Battery Box
Description
The goal of this project is to create an all-in-one battery box capable of charging from multiple sources: mains power, external 12V power supply unit (PSU), and solar panels. The system incorporates an internal 40Ah battery and includes circuit breakers on every load connection to ensure safety and protection.
This project aligns with an overall philosophy of creating a modular, potentially transportable station, rather than creating a single all-in-one portable shack, as has been quite popular over the years. The modular approach allows for flexibility, easier maintenance, and the ability to adapt the system to different operational needs.
Overview
Components List
| Component | Description | External Reference |
|---|---|---|
| WestMountain Radio EPIC PWRGate | 12V uninterruptible power system with high-performance charger and solar panel input. Supplies up to 40A continuously. | EPIC PWRGate Product Page |
| Victron Smart Shunt 300A | High-precision battery monitor with Bluetooth Low Energy (BLE) connectivity for real-time monitoring of voltage, current, and state of charge. Connected to Raspberry Pi Zero W2 via BLE. | SmartShunt 300A Announcement |
| Solice 40Ah LiFePO4 Battery | Lightweight, long-lasting lithium iron phosphate battery with built-in BMS protection system. More than 2,000 charge/discharge cycles. | Solice LiFePO4 Battery (Reference) |
| Raspberry Pi Zero W2 | Compact single-board computer with WiFi and Bluetooth, used for system control and management via web interface. Communicates with Victron Smart Shunt via BLE. | Raspberry Pi Zero 2 W |
| 12V USB C Power Converter | DC-DC voltage converter that steps down 12V or 24V battery voltage to 5V USB-C output. Provides up to 5A (25W) for powering USB devices from the battery box system. Features wide input voltage range and efficient power conversion for reliable USB device charging and operation. | View on Amazon |
| 230V-12V AC/DC converter | AC to DC power supply converter that transforms 230V mains voltage to 12V DC output for charging the battery box system. Enables charging from standard European mains power outlets, providing a reliable power source when solar or external 12V supplies are unavailable. | View on Amazon |
| ADUM3160 USB Isolator | USB 2.0 full-speed isolator providing 2.5 kV isolation between EPIC PWRGate and Raspberry Pi Zero W2. Supports data rates up to 12 Mbps. | ADUM3160 Datasheet |
| Fuse Box / Circuit Breaker Panel | Distribution panel with circuit breakers for protecting individual load connections. Provides overcurrent protection for each output circuit in the battery box system. | Fuse Box on Amazon |
| Pelican 1430 Protector Case | Durable, watertight, and dustproof top-loading case with high-impact polypropylene construction. Features automatic pressure equalization valve, secure double-throw latches, and customizable Pick N Pluck™ foam protection. Interior dimensions: 34.4 x 14.6 x 29.7 cm. | Pelican 1430 Product Page |
User interface
The Battery Box Status webpage is a real-time monitoring dashboard that displays the operational status and electrical parameters of the battery box system. It provides a web-based interface for monitoring battery health, power sources (solar panels, power supply), and load consumption.
Data Sources: The webpage aggregates data from two hardware devices. The Victron SmartShunt communicates via Bluetooth Low Energy and provides battery voltage, current, power, State of Charge (SOC), and capacity information. The EPIC PWRGate communicates via USB serial connection (through the Raspberry Pi Zero W2) and provides power supply voltage/current, solar panel voltage/current, load current, and system temperature.
The interface features a visual battery gauge with color-coded charge levels, a status table showing electrical parameters for battery, power supply, solar, and load, and a detailed data modal accessible by clicking the battery percentage. Data updates in real-time via WebSocket communication.
Open Issues
Failing Connectivity Between Raspberry Pi and EPIC PWRGate
The read-out software for the EPIC PWRGate works perfectly fine on the development machine. However, once installed on the Raspberry Pi, the system loses network connectivity as soon as the USB connection is established between the Raspberry Pi and the EPIC PWRGate.
Root Cause Analysis: Initial analysis pointed to USB ground loops as the likely explanation. Issues were observed when connecting the Raspberry Pi to the EPIC PWRGate USB interface simultaneously with a USB power supply, which raised concerns regarding ground potential differences and electrical interference.
Attempted Solution: To address these issues, an ADUM3160-based USB isolator was implemented between the EPIC PWRGate and the Raspberry Pi Zero W2. This isolator provides 2.5 kV isolation and supports USB 2.0 full-speed data rates up to 12 Mbps, designed to break ground loops and protect equipment from potential damage caused by ground potential differences.
Current Status: Unfortunately, the suggested solution failed to produce satisfactory results. The network connectivity issue persists when the USB connection is established on the Raspberry Pi, despite the USB isolator being in place.
This is currently an open issue. Any suggestions on how to proceed would be welcomed.
Note: The Raspberry Pi Zero W2 and Victron Smart Shunt 300A communicate over Bluetooth Low Energy (BLE), enabling wireless monitoring and control without the need for physical connections. This communication path remains unaffected by the USB connectivity issue.