Virgo 3K-S: 3 kW single-phase hybrid inverter

Name: Single-phase hybrid inverter Heiwit Virgo 3K-S
Brand: Heiwit
SKU: HEIWIT-3K-S

What is the Virgo 3K-S and who is it for?

The Virgo 3K-S is a 3 kW single-phase hybrid inverter designed for Heiwit sodium-ion batteries. It manages the photovoltaic system, energy storage, the grid and the home’s electrical loads all in a single unit.

It supports up to 8 kW of panels on two independent MPPT trackers, with an input voltage between 100 and 550 V. The two strings can face different directions, for example east and west.

On the energy storage side, it operates at 48 V using Heiwit sodium-ion batteries. Up to three 10 kWh modules can be connected in parallel, giving a total of 30 kWh. The maximum charging and discharging power is 5 kW.

When the grid fails, the integrated UPS function switches over in 10 milliseconds. The backup output delivers 3 kW. From the grid, the inverter can draw up to 32 A to recharge the battery.

The maximum efficiency is 97.6 per cent and the European efficiency is 97.3 per cent. The protection rating is IP66 and the operating temperature range is from −25 °C to +60 °C, with a reduction in power output above 40 °C. Cooling is natural, without fans, and noise levels remain below 25 dB. It is designed for wall mounting.

Monitoring is carried out via the app or the display, using a Wi-Fi, Bluetooth or GPRS connection. The data is stored on servers in Italy. Three units connected in parallel can form a three-phase output; for three-phase loads, Heiwit also offers the Lybra inverter.

The Virgo 3K-S carries the CE marking. It also holds CEI 0-21:2022 certification for connection to the Italian grid, issued by TÜV SÜD. The warranty is 10 years and support is managed directly in Italy. It is sold and installed exclusively through the Heiwit installer network.

Virgo 3K-S: technical specifications

Nameplate data, Virgo 3K-S
Type	Single-phase hybrid inverter with sodium-ion storage
Rated active output power	3 kW
Rated output current	16 A
Output voltage / frequency	230 V (L/N/PE); 50/60 Hz
Maximum photovoltaic input power	8 kW
Maximum photovoltaic voltage	600 V
MPPT	2, one MPPT string, range 100–550 V
Maximum input current for MPPT	16 A
Battery type	Sodium-ion Heiwit, 48 V nominal (range 32–60 V)
Maximum battery charge/discharge power	5 kW (100 A)
Maximum input power from the mains	3,000 W (32 A); 7,360 W to the battery
Nominal backup output power	3 kW
UPS switchover time	10 ms
Maximum efficiency	97.6 per cent
European efficiency	97.3 per cent
MPPT Efficiency	99.9 per cent
Degree of protection	IP66
Operating temperature	from −25 °C to +60 °C (reduced performance above 40 °C)
Maximum altitude	4,000 m (reduction above 2,000 m)
Cooling	Natural, noise level below 25 dB
Standby power consumption	less than 10 W
Parallel connection	Up to 3 units
Communication	RS485 and CAN (battery); RS485 (meter); Wi-Fi + Bluetooth; GPRS
Display	LCD and apps
Installation	Wall mounting
Dimensions (W × H × D)	510 × 450 × 186 mm
Net weight	22.6 kg
Compliance	IEC 62109-1:2010; IEC 62109-2:2010; EN/IEC 61000-6-1:2019; EN/IEC 61000-6-3:2021; EN 62920:2017/A1:2021
Network certifications	CEI 0-21:2022; VDE-AR-N 4105:2018; DIN VDE V 0124-100:2020
Warranty	10 years, support in Italy

Download the datasheet (PDF)

CEI 0-21 certification by TÜV SÜD (PDF)

VDE-AR-N 4105:2018 unit certificate by TÜV SÜD (PDF)

VDE-AR-N 4105:2018 network and system (NS) protection certificate by TÜV SÜD (PDF)

Data declared by the manufacturer in the datasheet; the actual parameters are those of the product as delivered.

Virgo 3K-S: frequently asked questions

Which batteries is the Virgo 3K-S compatible with?

Only 48 V Heiwit sodium-ion batteries, with up to 3 units connected in parallel for a storage capacity of 30 kWh, and a maximum charge and discharge power of 5 kW.

Does it work during a power cut?

Yes. The built-in UPS function switches from mains to battery power in 10 ms and supplies up to 3 kW of backup power.

How much photovoltaic capacity can I connect to the Virgo 3K-S?

Up to 8 kW input power across 2 MPPT channels with a range of 100–550 V, one string per MPPT channel, maximum voltage 600 V.

Can it be used on a three-phase supply?

The Virgo is single-phase; three units connected in parallel can provide a three-phase output. For three-phase loads, Heiwit also offers the Lybra hybrid inverter.

Can it be installed outdoors?

Yes. The protection rating is IP66 and the operating temperature ranges from −25 °C to +60 °C, with a reduction in power output above 40 °C. Wall-mounted, naturally cooled, with a noise level of less than 25 dB. The battery, however, must only be installed indoors.

Is the Virgo 3K-S CEI 0-21 certified?

Yes. The Virgo 3K-S with the Heiwit battery is CEI 0-21 certified by TÜV SÜD on the basis of type testing (document no. D 132944 0003). It also carries the CE marking.

Is the Virgo 3K-S certified for the German grid?

Yes. The Virgo 3K-S has VDE-AR-N 4105:2018 certification, issued by TÜV SÜD in September 2026. This is the standard for connection to the German low-voltage grid. There are two certificates: the unit certificate (no. ESY 132944 0008) and the certificate for the network and system (NS) protection integrated in the inverter (no. ESY 132944 0009). The tests follow DIN VDE V 0124-100:2020.

Who is responsible for the warranty and after-sales service?

Heiwit, directly in Italy, with a 10-year warranty. Monitoring data is stored on Italian servers and the inverter is sold and installed only through the Heiwit installer network.