A Wireless Temperature Monitoring Method for Battery Pack

With the growing popularity of new energy applications, such as electric vehicles, the safety of battery packs is increasingly prioritized. This paper presents a Radio-frequency identification (RFID) based wireless high-temperature monitoring method for battery pack. This method proposes an RFID tag design that includes a radiator introducing a reed switch and an interdigital capacitive structure. Controlled by the magnet, the reed switch has two states: on and off, which can change the working state of the RFID tag. When magnetic materials are embedded in the battery pack, their magnetism can control the reed switch of the RFID tag to the off mode, which is placed on the surface of the battery pack. As the battery temperature increases, the magnetism of the magnetic material gradually diminishes until it reaches the Curie temperature. When the internal battery reaches a certain temperature, the reed switch’s state changes, and the RFID tag enters the working mode to transmit information. Meanwhile, the capacitive structure is also attached to the surface of the battery pack, affecting the working frequency and phase of the RFID tag radiator as the temperature changes.