Solis S6 3kW Hybrid Inverter | S6-EH1P3K-L-PLUS

The Solis S6 3kW Plus, model S6-EH1P3K-L-PLUS, is the entry point to Solis's single-phase S6 Plus hybrids for 48 V batteries. It suits a smaller roof and a home where one battery covers the evening: the panels supply the house first, spare solar charges the battery, and in a power cut the backup circuit is running from the battery in under 10 ms.

With 13.1 A of rated output at 230 V it sits well inside G98's 16 A per phase, so the network operator only needs notifying after commissioning. Solis recommends no more than 6 kWp of panels on it and lets it use up to 4.8 kW of their output at a time; the battery side runs at up to 3 kW and 70 A.

S6 3kW Plus at a glance

What's in the box

Solis lists the contents in section 1.4 of its S6-EH1P(3-8)K-L-PLUS installation manual (v1.2, October 2025); the 3 kW ships with the same kit as the other 3 to 6 kW models.

• The 3 kW inverter with its wall back plate and two fastening screws
• Four expansion bolts to fix the back plate
• Two pairs of MC4 connectors, for one string on each tracker
• An ESCT-TA16-100A/50mA CT clamp with a 5 m lead, which Solis says is compulsory for a hybrid installation
• A Wi-Fi/LAN data stick for SolisCloud monitoring
• A parallel communication cable and four RJ45 connectors
• The quick installation manual
• Battery cables: Solis recommends 2 AWG (roughly 35 mm²) with R38-8 ring terminals, plus a 300 A DC breaker
• The SDM120CTM meter, an optional alternative to the CT, sold separately
• PV cable, grid and backup AC cable, isolators and consumer unit protection

Inverters from Solis's 2024 production came with a Wi-Fi/GPRS stick in place of the Wi-Fi/LAN one; the rest of the kit is unchanged.

Panels and strings

Each of the two MPP trackers takes a single string at up to 16 A working current and 20 A short-circuit. The trackers operate between 90 V and 435 V, the inverter starts up at 90 V, and 500 V is the absolute input limit, so work out each string's open-circuit voltage on the coldest morning and keep it below 500 V.

Two PV figures matter on the 3 kW. 6 kWp is the largest array Solis recommends, double the inverter's rating. 4.8 kW, 160% of the rating, is the most solar power it will process at once, with anything beyond that clipped. To reach that 4.8 kW within the 16 A limit, each string needs to work at 150 V or more, the bottom of the full-load MPPT range. UK arrays seldom produce their full nameplate output, so with 6 kWp fitted the cap mostly matters around midday in the sunniest weeks.

The battery side

Any 40–60 V battery will do, lithium or lead-acid, with the BMS talking to the inverter over CAN or RS485. The 3 kW's 70 A sits comfortably within the IntelliHome 5 kWh's 100 A discharge rating, so a single 5 kWh unit can supply its full 3 kW. If the inverter was made before April 2026, Solis requires a firmware update before it is commissioned with an IntelliHome.

Starting without a battery is fine: select "No battery" during setup and it works as a normal grid-tied solar inverter until one is connected.

Backup, generator and off-grid

The backup output delivers 3 kW continuously and twice that for 10 seconds, enough to get pumps and fridge compressors started. With the grid present, up to 35 A passes straight through to the backup circuit, so those loads can draw more than 3 kW while the grid is on; in a power cut they have to fit within the inverter's 3 kW.

A generator connects to the GEN port, with automatic start and stop control, and the inverter will also run off-grid on solar alone. Existing solar on its own grid-tied inverter can be wired in for export control and to keep working off-grid. Up to six units can be paralleled, and three or more can be set up as a three-phase supply.

Grid approval

Built in

• A PV switch, with ground-fault and residual-current monitoring, anti-islanding and DC reverse-polarity protection
• A 7-inch display and Bluetooth for setup from the Solis app; Wi-Fi/LAN through the supplied stick, with 2G/3G/4G as an option
• Fanless natural-convection cooling, so there is no fan to wear out or whine
• Arc-fault detection (AFCI) is optional on this range, not fitted as standard

On the wall

The 3 kW weighs 23 kg in a 335 × 560 × 253 mm (W × H × D) case and is rated IP66 for indoor or outdoor fitting from −25 °C to +60 °C. Solis wants it out of direct sunlight, which causes derating, and not in a living area where people or animals spend long periods, so a garage, outbuilding or shaded outside wall is the usual home for it.

It hangs upright, within 5° of vertical. Clearances are 300 mm above, 150 mm each side and 500 mm in front, with the bottom at least 800 mm off the floor, or 500 mm if there is no battery cabinet or other heat source below. Solis prohibits mounting two units one directly above the other.

Order alongside

• Solis IntelliHome 5 kWh battery

  Its 100 A rating covers the 3 kW's 70 A.

• IntelliHome 10 kWh battery

  10 kWh from a single wall unit.

• IntelliHome 16 kWh battery

  The biggest IntelliHome, for long evenings.

• IntelliHome 5 kWh accessory pack

  Battery cables and comms leads, if not bought with the battery.

• Warranty to 10 years

  Doubles the standard five-year cover.

• Warranty to 20 years

  Twenty years of cover in total.

Alternative sizes

The other single-phase S6 Plus models share this one's case, 40–60 V battery range and app. Only the 3.6 kW also stays on G98; from 5 kW up, a G99 application must be approved before fitting.

• S6 3.6 kW Plus hybrid inverter

  Up to 7.2 kWp of panels, 80 A to the battery, G98.

• S6 5 kW Plus hybrid inverter

  Up to 10 kWp of panels, 112 A to the battery, G99.

• S6 6 kW Plus hybrid inverter

  Up to 12 kWp of panels, 135 A to the battery, G99.

• S6 8 kW Plus hybrid inverter

  Up to 16 kWp on four strings, 190 A to the battery, G99.

• S6 10 kW Plus hybrid inverter

  Up to 20 kWp, 21 A per string, 210 A to the battery, G99.