Solax Hybrid X1/X3 G3/G4 (battery)
The Solax Hybrid X1/X3 G3/G4 is a solar hybrid inverter family covering single-phase and three-phase residential and light-commercial installations with integrated battery storage support. This ModbusCloud template communicates over Modbus RTU via the inverter's RS-485 COM port and reads battery power flow and state of charge, while also exposing three holding registers that control battery operating mode. The Q.HOME ESS HYB-G3 is an OEM variant covered by the same register map. With live battery data and remote mode control in one template, installers can monitor storage health and adjust charge behaviour directly from the ModbusCloud portal.
- Protocol
- Modbus RTU
- Connection
- RS485
- Registers
- 5, read and write
- Brand
- Solax
- Compatible models
- Hybrid X1/X3 G3/G4 · Q.HOME ESS HYB-G3
- Last updated
Registers (5)
2 read, 3 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| power | W | Read | |||
| soc | % | Read | |||
| batterymode_a | Write | ||||
| batterymode_b | Write | ||||
| batterymode_d | Write |
Loading registers…
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Use cases
- Monitor battery state of charge continuously to detect unexpected overnight depletion and size storage correctly.
- Track instantaneous battery power to verify that charge and discharge cycles follow the expected daily PV generation pattern.
- Alert on battery power readings that remain at zero during expected charging hours, indicating a BMS or wiring fault.
- Compare state of charge across multiple Solax sites in the multi-site overview to benchmark battery utilisation rates.
- Write battery mode setpoints remotely to switch between self-use and feed-in priority without visiting the installation.
Installation
Enable Modbus RTU on the inverter: navigate on the inverter display to Settings, then Advanced Settings, then Modbus, set the slave address (default 1) and confirm the baud rate is set to 19200.
Connect the ModbusCloud Gateway RS-485 terminals to the inverter COM port (RJ45): use pin 4 (blue wire) for the A lead and pin 5 (white-blue wire) for the B lead. Do not connect the COM port to an Ethernet switch.
In the ModbusCloud portal, add the Gateway, import the Solax Hybrid X1/X3 G3/G4 (battery) template, assign the unit ID matching the inverter slave address, and set the baud rate to 19200 with 8N1 framing.
Verify the connection by reading the soc register (address 301) in the live data view and confirming the value matches the percentage shown on the inverter display.
Things to watch for
The Gateway connects but all register values are zero or absent.
Modbus RTU is disabled by default on G4 models. Go to Settings, Advanced Settings, Modbus on the inverter display and confirm Modbus is active. Also check that holding register 0x013E (485CommFunSelect) is set to 0 for Modbus mode, not 1 for EV Charger mode.
RS-485 wiring is connected but no data appears after enabling Modbus.
RS-485 polarity is critical on Solax inverters. Confirm pin 4 (blue wire) connects to the A lead and pin 5 (white-blue wire) to the B lead on your adapter. Also verify that only one Modbus master is on the bus; a second master such as a Wi-Fi dongle or another integration will cause collisions and silent read failures.
Battery power reads plausible values but the sign seems inverted.
The power register (address 297) is a signed int16. Positive values indicate charging and negative values indicate discharging. If your portal shows the opposite, check whether a scaling or sign inversion is applied in your data pipeline before raising a hardware fault.
Is it safe to write to the batterymode registers frequently for automation?
No. The Solax holding registers used for battery mode control (addresses 31, 32, and 86) are stored in EEPROM, which has a limited write cycle life. Frequent automated writes, such as switching mode every few minutes, can degrade the EEPROM irreversibly. Restrict writes to genuine mode changes and avoid polling these registers with write commands on a short interval.
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