Featuring 3 MPPT inputs supporting up to 5 strings, the FlexBOSS21 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 integrate 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 FlexBOSS21 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

• 16,000W Output Power – High-capacity split-phase power for residential and commercial systems
• 21,000W PV Input Capacity – Maximizes solar production for large systems
• 3 MPPT Inputs (Up to 5 Strings) – Optimized solar harvesting and flexible design
• Split-Phase 120/240V Output – Powers both standard and heavy-duty loads
• 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 high-performance hybrid inverter built for scalability, flexibility, and advanced energy control in modern energy systems.