[Integration] EG4 Web Monitor Home Assistant Integration
I’m excited to share the EG4 Web Monitor Home Assistant Integration - a comprehensive custom component that brings full monitoring and control of EG4 solar systems directly into Home Assistant!
What This Integration Does
This integration connects to the EG4 Monitor web API to provide real-time monitoring and control of your entire EG4 solar ecosystem, including inverters, batteries, and GridBOSS devices.
Complete Device Support
- Standard Inverters: FlexBOSS21, FlexBOSS18, 18KPV, 12KPV, XP series
- GridBOSS Devices: Full microgrid interconnection monitoring with L1/L2 phase tracking
- Individual Battery Monitoring: Per-battery sensors with detailed cell-level diagnostics
- Multi-Station Architecture: Support for multiple solar installations per account
Comprehensive Sensor Coverage
Inverter Monitoring (~50+ sensors per device):
- Power: AC/DC power, PV generation, battery charging/discharging
- Electrical: Voltages, currents, frequency with precision scaling
- Energy: Daily/lifetime generation, consumption, grid import/export
- Environmental: Internal temperature, radiator temperatures
- Status: System status, firmware version, diagnostic information
Individual Battery Sensors (~15 sensors per battery):
- Core metrics: Voltage, current, State of Charge (SoC), State of Health (SoH)
- Cell management: Max/min cell voltages and temperatures
- Cell Voltage Delta: Calculated sensor showing imbalance between cells
- Lifecycle: Cycle count, remaining/full capacity, firmware version
GridBOSS Advanced Features (~80+ sensors):
- Grid interconnection monitoring (L1/L2 phases)
- UPS and backup load management
- 4 Smart Load Ports: Configurable as “Unused”, “Smart Load”, or “AC Couple”
- AC coupling and solar integration tracking
- Generator monitoring and control integration
Key Features
Multi-Inverter & GridBOSS Support
Unlike other integrations, this supports complex installations:
- Multiple inverters in parallel groups
- GridBOSS microgrid interconnect devices
- Cross-inverter parameter synchronization
- Hierarchical device organization
Individual Battery Devices
Each battery gets its own Home Assistant device with full monitoring:
# Example battery sensors
sensor.battery_44300e0585_01_state_of_charge
sensor.battery_44300e0585_01_cell_voltage_delta # 🔋 Great for monitoring cell balance!
sensor.battery_44300e0585_01_cycle_count
Smart Entity Management
- Automatic Scaling: Voltages, frequencies, and energy values properly scaled
- Zero Filtering: Unused sensors filtered out, but essential ones preserved
- Device Hierarchy: Clean organization following Station → Parallel Groups → Inverters → Batteries
Sample Automation: Battery Cell Balancing
The integration includes a powerful automation example that automatically manages battery top balancing:
How It Works:
- Monitors all battery cell voltage delta sensors continuously
- Detects when ANY battery has a delta > 0.05V for 24+ hours
- Balances by setting SOC limit to 101% for top balancing
- Recovers automatically after 48 hours, returning to 80% normal limit
# Simplified automation structure
- id: eg4_battery_cell_balancing
alias: "EG4 Battery Cell Balancing"
trigger:
# Start balancing: Cell delta > 0.05V for 24h
- id: "start_balancing"
platform: numeric_state
entity_id:
- sensor.battery_*_cell_voltage_delta
above: 0.05
for: hours: 24
# End balancing: SOC limit 101% for 48h
- id: "end_balancing"
platform: numeric_state
entity_id: number.*_system_charge_soc_limit
above: 100
for: hours: 48
action:
- choose:
# Set SOC to 101% when imbalance detected
- conditions:
- condition: trigger
id: "start_balancing"
sequence:
- service: number.set_value
target:
entity_id: number.flexboss21_44300e0585_system_charge_soc_limit
data:
value: 101
# Return SOC to 80% after balancing complete
- conditions:
- condition: trigger
id: "end_balancing"
sequence:
- service: number.set_value
target:
entity_id: number.flexboss21_44300e0585_system_charge_soc_limit
data:
value: 80
Automation Benefits:
Fully Automatic: No manual intervention required- Self-Contained: No helper entities needed - uses trigger IDs
- Safe: Built-in conditions prevent conflicts, manual override supported
- Customizable: Adjustable thresholds, timing, and SOC limits
Installation
HACS (Recommended)
- Add custom repository:
https://github.com/joyfulhouse/eg4_web_monitor - Install “EG4 Web Monitor”
- Restart Home Assistant
Configuration
- Go to Settings → Devices & Services → Add Integration
- Search for “EG4 Web Monitor”
- Enter your EG4 Monitor credentials
- Select station (if multiple)
- Devices auto-discovered!
Production Ready
This integration has been thoroughly tested and optimized:
- 9.93/10 Pylint Score - Production-quality code
- Comprehensive Error Handling - Graceful API failures
- Smart Session Management - 2-hour sessions with auto-reauthentication
- Concurrent API Calls - Efficient parallel data fetching
- Real-time Updates - 30-second refresh intervals
Perfect For
- Multi-inverter installations with parallel groups
- GridBOSS users needing advanced grid management
- Battery enthusiasts who want cell-level monitoring
- Automation lovers seeking advanced battery management
- Anyone wanting comprehensive EG4 system integration
Documentation & Support
- GitHub: GitHub - joyfulhouse/eg4_web_monitor: EG4 Inverter Home Assistant Integration - Monitor FlexBOSS, 18kPV, GridBOSS, and XP series devices via the EG4 web monitor API.
- Full Documentation: Comprehensive installation, configuration, and troubleshooting guides
- Sample Automations: Battery balancing and more examples included
- Community Support: GitHub issues and this forum
Credits
This integration builds upon the excellent pioneering work by @twistedroutes and their eg4_inverter_ha project.
Disclaimer
This is an unofficial integration not affiliated with EG4 Electronics. The battery balancing automation modifies inverter settings - use at your own risk and ensure compatibility with your battery system.
Ready to supercharge your EG4 monitoring? Try it out and let me know how it works for your setup! 
Questions, issues, or success stories welcome below!
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