The Power Keeper Accessory (Master) is the central control unit for Sungrow ST series battery systems, acting as the Battery Management Unit (BMU) for the entire stack. Designed to manage and coordinate multiple battery modules, this controller ensures safe, efficient, and optimised operation across the full energy storage system.

As the “brain” of the battery stack, the PK Accessory (Master) monitors system performance, manages charge and discharge behaviour, and provides critical protection functions. It enables seamless communication between battery modules and the wider system, ensuring reliable operation in residential and commercial energy storage applications.

Key Features

• Central BMU controller – manages and monitors up to 250kWh (with slave units)
• System coordination – ensures balanced operation across all connected battery modules
• Advanced safety management – protects against overvoltage, overcurrent, and temperature events
• Optimised performance – intelligent control of charge and discharge cycles
• Seamless system integration – designed specifically for Sungrow ST series battery systems
• Real-time monitoring & communication – enables system diagnostics and operational visibility
• Supports scalable systems – essential component for multi-module battery configurations

Technical Specifications