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- 16kW AC output with PV, 12kW from battery
- 21kW usable PV input, 3 MPPTs
- 90A grid feed-through at 120/240V
- Up to 5 strings, 3 orientations
- Pairs with GridBOSS for AC coupling, smart loads, generator
- EMP-hardened, NEMA 4X enclosure
- 10-year limited warranty
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The FlexBOSS21 (V1.1) is EG4's flagship 48V split-phase hybrid inverter/charger. It offers the dependability of the 18kPV with more flexibility and power. It accepts 21kW of usable PV (24kW max input) on three MPPTs and delivers 16kW AC with solar or 12kW from batteries alone, enough to start a 5-ton air conditioner. It can pass through 90A of grid power. Parallel up to 16 units for as much as 256kW of continuous output with PV, and pair it with the EG4 GridBOSS MID to manage the entire energy storage system while cutting installation cost.
Highlights
- Flexible operation: off-grid, grid-supported, or exporting excess solar to the grid
- High PV voltage: up to 600VDC, which allows smaller conductor sizes
- Three MPPTs for flexible array design
- Big-load capable: starts a 5-ton AC unit
- Scalable: parallel up to 16 units (256kW continuous with PV)
- Smart connectivity: Wi-Fi remote management with mobile notifications and remote settings; closed-loop communication with compatible batteries
- Safety: rapid shutdown, ground-fault monitoring and arc-fault protection
- Listings: UL 1741 Certificate of Compliance; CEC Solar Equipment List
- GridBOSS integration for whole-home load management
Specifications
| PV input | 21kW usable / 24kW max |
| Max PV voltage | 600VDC |
| MPPTs | 3 |
| On-grid AC output | 16kW @ 240V; 13.8kW @ 208V |
| Battery-only output | 12kW (12,000VA) |
| Nominal output current | 50A (66.7A max continuous) |
| Output voltage | 120/240V, 120/208V, 240V |
| Grid passthrough | 90A |
| Battery voltage | 48V |
| Parallel | Up to 16 units |
| Dimensions | 30.4 × 22.3 × 11.2 in |
| Weight | 121 lbs (55 kg) |
| Warranty | 10-year EG4 manufacturer warranty |
The EG4 FlexBOSS LCD Screen Kit is sold separately.
| Manufacturer | EG4 Electronics |
|---|---|
| Model Number | IV-16000-HYB-AW-FX-XX |
| Rated AC Output (on-grid, PV+grid) | 16kW (66.7A) |
| Rated AC Output (battery only) | 12kW (50A) |
| Max PV Array | 21kW (STC) |
| Max DC Input Voltage | 600 VDC |
| MPPTs | 3 (120-440 VDC operating) |
| Battery | 51.2 VDC nominal (40-60 VDC), 250A max charge/discharge |
| AC Output | 120/240VAC or 120/208VAC |
| Max Pass-Through From Grid | 90A |
| CEC Efficiency | 97% |
| Enclosure | NEMA 4X |
| Operating Temp | -13 to 140°F (-25 to 60°C), derates >45°C |
| Dimensions (HxWxD) | 30.43 x 22.28 x 11.22 in (773 x 566 x 285 mm) |
| Weight | 121 lb (55 kg) |
| Certifications | UL 1741 SA/SB, PCS CRD, Rule 21, CSA, IEEE 1547, FCC Part 15 B |
| Warranty | 10 years |
Specifications are from the manufacturer and may change. Questions? Call (888) 831-0450.
EG4 10-year limited warranty
| Coverage | 10-year full parts or full product replacement from original purchase date |
|---|---|
| Registration | register within first year of purchase, or keep proof of purchase from an EG4 authorized distributor |
| Transfer | original purchaser; transferable once if unit stays at original installation site |
| Residential vs commercial | no separate terms stated |
| How to claim | contact original place of purchase (Sky Solar USA) / EG4 support |
Download: EG4 FlexBOSS21 Warranty Document
Manufacturer warranties are provided by the manufacturer. Keep your invoice as proof of purchase. Questions about a warranty claim? Call (888) 831-0450.