Low Power Design of a Wireless Sensor Node to Monitor Electric Car Batteries

Electric vehicles require monitoring of car batteries. Wireless sensing is desirable to eliminate connecting wires, resulting in low installation and maintenance cost. This paper presents a low-power wireless sensor node and an interface circuit to monitor the battery pack of an electric vehicle. To save power, the proposed sensor node adopts the wake-up/sleep mode and reduces the transmission time through compaction of the data to transmit. The wireless sensor node is prototyped with a Texas Instruments low power microcontroller CC1310, where CC1310 embeds a variant of Zigbee radio and a 12-bit analog-to-digital converter. The prototype monitors the voltage and temperature of nine battery cells and the battery pack current. The measured power dissipation of the prototype is, on average, 1.2 mW. Considering the power dissipation of the microcontroller is 22 mw during transmission, the proposed method reduces the power substantially.