Press the or DOWN buttons until you see the screen showing "U1" followed by a number (e.g., U1 41 02 ). U1 represents the Main CPU (Inverter) firmware.
Firmware is the "brain" of your inverter. Manufacturers release updates to address several key areas:
Updates resolve common "Error 08" (bus start fail) issues or "Error 09" (soft start fail) glitches caused by software timing.
Once the tool says "Update Successful," the inverter will restart. Re-check the U1/U2 screens to confirm the new version. Critical Safety Warning
Do not attempt an update if your batteries are low or if there's a risk of a power cut. If the inverter loses power during a flash, it may "brick."
Newer firmware versions often include improved protocols for communicating with Pylontech, Dyness, and other popular lithium batteries via the RS485 or CAN port.
Voltronic Power typically provides firmware to distributors rather than hosting a public download portal. To find the latest version:
If possible, ensure your loads are powered by the grid or turned off.
Try a different USB cable or a different laptop. Inverters are notoriously picky about Serial-to-USB chipsets (FTDI chips are recommended).