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Ships by freight. This item is too large for parcel delivery. After you order, we'll contact you within 1 business day with the freight cost and delivery options (liftgate, residential). Your order ships only after you approve the quote.
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- 16kW AC with PV, 12kW from battery
- 21kW PV input, 3 MPPTs
- Outdoor-rated: NEMA 4X inverter, IP65/IP67 batteries
- UL 9540 ESS listed with WallMount All Weather
- GridBOSS-ready for whole-home backup
- 10-year warranty on inverter and batteries
Ships by LTL freight. Too large for parcel delivery. Questions on freight? Call (888) 831-0450.
We accept
Product Documents
- EG4 FlexBOSS21 Hybrid Inverter Spec Sheet (v1.3.0)
- EG4 WallMount All Weather 280Ah (14.3kWh) Battery Spec Sheet (v1.2.1)
- EG4 FlexBOSS21 Hybrid Inverter User Manual (v1.3.7)
- EG4 WallMount 280Ah All Weather Battery User Manual (v1.6.3)
- EG4 FlexBOSS21 Warranty Document
- EG4 14.3kWh WallMount All Weather Battery Warranty Document
- EG4 Parallel 314Ah & 280Ah Batteries Guide (v1.1)
A fully outdoor-capable whole-home system: the FlexBOSS21 hybrid inverter paired with EG4 AllWeather WallMount batteries. Choose one or two inverters and one to six batteries (280Ah or 314Ah). All Weather conduit boxes and paralleling kits are included to match, so the whole install can live on an exterior wall and save indoor space.
Highlights
- FlexBOSS21: 16kW AC with PV and grid, 12kW battery-only, 21kW PV input
- Outdoor-rated batteries with internal heating
- Grid-tied with sell-back, backup, or off-grid operation
- Expandable to large multi-inverter systems
What's included
- 1–2× EG4 FlexBOSS21 hybrid inverter (per selection)
- 1–6× EG4 AllWeather WallMount battery, 280Ah or 314Ah (per selection)
- EG4 280Ah/314Ah All Weather Conduit Box, one per battery
- EG4 280Ah/314Ah WallMount Paralleling Cable Kit, one per additional battery
Component specs
| FlexBOSS21 output | 16kW (PV + grid) / 12kW (battery only) |
| FlexBOSS21 PV input | 21kW, 600VDC, 3 MPPTs |
| 314Ah AllWeather battery | 51.2V, 16kWh, IP67 |
| 280Ah AllWeather battery | 48V, 14.3kWh, IP65 |
Warranty & shipping
- EG4 warranties: FlexBOSS21 10 years, WallMount batteries 10 years
- Shipping weight is set for each configuration (about 430 lbs to 2,096 lbs). Ships by freight
Solar panels not included. Professional installation is recommended.
| Manufacturer | EG4 Electronics (bundle) |
|---|---|
| Bundle SKU | BNDL-E0022-1-1 |
| Configurations | 10 variants (1-2 inverters, 1-6 batteries; 280Ah or 314Ah) |
| Includes | 1x EG4 FlexBOSS21 Hybrid Inverter (16kW (66.7A); 12kW (50A); 21kW (STC)) |
| Includes | 1x EG4 WallMount All Weather Battery 48V 280Ah 14.3kWh (LiFePO4; 51.2V; 280Ah) |
Specifications are from the manufacturer and may change. Questions? Call (888) 831-0450.
EG4 Limited Warranty (per component): FlexBOSS21 10-year limited; WallMount AW 280Ah 10-year limited, prorated
| FlexBOSS21 | 10-year limited |
|---|---|
| WallMount AW 280Ah | 10-year limited, prorated |
| How to claim | contact original place of purchase (Sky Solar USA) / EG4 |
Download: EG4 FlexBOSS21 Warranty Document
Download: EG4 14.3kWh WallMount All Weather Battery 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.
| Battery Options |
1 EG4 FlexBOSS21 + 1x EG4 280Ah All Weather WallMount, 1 EG4 FlexBOSS21 + 2x EG4 280Ah All Weather WallMount, 1 EG4 FlexBOSS21 + 3x EG4 280Ah All Weather WallMount, 2 EG4 FlexBOSS21 + 4x EG4 280Ah All Weather WallMount, 2 EG4 FlexBOSS21 + 6x EG4 280Ah All Weather WallMount, 1 EG4 FlexBOSS21 + 1x EG4 314Ah All Weather WallMount, 1 EG4 FlexBOSS21 + 2x EG4 314Ah All Weather WallMount, 1 EG4 FlexBOSS21 + 3x EG4 314Ah All Weather WallMount, 2 EG4 FlexBOSS21 + 4x EG4 314Ah All Weather WallMount, 2 EG4 FlexBOSS21 + 6x EG4 314Ah All Weather WallMount |
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