As the core of new energy electric vehicles, on-board battery is directly related to vehicle life, mileage, vehicle economy, and safety, all of which depend on the performance of the battery management system. However, the monitoring accuracy and execution reliability of the battery management system depend on various sensors, so the research and analysis of sensor technology is particularly necessary.

The Battery Management System (BMS) monitors the voltage, current, load, temperature and other status of the vehicle battery, and can provide safety, communication, cell balance and management control for it, and provide a communication interface with the application equipment. system. The main sensors used in BMS are current sensors, temperature and humidity sensors, voltage sensors and so on.

1. Temperature sensor

Temperature is of great significance to BMS performance. In order to further improve battery utilization, prevent battery over-discharge, and increase battery life, a built-in NTC temperature sensor is used to monitor temperature.

The NTC temperature sensor is mainly made of oxide compounds of high-purity metal elements such as Mn through the combination of ceramic technology and semiconductor technology. The working principle is that these materials have fewer carriers and higher resistance. When the temperature increases, the number of carriers corresponds to increase, the resistance correspondingly decreases. It has the advantages of high resistivity, small heat capacity, fast response, excellent linear relationship between resistance and temperature, flexible, low price and long life. There are three types of commonly used: ground ring shell NTC temperature sensor, commonly known as "ground ring type"; epoxy resin encapsulated NTC temperature sensor, commonly known as "water drip head", "little black head"; thin film NTC temperature sensor.

2. Humidity sensor

A humidity sensor is a device or device that converts the amount of ambient humidity into an electrical signal that can be marked. A common humidity sensor measures relative humidity. At present, the commonly used humidity sensors for BMS of new energy electric vehicles include resistive humidity sensors and capacitive humidity sensors. The principle is to coat a layer of moisture-sensitive material film on the substrate. When the water vapor in the environment is adsorbed on the film, the resistivity and resistance value of the element will change, and the humidity can be measured.

The humidity factor is particularly difficult to capture in the battery management system of new energy electric vehicles, but it has a huge impact on the performance and life of the battery. The humidity output of the sensor is temperature compensated to obtain a linear voltage, which is input to the BMS of the new energy electric vehicle with ADC.

In the future, the monitoring data accuracy of sensor technology for new energy vehicle products will become more and more precise, and more accurate data will be required for the collection of data such as current, voltage, temperature and humidity, so as to improve users' accurate grasp of battery system operating conditions. The next step is to start from theoretical simulation and experimental research at the same time, and research and explore a new generation of high-efficiency and high-precision BMS sensors for monitoring.

Hefei Fusen Sensing Technology Co., Ltd. has a team of high-quality design and development engineers with more than 15 years of design and development experience, focusing on the research of high-precision, high-temperature-resistant, high-waterproof sensor devices, BMS temperature sensors, etc. You can call the company's service phone 0551-6910-9668 through the website to learn more about the product details. Welcome new and old customers to buy their favorite products with confidence, we will serve you wholeheartedly!