48V Lithium Battery Multi-Group Parallel BMS Technical Proposal

This technical proposal details a battery management system (BMS) for 48V lithium battery modules used as backup power in telecommunication equipment rooms. The system supports multiple groups of 15-16 series 50-100AH modules operating in parallel, housed in a rack-mounted structure with up to 12 modules per cabinet. Key features include monitoring voltage, current, SOC, SOH, and temperature of each cell, automatic identification of lagging or faulty cells, and a pre-charge/pre-discharge circuit to prevent circulating currents during parallel connection. The three-level architecture comprises BMU (Battery Management Unit) for individual module control, a central control module for data processing and communication with up to 10 modules, and an optional master control module for larger systems. The system ensures high reliability through redundancy: if one module fails, the system continues with reduced capacity; up to five modules can be offline while maintaining operation. It also provides a 7-inch display for status monitoring and multiple communication interfaces (CAN, RS485, Ethernet) for integration with PCS, UPS, or rectifiers. This design enhances safety, simplifies maintenance, and extends battery lifespan.