As everyone knows, automobiles have become an essential means of transportation for people. 

In order to achieve the national dual carbon goals, the automotive industry's trend toward intelligence and electrification is unstoppable. 

With the popularity of electric vehicles, people are paying more attention to the safety information of battery packs. 

"Do you know how to improve the reliability and safety of battery pack quality?" 

In this special edition of Senasic’s Cutting-edge Technology, we will introduce the BPS Battery Pack Pressure Monitoring Sensor Chip

Senasic's BPS-SNP805 has come into being. By issuing early warning messages in advance, it helps prevent the loss of life and property caused by battery pack fires, providing strong safety protection for drivers and passengers.

SNP805 is a pressure sensing monitoring chip developed by SENASIC specifically for battery pack thermal runaway management applications. The chip integrates pressure sensing MEMS, front-end amplification and processing circuits, high-precision ADC, signal processing, interface transmission circuits, as well as temperature sensors, pressure sensors, and power supply voltage monitoring units.

Application scanarios

On the journey towards achieving high range and high energy density, there are still many safety hazards associated with the power batteries of new energy vehicles. The battery pack is installed on the chassis of the vehicle. Incidents such as compression, collision, water ingress, battery pack puncture, circuit aging, overcharging, over-discharging, overheating, etc., can trigger thermal runaway of the battery pack, leading to fires or even explosions.

Thermal Runaway Analysis

Mechanical Abuse

Under external forces, lithium battery cells or battery packs deform, causing relative displacement in different parts. For example: compression, puncture, collision, etc.

Electrical Abuse

After overcharging or overdischarging, the anode of the battery decomposes, releasing gas causing overpressure. Air reacts chemically with active substances, leading to heating.

Thermal Abuse

Localized overheating is a typical form of thermal abuse that occurs within a battery pack. Thermal abuse often develops from mechanical and electrical abuse, ultimately triggering thermal runaway.

During thermal runaway, various chemical reactions occur inside the battery pack, leading to abnormal pressure and temperature increases. Once it occurs, it cannot be stopped. The key to managing thermal runaway lies in detection and early warning. The SNP805 series products are air pressure measurement sensors capable of monitoring pressure changes in battery packs in real-time. When pressure changes exceed the normal range, they issue early warnings in advance.

System diagram

Application diagram

Core advantages

Characteristic

• Supply voltage: 3.3V Typ.

• Temperature range: -40°C~125°C

• Pressure range: 40kPa~260kPa

• Pressure accuracy: ±1.2kPa@25°C (Absolute pressure)

• Typical current in monitor mode: <30μA

For more product information and requirements for complementary development tools, please contact SENASIC technical support at info@senasic.com.

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