Battery pack sensor applications for new energy vehicles

New energy vehicles all have the same characteristic - they all have battery packs. The internal structure of the battery pack is similar in that they all have a battery, a box for the battery, a high-voltage wiring harness, a low-voltage wiring harness, a high-voltage isolation system, a battery management system, a thermal management system, and so on.

Introduction to the New Energy Lithium PACK line

New energy lithium battery PACK generally refers to packaging, encapsulation and assembly. As a key step in the production, design and application of new energy lithium power battery systems, PACK is the core link between upstream cell production and downstream vehicle application.

What needs to be considered when designing the battery pack?

1. The space requirements of the whole vehicle, the space between the parts of the whole vehicle chassis and the space where the battery pack is located;

2、The pure electric range requirements of the whole vehicle, i.e. how many kilowatts of electricity this battery pack needs to be designed for;

3、Choose the battery, including the shape of the cells, square case, soft pack or cylindrical, and the capacity of each cell.

4、Understand the operating voltage range of other electrical equipment in the vehicle, which will determine how many cells are used in the pack and how many strings are used, and the BMS will have requirements for the series and parallel connection of the cells when monitoring the cells in the battery pack.

Temperature sensing required for battery packs

1. Thermal management system

Vehicle thermal management system from the perspective of system integration and the whole vehicle, coordinate the whole vehicle heat and environmental heat, using heat dissipation, heating, insulation and other means, so that different parts can work at the right temperature, to protect the functional safety and service life of the vehicle and improve the performance of all aspects of the vehicle.

Traditional automotive thermal management systems mainly include engine and transmission cooling and air conditioning system thermal management; new energy vehicle thermal management includes engine electronic control system thermal management, battery system thermal management and passenger compartment air conditioning thermal management, etc.

2. Cooling System

The cooling system must maintain the battery at its normal operating temperature and includes radiator plates, radiator hoses, heat conducting rubber and exhaust valves.

3.BMS

The BMS is the brain of the battery pack and consists of a CMU (Cell Monitor Unit), which is responsible for measuring the voltage, current and temperature of the battery and transmitting it to the BMU, and a BMU (Battery Management Unit), which is responsible for evaluating the data transmitted by the CMU and, if the data is abnormal, protecting the battery by issuing a request to reduce the current or cut off the charge/discharge path to prevent the battery from exceeding the permitted conditions of use. If the data is abnormal, the battery is protected by issuing a request to reduce the current or cut off the charge/discharge path to prevent the battery from exceeding the permitted conditions of use, as well as managing the power and temperature of the battery.

Monitoring the voltage, current and temperature of the battery cells and other information, through the current state of the battery cells, to predict the next charge and discharge power of the battery cells has been and state, so as to better use the battery cells, but also control the disconnection of the BDU. The BMS monitors the insulation status of the battery pack and also monitors the temperature information inside the battery pack.

A quality battery pack company must develop and design bespoke battery pack BMS solutions, thermal management, space dimensions, structural strength, etc. based on the individual needs of the car manufacturer's customers for different models.