The EG4 FlexBOSS21 is a hybrid solar inverter built for homeowners and installers who want a scalable backup power system with large PV input capacity. It pairs solar charging, battery storage, and grid backup in one unit designed for split-phase residential service.
The FlexBOSS21 is a hybrid solar inverter architecture, meaning it integrates PV charging, battery storage, and AC output for backup power in a single chassis. Architecture classification (off-grid only vs. grid-tie hybrid with sell-back) beyond "hybrid" is [NEEDS VERIFICATION], as is any specific UL 1741 / IEEE 1547 listing citation — these are not present in the supplied data. Note: If you would like to review the manufacturer Product Specifications, Warranty, Brochure, etc., for this system, please refer to the "Resources (System Manuals and Warranty)" Tab above on this page.
Critical Power & Interconnection Requirements
- AC Output: Split-Phase configuration (exact voltage, e.g. 120/240V, not specified in source data — [NEEDS VERIFICATION])
- Continuous AC Output: 16kW
- PV Input Capacity: 21kW (maximum)
- MPPT Channels: 4 independent trackers (MPPT voltage window not specified — [NEEDS VERIFICATION])
- DC Battery Voltage: [NEEDS VERIFICATION] — not stated in source data
- Surge/Peak AC Output: [NEEDS VERIFICATION] — not stated in source data; do not assume it equals continuous rating
- Does NOT have confirmed grid sell-back capability based on available data — treat as backup/hybrid-use only until verified
- UL 1741 / IEEE 1547 listing status: NOT confirmed in source data — do not represent as utility-interconnection-approved without verification
Key Benefits
- 4 independent MPPT channels for flexible string design across multiple roof planes or arrays
- 21kW PV input capacity supports large residential or small commercial solar arrays
- 16kW continuous AC output for split-phase service
- Remote Wi-Fi monitoring for system status tracking
- Scalable design intended to grow with additional battery or inverter capacity (scaling limits not specified — [NEEDS VERIFICATION])
| Spec | Value | Unit |
|---|---|---|
| Continuous AC Output | 16 | kW |
| PV Input Capacity (Max) | 21 | kW |
| AC Output Configuration | Split-Phase | — |
| MPPT Channels | 4 | count |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
- Designed for split-phase AC output applications.
- Compatible battery chemistry: [NEEDS VERIFICATION] — not stated in source data. Do not assume LiFePO4 or lead-acid compatibility without confirming against manufacturer documentation.
- Closed-loop communication support: [NEEDS VERIFICATION] — no brand-specific closed-loop comms data provided.
- Parallel/stacking limits: [NEEDS VERIFICATION] — not stated in source data.
- NOT confirmed for grid sell-back — treat as backup/self-consumption use only pending manufacturer verification.
- NOT confirmed as UL 1741 listed — do not represent to a utility as pre-approved for interconnection without verifying documentation.
- Wi-Fi monitoring module inclusion: remote Wi-Fi monitoring is referenced in the title; confirm whether the Wi-Fi dongle ships standard or as an accessory — [NEEDS VERIFICATION].
| Listing/Code | Applicability |
|---|---|
| UL 1741 | [NEEDS VERIFICATION] |
| IEEE 1547 | [NEEDS VERIFICATION] |
| NEC Article 690 / 705 | Applicable to PV/interconnected source installation practice; verify local AHJ requirements |
| NEMA Enclosure Rating | [NEEDS VERIFICATION] |
FAQ
Can this inverter sell power back to the grid?
[NEEDS VERIFICATION] — grid sell-back capability is not specified in the available product data.
What battery voltage is required?
[NEEDS VERIFICATION] — DC battery voltage is not specified in the available product data.
Can I parallel multiple units together?
[NEEDS VERIFICATION] — stacking/parallel capability is not specified in the available product data.
Is this UL 1741 listed for utility interconnection?
[NEEDS VERIFICATION] — UL listing information is not specified in the available product data.
Warranty & Registration
Manufacturer warranty terms are not included in the provided data. Please refer to the "Resources (System Manuals and Warranty)" Tab above on this page for the manufacturer's warranty document and registration process before purchase.
