A researcher found that the MIC600T-LX inverter has exactly the same hardware as the larger units such as the MIC2000T-LX inverter. As there were no physical differences in the hardware, they dug into the software and were able to find a register in the Modbus protocol used by the inverter that determines the actual mode/output power limit of the specific unit. Interestingly, this mode is not only readable but also writable by the user.
Warning: The following steps are at your own risk! I am not responsible for any damage caused by the following information.
If your inverter is associated with your Growatt account, you can change the relevant value directly in the cloud-based WebUI. After logging in to the platform, select the inverter you want to change and go to the PV system settings. The same options seem to be available from the ShinePhone app but I have not tried this.
First, we want to make sure that the inverter is set to standby mode by setting register 0 to value 0. The key to save the settings on the devices is the text “growatt” followed by the current date in the form of “yyyymmdd”. If the current date is 31.07.2023, the key would be “growatt20230731”.
Once you’ve entered and saved the first value, confirm the status of the inverter by checking the text in the display on the inverter. If the display shows the text “Standby”, you’re good to continue with the next steps.
The second step is to set the so-called mode of the device, represents the maximum output level of the device. These modes correspond to the different models of the inverters on the market. The following modes / values are possible:
- 600W = Value 6
- 750W = Value 7
- 1.000W = Value 10
- 1.500W = Value 15
- 2.000W = Value 20
Once we’ve decided which limit we want to set, we update register “121” with the appropriate value from the list above.
The third step is to disable the standby mode. This is done by setting the register “0” to the value “0”. Once this is done, restart the inverter by power cycling it.
That’s it! Your inverter has now neem upgraded to a higher power output.