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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
- 14.3kWh or 16kWh LFP per battery
- UL 9540 ESS listed with WallMount Indoor
- 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 314Ah Indoor Battery Spec Sheet (v1.0.4)
- EG4 FlexBOSS21 Hybrid Inverter User Manual (v1.3.7)
- EG4 WallMount 314Ah Indoor Battery User Manual (v1.0.4)
- EG4 FlexBOSS21 Warranty Document
- EG4 WallMount 314Ah Battery Warranty Document (Indoor & All Weather)
- EG4 WallMount 314Ah Indoor Battery Quick Start Guide (v1.0.6)
- EG4 Parallel 314Ah & 280Ah Batteries Guide (v1.1)
Build a whole-home solar and storage system around EG4's flagship FlexBOSS21 hybrid inverter and EG4 Indoor WallMount batteries. Choose one or two inverters and one to six batteries (280Ah or 314Ah). Each configuration includes the matching conduit boxes and paralleling kits, so the install comes together cleanly.
Highlights
- FlexBOSS21: 16kW AC with PV and grid, 12kW battery-only, 21kW PV input
- Starts big loads such as 5-ton AC units
- Grid-tied with sell-back, backup, or off-grid operation
- Indoor WallMount batteries with self-heating and an advanced BMS
- GridBOSS-ready for whole-home load management (sold separately)
What's included
- 1–2× EG4 FlexBOSS21 hybrid inverter (per selection)
- 1–6× EG4 Indoor WallMount battery, 280Ah or 314Ah (per selection)
- EG4 280Ah/314Ah Buildable 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 battery | 51.2V, 16kWh |
| 280Ah battery | 51.2V, 14.3kWh |
Warranty & shipping
- EG4 warranties: FlexBOSS21 10 years, WallMount batteries 10 years
- Shipping weight is set for each configuration (about 403 lbs to 2,126 lbs). Ships by freight
Solar panels not included. Professional installation is recommended.
| Manufacturer | EG4 Electronics (bundle) |
|---|---|
| Bundle SKU | BNDL-E0023-1-1-1 |
| 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 Indoor Battery 48V 314Ah 16kWh (LiFePO4 (LFP); 51.2 VDC; 314Ah) |
Specifications are from the manufacturer and may change. Questions? Call (888) 831-0450.
EG4 Limited Warranty (per component): FlexBOSS21 10-year limited; WallMount 314Ah 10-year or 10,000 cycles (whichever first), prorated
| FlexBOSS21 | 10-year limited |
|---|---|
| WallMount 314Ah | 10-year or 10,000 cycles (whichever first), prorated |
| How to claim | contact original place of purchase (Sky Solar USA) / EG4 |
Download: EG4 FlexBOSS21 Warranty Document
Download: EG4 WallMount 314Ah Battery Warranty Document (Indoor & All Weather)
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 + 1 x EG4-314Ah WallMount Battery, 1 EG4 FlexBOSS21 + 2 x EG4-314Ah WallMount Battery, 1 EG4 FlexBOSS21 + 3 x EG4-314Ah WallMount Battery, 2 EG4 FlexBOSS21 + 4 x EG4-314Ah WallMount Battery, 2 EG4 FlexBOSS21 + 6 x EG4-314Ah WallMount Battery, 1 EG4 FlexBOSS21 + 1 x EG4 280Ah WallMount Battery, 1 EG4 FlexBOSS21 + 2 x EG4 280Ah WallMount Battery, 1 EG4 FlexBOSS21 + 3 x EG4 280Ah WallMount Battery, 2 EG4 FlexBOSS21 + 4 x EG4 280Ah WallMount Battery, 2 EG4 FlexBOSS21 + 6 x EG4 280Ah WallMount Battery |
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