Can Solar Panels Plug Straight Into an EG4 GridBOSS?
Summary
The GridBOSS spec sheet lists no DC input for panels. Its ports are for the utility, a generator, backed-up and non-backed-up loads, three hybrid inverters and four smart ports, and every one of them is rated 120/240 VAC. The panels' DC and the MPPT tracking are handled by the hybrid inverter, such as the FlexBOSS21 or 18kPV.
GridBOSS ratings (spec sheet v1.1.8)
EG4 calls GridBOSS a microgrid interconnect device (MID), a single point of connection for the utility, hybrid inverters, generators, smart loads and AC-coupled inverters.
| Item | Rating |
|---|---|
| Grid, backup and non-backup | 200 A each, 120/240 VAC |
| Hybrid inverter ports | 3, up to 90 A per port |
| Smart ports (AC coupling or load control) | 4, rated 125 A, 80 A, 60 A and 60 A |
| Generator | up to 125 A |
| Transfer time | about 25 ms |
| Idle consumption | about 55 W |
| Size and weight | 800 × 500 × 178 mm, 25 kg |
| Enclosure and warranty | NEMA 3R, 10 years |
The spec sheet lists the EG4 12kPV, 18kPV, FlexBOSS18 and FlexBOSS21 as supported inverters and says third-party inverters are not supported and cannot be connected to the hybrid ports. The breaker sizes it gives for those ports are 50 A for the 12kPV, 70 A for the 18kPV and FlexBOSS18, and 90 A for the FlexBOSS21.
The panel-side numbers belong to the inverter
| Item | FlexBOSS21 | 18kPV |
|---|---|---|
| MPPTs | 3 | 3 |
| Current per MPPT | 26 A, 26 A, 15 A (rated) | 25 A, 15 A, 15 A (max usable) |
| Short-circuit current per MPPT | 31 A, 31 A, 19 A | 31 A, 19 A, 19 A |
| Max DC input voltage | 600 V | 600 V |
| Recommended max solar array | 21 kW | 21 kW (18 kW max utilized) |
| Continuous AC output | 16 kW (12 kW on battery only) | 12 kW at 240 V |
| Battery voltage | 51.2 V | 48 V |
Three FlexBOSS21 units at their 66.7 A maximum continuous output add up to about 200 A, the same as the GridBOSS backup-side limit. How to string the panels and which equipment can be paired are not something we judge; that follows each manufacturer's specifications.
Shopping for one? Browse home backup power stations →
Sources
- EG4 Electronics — GridBOSS
- EG4 Electronics — GridBOSS Spec Sheet (VERSION 1.1.8, 2026-06-17)
- EG4 Electronics — FlexBOSS21
- EG4 Electronics — FlexBOSS21 Spec Sheet (VERSION 1.3.0)
- EG4 Electronics — 18kPV
- EG4 Electronics — 18kPV Spec Sheet (VERSION 1.4.3)
We have not tested these products. Specs, prices, stock and terms are as published on these pages on the date above and can change; check the manufacturer or retailer before you buy.