FoxESS + Fronius Wattpilot

What Zerofy can do with FoxESS and Fronius Wattpilot

In practice

• Zerofy adjusts the charging current of your Wattpilot but doesn’t switch phases. On a three-phase connection, solar charging needs at least about 4.1 kW of surplus (6 A × 3 × 230 V); on a single-phase connection about 1.4 kW.
• A typical FoxESS home system (2.5–15 kW) needs a sunny midday to reach the 4.1 kW three-phase minimum. Wired single-phase, the charger starts from about 1.4 kW but charges at no more than about 3.7 kW.
• Zerofy gets new FoxESS data every 5 minutes and adjusts accordingly. A minimum runtime and an activation threshold in Autopilot keep passing clouds from interrupting charging.
• Zerofy also shows your FoxESS battery, so you can see whether surplus goes into the battery or into the car.
• If your car is connected to Zerofy too, turn on Autopilot for either the car or the charger, not both.
• In its own surplus mode the Wattpilot starts at 1.38 kW on one phase, adjusts in 0.23 kW steps and switches to three phases above 4.14 kW, where it steps in 0.69 kW; the switching level can be changed in the app. Via OCPP, Zerofy sets the charging power but not the phases, so the minimum is 6 A: about 1.4 kW single-phase or 4.1 kW three-phase.

What FoxESS and Fronius Wattpilot offer on their own

FoxESS: FoxESS sells its own AC wallboxes. Paired with a FoxESS inverter and meter, FoxCloud 2.0 offers PV Linkage with a Green Mode (solar only) and an Economic Mode (solar first, grid keeps it at 6 A when solar is short), adjusting the charging current between 6 and 32 A.

Fronius Wattpilot: The Wattpilot’s own PV surplus charging needs a Fronius inverter (GEN24, Verto, or SnapINverter/IG with Datamanager 2.0) with a Fronius Smart Meter at the feed-in point, talking over the Solar API in the same network. Other inverter brands only work with an extra Fronius Smart Meter IP or Datamanager Box 2.0 plus Smart Meter; the Wattpilot then also appears in Fronius Solar.web.

Zerofy connects the two: it reads FoxESS production and controls your Wattpilot to match, together with your other devices in one app, with dynamic tariffs and forecast-based Smart mode.

Setting up FoxESS and Fronius Wattpilot in Zerofy

1. Connect FoxESS

Zerofy connects to the FoxESS cloud: you log in with your FoxESS Cloud account and authorize access on FoxESS’s own screen.

1. Make sure your inverter is online and registered in the FoxESS Cloud app.
2. In Zerofy, choose FoxESS and log in with the FoxESS Cloud owner account.
3. Confirm your devices on the FoxESS authorization screen.

Good to know: Use the owner account of the device. Installer and agent accounts don’t own the devices, so FoxESS shows “No Devices” and the connection fails.

Step-by-step guide for FoxESS

2. Connect Fronius Wattpilot

The Wattpilot connects to Zerofy via OCPP 1.6J; you enter the connection details from Zerofy in the Solar.wattpilot app.

1. In Zerofy, add a Fronius Wattpilot and copy the OCPP connection details.
2. In the Solar.wattpilot app, go to Internet → OCPP and enter the details.
3. Save and wait until the status shows the connection is established.

Step-by-step guide for Fronius Wattpilot

3. Turn on Autopilot

In Zerofy, open your Wattpilot, turn on Autopilot and choose Solar – or Smart to also use dynamic tariffs and forecasts. Set the priority, activation threshold and minimum runtime.

Dynamic tariffs

Zerofy can also run your Wattpilot on dynamic electricity prices (EPEX Spot or Nord Pool, e.g. Tibber or aWATTar) or on a fixed time-of-use tariff. Smart mode combines those prices with forecasts of your household consumption and your FoxESS solar production.

Learn more about Smart Mode

About FoxESS and Fronius Wattpilot

FoxESS – Fox ESS is a Chinese inverter and storage maker founded in 2019 and headquartered in Wenzhou. Homes typically have the single-phase H1/AC1 (2.5–6 kW) or KH (7–10.5 kW) hybrid inverters or the three-phase H3 Smart (5–15 kW), with EP, EQ or ECS batteries. Monitoring app: FoxCloud 2.0.

Fronius Wattpilot – The Wattpilot is the EV charger of the Austrian inverter maker Fronius, built for solar charging with automatic 1/3-phase switching and surplus charging from 1.4 kW. The Flex has LAN and Wi-Fi, a §14a input and a Pro version with MID and Eichrecht; it is mainly sold through installers. Products: Fronius Wattpilot Flex Home, Wattpilot Flex Pro, Wattpilot Go, Wattpilot Home.

Manufacturer information last checked: October 2026.

All devices that work with FoxESS