SAJ + Huawei SCharger

What Zerofy can do with SAJ and Huawei SCharger

In practice

• Zerofy adjusts the charging current of your Huawei SCharger 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 SAJ home system (3–10 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 SAJ 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 SAJ 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 Huawei’s own mode, the 22KT charges three-phase from about 4.14 kW and drops to single-phase below that if “Switch Between Single and Three Phases” is on; it then charges on L1 only, so Huawei advises wiring L1 to the least-loaded phase. Via OCPP, Zerofy sets the power but not the phases, so the minimum is 6 A: about 1.4 kW single-phase or 4.1 kW three-phase.

What SAJ and Huawei SCharger offer on their own

SAJ: SAJ’s Caro wallbox (7 kW, 6–32 A, or 11 kW, 6–16 A) can charge from solar and supports OCPP 1.6J. The manual says PV charging needs an SAJ H2+B2, HS2, AS2 or HS3 storage system plus the eManager.

Huawei SCharger: Huawei’s own surplus mode is “PV Power Preferred” in FusionSolar. It needs a Huawei SUN2000 inverter and a Huawei Smart Power Sensor at the grid connection (DTSU666-FE directly, or an RS485 meter such as DTSU666-H relayed by the WLAN/FE Smart Dongle) and does not work in charger-only setups.

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

Setting up SAJ and Huawei SCharger in Zerofy

1. Connect SAJ

Zerofy reads your plant from the SAJ cloud: you add Zerofy as a developer in the Elekeeper app and then enter your Plant ID in Zerofy.

1. In the Elekeeper app, tap ••• and open Plant Management.
2. Under Developer/Partner, paste the Developer ID shown in Zerofy and confirm access.
3. Copy your Plant ID from Plant Management and paste it into Zerofy.

Good to know: How fresh the data is depends on how often the SAJ cloud updates. For the battery, Zerofy supports forced charging but not switching the battery mode.

Step-by-step guide for SAJ

2. Connect Huawei SCharger

The SCharger connects to Zerofy via OCPP, which is set in installer mode of the Huawei Fusion app; Zerofy can then start, stop and set the charging power.

1. Update the charger to FusionCharge V100R023C10SPC220 or later (OTA via the app).
2. In Zerofy, add a Huawei SCharger and copy the OCPP link (ocppconnect.net/<id>).
3. In the Fusion app, connect to the charger’s Wi-Fi, log in with Installer Mode and open OCPP.
4. Choose “Insecure transmission with basic authentication” and enter domain ocppconnect.net, port 80, path and username <id>, and any password.

Good to know: OCPP can only be set in installer mode, so many owners need their installer for the one-time setup. Older firmware must be updated first.

Step-by-step guide for Huawei SCharger

3. Turn on Autopilot

In Zerofy, open your Huawei SCharger, 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 Huawei SCharger 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 SAJ solar production.

Learn more about Smart Mode

About SAJ and Huawei SCharger

SAJ – SAJ (Guangzhou Sanjing Electric) is an inverter maker from Guangzhou, China. Homes usually have the H2 hybrid inverter with B2 battery or the HS2, HS3 or AS2 all-in-one storage systems; the eManager unit and the Caro wallbox tie them together. Monitoring app: Elekeeper.

Huawei SCharger – The SCharger is the wallbox of the Chinese inverter maker Huawei (7.4 kW single-phase or 22 kW three-phase), the natural choice for homes with a Huawei inverter. It is sold through solar installers and is set up and monitored in FusionSolar. Products: SCharger-7KS-S0, SCharger-22KT-S0.

Manufacturer information last checked: October 2026.

All devices that work with SAJ