DEVELOPMENT OF A WIRELESS CELL BASED BATTERY MANAGEMENT MODULE

Abstract

This report describes the design and development of a wireless cell based battery management module. The module should be able to accurately measure the battery voltage, current and temperature and then transmit this information wirelessly to a receiver. The system should have a low power consumption both when the monitored battery is used and when it is not. At least 40 systems should be able to communicate simultaneously. The design does current measurements through a shunt resistor, voltage measurements using a voltage divider and an Analog to Digital Converter(ADC) and temperature measuring using the microcontrollers own sensor. Wireless transmission is achieved by a SPIRIT1 radio chip combined with an antenna and is broadcasted on the 868 MHz radio band using a custom designed protocol. The system can perform all the desired measurements, with generally high accuracy. An issue with the antenna prevents long range communication and multiple units, but tests indicate that the wireless communication concept is feasible for at least 40 units. The power consumed is not a significant part of the total battery capacity when in use, but drains the battery relatively quickly when not in use.