https://www.dropbox.com/scl/fi/4i5nwecmg8vh8pcw8i2vd/BeamOneV2-BMS-6S_Rev-1.3.drawio?rlkey=82empoctk4p71r1koaytd9um1&st=3zdy6lfo&dl=0

Revision History

Version	Date	Author	Changes
1.0	May 19, 2025	Per-Arne Andersen	Initial draft of functional requirements. Defined core functionality, power rail architecture, and state transitions.
1.1	May 20, 2025	Per-Arne Andersen	Some clearifications

Functional Requirements

Introduction

The Battery Management System (BMS) provides comprehensive power management for a portable gaming device, serving as the power regulation and protection interface between a 5-6 cell LiPo battery pack and the gaming system. The system will utilize two separate board designs: one supporting 3-6 cell configurations and another for 1-4 cells if there is a substantial cost difference between the designs.

The system implements a hierarchical power architecture with the following voltage rails:

V_RAW_0: Primary always-on rail delivering power from battery or USB-C to downstream components
3V3_0: Always-on rail powering the BMS microcontroller, maintained during deep sleep for essential functions and wake-up detection
3V3_1: BMS-controlled rail powering the gaming system's microcontroller, enabling computer system to interact with BMS through I2C communication
5V_0 and 5V_1 and V_RAW_1: Dual-control rails manageable by both BMS and gaming system via I2C, with BMS retaining protective override authority
V_DYNAMIC_1: Controlled by the BMS. Similarly to the 5v_1.

The BMS serves two essential functions: battery management and power distribution. It ensures safe battery operation through comprehensive monitoring and protection while providing controlled power sequencing to the gaming system. Though the gaming system can request power state changes via I2C for specific rails, the BMS maintains ultimate control for safety.

To optimize power efficiency, the BMS features a deep sleep mode while maintaining the 3V3_0 rail for critical monitoring and wake-up detection. This enables response to user input and USB-C connections while minimizing battery consumption.

The system operates seamlessly on battery power or during USB-C charging, incorporating comprehensive safety features including over-charge/discharge protection, cell balancing, thermal monitoring, and emergency shutdown capabilities.

The BMS utilizes the AVR32DBx microcontroller family. https://www.digikey.no/no/products/detail/microchip-technology/AVR32DB28T-E-SS/13415138

<aside> 🚨

Key Component Specifications:

V_RAW_1 rail requires XT30 connector for power output.
USB-C implementation requires 6-pin connector. JST or equivalent?
We need 5A on the 5v_1 line. Something like TPS6293x for the 3v3 DC ?
We need 2A on the 3v_1/2 line
V_RAW_1 should not have any buck-boost. Its straight from battery, but controllable.
V_DYNAMIC_1 should provide programmable output voltage. Suggested IC: TPS55287 </aside>

https://www.dropbox.com/scl/fi/iz5bg7dafhrj35urewm6y/BeamOneV2-BMS-6S_Rev-1.1.drawio?rlkey=y5j6f79b5z2ec8pciz9edljvl&st=bit8hkuq&dl=0