermal runaway and communicate with the vehicle system via CAN communication. Programmable warning thresholds allow the sensors to be adapted to the specific configuration of the battery system.
BAS Series – Battery Safety Aerosol Sensors
Functional principle
Thermal runaway causes the release of gases from battery cells. During this degassing process, aerosols and smoke gases are emitted.
The BAS Series consists of aerosol sensors that use the principle of light scattering to detect and report thermal runaway events in lithium-ion battery packs.
BPS Series – Battery Safety Pressure Sensors
Functional principle
A change in pressure caused by the swelling of a lithium-ion battery enclosure is an early indicator of thermal runaway.
Honeywell’s BPS Series monitors the absolute pressure within lithium-ion battery packs. If the measured pressure or the rate of pressure increase exceeds a predefined threshold, a warning signal is transmitted to the battery management system.
Current sensors for the BMS (battery management system)
The CSHV and CSNV Series consists of current sensors that use Hall-effect sensing combined with patented Honeywell technology to deliver an optimal balance of performance and reliability for current measurement applications.
Honeywell current sensors provide highly accurate measurements for critical functions such as battery management systems, including power management, deep-discharge protection, overcharge protection and state-of-charge monitoring.
Typical areas of application include:
Battery Management System (BMS):
In electric vehicles, the BMS ensures that the battery operates within safe limits and protects it against overcharging, overheating and deep discharge.
Battery Disconnect Unit (BDU):
The BDU provides a critical safety function by interrupting the power supply in the event of incidents such as a collision, helping to protect vehicle occupants and electrical components.
Power Distribution Unit (PDU):
The PDU acts as the central power distribution system within the battery architecture, supplying all critical loads in the electric vehicle.
As a result, current sensors play a key role in electric vehicles by monitoring and controlling current flow across multiple subsystems. They enable efficient energy management, support optimal battery performance and allow potential issues to be detected at an early stage, ensuring safe and reliable vehicle operation.
The role of sensors in prevention and other areas of application
Sensors are essential in electric vehicles to ensure the safety of passengers and other road users. Their role is to detect potential hazards at an early stage and enable timely responses. Sensors can be used to identify collision risks and support automatic braking functions to help prevent accidents. In addition, they continuously monitor vehicle conditions to detect potential faults early and initiate corrective measures. Overall, sensor technology makes a significant contribution to the safety and reliability of electric vehicles.
Beyond their use in electric vehicles, lithium-ion battery packs are also deployed in a wide range of other applications, including:
Energy storage: Lithium-ion battery systems are used to store renewable energy from sources such as solar and wind power, allowing excess energy to be stored and accessed when required.
Emergency power supply: Lithium-ion battery packs serve as backup power sources in the event of grid failures. They are commonly used in uninterruptible power supply (UPS) systems to maintain operation of critical infrastructure such as servers or medical equipment.
Honeywell EV sensors
As one of the market leaders in safety-related sensor technology, Honeywell sets industry benchmarks by combining innovative technologies with high-quality materials. The result is sensor solutions that meet the highest standards while delivering precise measurements and reliable performance.
As an authorised distributor, we have full access to Honeywell’s extensive portfolio of high-quality sensor products. Our dedicated team is always available to answer your questions and support you in selecting the right sensor solution for your specific requirements.