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Compatibility · Ready for GridZeno

SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV with GridZeno.

Large grid inverters without a battery. GridZeno shows the solar production on an X3-MEGA G2 and X3-FORTH but can't control anything on them. Applies to X3-MGA-20K to 60K-G2, X3-FTH-40K to 150K, FTH80T to 125T and X3-GRD-300K to 350K-HV.

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What GridZeno can do on SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV

SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV on the compatibility list, updated 31 October 2026.

  • Live overview of solar, consumption and gridAll subscriptions · Solar production only. The dongle can't read a FORTH G3 or an X3-GRAND HV yet.
    Works
  • Battery state of chargeAll subscriptions · requires a battery · The grid inverter has no battery.
    Not possible
  • Stop selling at negative pricesSmart and Pro · The inverter only has a limit for the whole output, and the dongle doesn't use it yet.
    Coming later
  • Charge from the grid when power is cheapSmart and Pro · requires a battery
    Not possible
  • Discharge the battery when power is expensivePro · requires a battery
    Not possible

Works: tested and measured on real hardware.

02

How the inverter is controlled

The dongle reads the inverter and never writes anything to it.

What GridZeno reads
Solar production on an X3-MEGA G2 and X3-FORTH. Grid and consumption aren't shown. The dongle can't read a FORTH G3 or an X3-GRAND HV yet.
Battery
None. The inverter is a grid inverter without a battery, so there's nothing to charge or sell from.
Grid export
The inverter only has a limit for the whole output, and the dongle doesn't use it yet.
Manual means no switching
When the control is on Manual, GridZeno calculates the plan and shows it, but changes nothing on the inverter.
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What is special about the SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV

The serial number is in input 0x32, not in holding 0x00: X3G04, X3G05, X3G06, X3G075, X3G08, X3G01, A3F10 or MAXMEG_G2. The X3-FORTH G3 and X3-GRAND HV have no public register map and aren't recognised yet.

What the dongle reads
The AC power in 0x183, today's and the total production in 0x189 and 0x18A, the temperature in 0x202 and all 12 MPPTs from 0x28D in one read of 84 registers.
Byte order
High word first, the opposite of SolaX' other maps.
Limits
No meter and no battery. The power limit in 0x2304 limits the whole output and isn't used.

How it differs from its neighbours

  • SolaX X3-PRO: The X3-PRO G2 is read in another range and has a meter from 0x43B.

From the dongle's firmware and our notes on each inverter, not from the datasheet.

04

How to connect the dongle

Wires in the inverter's terminal plug. Approx. 30 minutes.

Port
COM (30-pin connector)
Pin
A at pin 1 (RS485A IN+), B at pin 2 (RS485B IN-), GND at pin 3 (IN-GND (reserved on X3-FORTH))
Where
The round, waterproof COM connector on the underside of the inverter, by the Dongle port. The same connector is used for energy meter and DRM, so there may already be wires in it.

See the full installation guide for SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV

GridZeno Dongle for SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV

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Before you buy

This one works.

SolaX X3-MEGA G2, X3-FORTH, FORTH G3, X3-GRAND HV is the inverter GridZeno has been tested on. Check that your model is under X3-MGA-20K to 60K-G2, X3-FTH-40K to 150K, FTH80T to 125T and X3-GRD-300K to 350K-HV. If it still doesn't suit you, you have 100 days' free return.

Buy now See the subscriptions