Imagine: at a critical moment, your electric vehicle battery management system (BMS) suddenly issues an “abnormal current” alarm, while you lose power without warning. The battery current sensor is like the “current eye” of a car. Once there is a problem, it not only affects the range but may also pose safety hazards. Only by understanding its “temperament” and “deviation” can we extinguish the fire of malfunction in the first time and ensure worry free driving.
1、 Introduction to Electric Vehicle Battery Current Sensor
The current sensor is responsible for real-time monitoring of the charging and discharging current of the battery pack, and is the core component of BMS for accurately estimating the remaining charge (SOC) and state of health (SOH). Common types include Hall sensors and shunt sensors, each with its own advantages and disadvantages – Hall sensors have strong anti-interference ability but slightly lower accuracy, while shunt sensors have high accuracy but require good heat dissipation.
2、 Common fault problems and solutions
Corresponding measures for fault phenomena
Signal drift, jitter • Check and stabilize power supply and grounding
- Add software and hardware filtering
- Investigate and stay away from sources of interference
- Re calibrate the sensor
Zero offset • Perform zero calibration procedure
If the deviation persists, replace the sensor in a timely manner
No output or constant output • Measure the integrity of power and signal lines - Use alternative sensors to troubleshoot circuit faults
- Replace module for testing
Communication interruption • Check CAN/LIN and other bus connections
Proofreading communication protocols and baud rates
Replace the communication interface module
Large temperature drift • Using high-precision sensors with temperature compensation function
Optimize installation location to avoid being close to heat sources
Response lag • Choose sensors with higher response frequency
Adjust system filtering and sampling parameters
3、 ELAPLUS Solution for Common Electric Vehicle Sensors
Adhesive/installation shell
Structural adhesive is an ideal choice for bonding the shell to the substrate, which can evenly distribute the load and reduce the weight of the sensor. Epoxy resin, acrylic or polyurethane based adhesives are all good choices.
Recommended products: SIPC 1859 - High adhesion to different substrates (PC, ABS, FR4, etc.)
- Low temperature curing
- High tensile strength and shear strength
- Not sagging
- Low displacement
Encapsulant
Although the standard production cycle for bonding and packaging requires time and has design limitations, Low Voltage Molding (LPM) uses thermoplastic materials with very low viscosity to encapsulate and package the most sensitive circuit board components, providing a protective layer against dirt, dust, moisture, and heat, and in some cases up to IP68.
Recommended products: PUR 1680 - Single component
- No need to mix materials.
- Reworkable
-30-120 second cycle time: saves time and improves productivity - Does not contain volatile organic compounds (VOCs)
Tag: Current Sensor Encapsulation
