Hello,

I have an Axpert VM III-4000 TWIN inverter and I would like to update both U1 and U2 firmware versions.

I am experiencing a problem where the screen suddenly glitches: all icons and the battery indicator disappear for a few moments, accompanied by a warning buzzer and a red alarm light. This issue happens several times daily.

The current version is:

U1: 60.10

U2: 57.17

Please help me solve this problem.

Thank you.

On 2026/05/09 at 10:40 PM, yassen said:

I am experiencing a problem where the screen suddenly glitches: all icons and the battery indicator disappear for a few moments, accompanied by a warning buzzer and a red alarm light. This issue happens several times daily.

Does it usually happen when the PV is working at high power? If so, it may be that you need the capacitor modification.

Having the indicators disappear and glitch like that sounds more like either interference from unfiltered PV and/or wrongly dressed cables, rather than a firmware issue. It could also be faulty or corroded connectors or cables, but this doesn't seem to be common. It could also be a power supply issue inside the display, e.g. electrolytic capacitors dried out. But again this doesn't seem to be common.

On 2026/05/09 at 10:40 PM, yassen said:

U1: 60.10

U2: 57.17

Main firmware version 60.10 is the latest 60.xx firmware in my collection.

Display firmware version 57.22 is the latest 57.xx firmware I know of. I don't see it elsewhere, so I'll post it here.

This is factory display firmware version 57.22 for the Axpert King II (NOT King 1 with 145 V max PV) or Axpert VM III, Twin models. Do not use with other models. Use at your own risk. The hex file is dated 10th December, 2025.

This firmware does process the QDOP command, so with suitably recent main firmware, it should support SoC% for settings 12,13, and 29 when connected to a suitable battery's BMS.

Remote Panel_Reflash_MCU(57.22).rar

Edited May 13May 13 by Coulomb

Hi everyone,

Hi @Coulomb,

I’m struggling to get stable BMS communication working between my Axpert inverter and my LiFePO4 battery.

Here are my exact specs and current versions (photos of sticker and firmware attached):

• Inverter Model: Axpert VM III-4000 TWIN (24V)

• Main CPU Firmware (U1): 60.06

• Secondary CPU/Display Firmware (U2): 57.09

• Battery: SEC Smart Energy 25.6V 200Ah LiFePO4.

Battery Port Definition (From Manual):

• RS485A Port: Pin 1,8 = RS485-B | Pin 2,7 = RS485-A | Pin 3,6 = GND.

• CAN Port: Pin 4 = CAN-L | Pin 3 = CAN-H | Pin 5 = GND.

What I have tried so far:

I have already made a custom RJ45 cable and literally tested every possible pinout combination based on these specs. Unfortunately, absolutely nothing worked, and the communication just won't establish.

Since the physical cable combinations have been fully exhausted, I strongly suspect this is a firmware issue. Either my current U2 version (57.09) lacks the proper protocol for this battery, or there's a compatibility bug with this Twin model.

Could anyone advise if there is a safe, updated U2 (or U1) firmware for my exact 4kW Twin model that can resolve this?

Thanks a lot for your time and help!

Ah, you actually have 60.06. It seems that the latest 60.xx firmware is 60.10 (also available as x60.xx patched). But if you need the quiet fans, stick to 60.95, or its patched versions x60.96 (note the difference in the last digit; I erred with x60.95 and the fixed code is now called x60.96, even though it's still based on factory firmware version 60.95).

The display / BMS comms is likely the firmware that needs to be changed, however.

The latest (of two) 57.xx display firmwares I have is 57.22. [ Edit: Oops, I now see that's just above in this thread. I just search once I know the firmware version. ]

Edited 11 hours ago11 hr by Coulomb

Is version 57.22 stable? I need the file, please. Axpert VM III-4000 TWIN inverter.