Battery packs are at the core of all cordless equipment, and they all include battery management systems (BMS) to interface with chargers and power tools to maintain proper operating conditions. The BMS monitors each battery cell and total battery pack voltage and operating current to ensure safe and reliable operation. It communicates with chargers and power tools, and can alert the system or user of its status and readiness for use. The BMS consists of a microcontroller, battery monitoring and control circuit, power supply, power control switches, communication circuits, and LEDs to manage battery charge and to indicate its status. The BMS microcontroller (MCU) controls all battery pack functions and samples battery cell voltages, system current, and pack temperature using battery monitoring and control circuits. The MCU enables or disables the corresponding power control switches to the tool or charger as requested by the power tool or charger. The system indicates the state of charge through an LED array or display and a button to control the indicator.
Key Challenges
New generation battery packs need a long lifetime to allow more charge and discharge cycles. Battery management systems must execute accurate monitoring of single cells to ensure the right balance among them.
High-end batteries may feature BLE connectivity and security features.
Our products and Solutions
ST offers a broad range of 32-bit STM32 microcontrollers including ultra-low power MCUs that are ideal for the BMS applications. Additionally, ST provides an extensive portfolio of power MOSFETs, discrete products, and sensors to complete the BMS solution offering.
The ST NFC and BLE product portfolios enable secure and reliable wireless connection between the battery pack, the charger, and the tool.
