Product Summary:
The EG4 FlexBOSS18 Hybrid Inverter is a high-capacity, next-generation solution designed for residential and commercial energy systems. With up to 18,000W PV input and 13,000W split-phase (120/240V) output, it delivers powerful, flexible performance for both on-grid and off-grid energy systems.
Featuring dual MPPT inputs supporting multiple strings, the FlexBOSS18 maximizes solar production while efficiently managing energy from solar, battery, grid, and generator sources. With 90A grid feed-through, it supports high-demand loads and seamless system integration.
Designed to pair with the EG4 GridBOSS MID gateway, the system enables advanced energy control including smart load management, AC coupling, and generator support, while simplifying installation and reducing system costs. Built-in protections such as rapid shutdown, ground fault, and arc fault protection ensure safe and code-compliant operation.
With Wi-Fi connectivity, remote monitoring, and mobile alerts, the FlexBOSS18 provides full system visibility and control, making it a reliable, scalable solution for modern energy independence.
Ships From: Texas, USA
Warranty: 10 Years
Support: Lifetime USA-Based Tech Support
Compatibility
UL 9540 Certified + Closed-Loop Communication (Grid-Tied + Off Grid):
- BigBattery ETHOS
- EG4 Batteries
Power Compatibility:
- Works with 48V battery systems
- Supports grid-tied, hybrid, and off-grid installations
- AC coupling compatible for system upgrades and retrofits
- Integrates with EG4 GridBOSS MID for advanced system control
Key Features
- 18,000W PV Input Capacity – High solar input for large residential and commercial systems
- Split-Phase 120/240V Output – Powers both standard and heavy-duty loads
- Dual MPPT Inputs – Optimizes solar production across multiple arrays
- 90A Grid Feed-Through – Supports high-demand loads and seamless grid integration
- GridBOSS Integration – Enables advanced load management, AC coupling, and generator support
- Advanced Safety Protections – Includes rapid shutdown, ground fault, and arc fault protection
- Smart Energy Management – Supports peak shaving and intelligent power distribution
- Remote Monitoring & Alerts – Real-time system tracking via Wi-Fi and mobile app
- Flexible System Design – Ideal for grid-tied, hybrid, and off-grid installations
- Installer-Friendly Design – Reduces installation time and system complexity
- Maintenance-Free Operation – No routine servicing required
A powerful, scalable hybrid inverter built for performance, flexibility, and advanced energy control in modern energy systems.
EG4 FlexBOSS18 Hybrid Solar Inverter | 18kW PV / 13kW AC | Split-Phase | 2-MPPT | Scalable | Remote Wi-Fi Monitoring
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3 Phase
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12500W (6 min) | 11000W (12 min)
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10-Year EG4 Manufacturer Warranty
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See More On YouTube
Inverter Downloads
DOWNLOADDOWNLOADDOWNLOADGO TO LINKInverter Specifications
12500W (6 min) | 11000W (12 min)
Compare Inverter
10-Year EG4 Manufacturer Warranty
Frequently Asked Questions
FlexBOSS18 or 18kPV: which is better?
The FlexBOSS18 gives 13,000W output against the 18kPV's 12,000W, with the same 18,000W PV input. It adds 90A grid feed-through, GridBOSS integration and built-in rapid shutdown, ground fault and arc fault protection. It is the newer generation and the better fit for code-driven installs.
Do I need the GridBOSS with the FlexBOSS18?
No, the inverter works on its own. The GridBOSS 200A MID is an optional add-on that enables smart load management, AC coupling and generator support while simplifying installation and reducing system cost. Add it if you want control over which circuits stay live during an outage.
Is the FlexBOSS18 UL 9540 certified with the ETHOS?
Yes. It is UL 9540 certified with closed-loop communication for both grid-tied and off-grid operation, with BigBattery ETHOS and EG4 batteries listed as compatible. UL 9540 applies to the inverter and battery as a system, so the pairing matters for permitting.
What does 90A grid feed-through mean?
It is how much grid current can pass straight through the inverter to your loads without going through the battery. A 90A feed-through supports high-demand circuits and larger service panels, which is what makes whole-home integration practical rather than limiting you to a subpanel.
What safety protections does the FlexBOSS18 include?
Rapid shutdown, ground fault protection and arc fault protection are built in, which are code requirements on most grid-tied residential solar installations. It also includes Wi-Fi connectivity, remote monitoring and mobile alerts for full system visibility.
EG4 FlexBOSS18 Hybrid Solar Inverter | 18kW PV / 13kW AC | Split-Phase | 2-MPPT | Scalable | Remote Wi-Fi Monitoring
