Hello, I updated my VM II 3K (24V) to firmware 43.28 and charging stopped. I need to roll back to U1 43.15. Does anyone have the hex file?"

Edited May 13May 13 by almusarrej

2 minutes ago, almusarrej said:

Hello, I updated my VM II 3K (24V) to firmware 43.28 and charging stopped. I need to roll back to U1 43.15. Does anyone have the hex file?"

1 hour ago, almusarrej said:

I updated my VM II 3K (24V) to firmware 43.28 and charging stopped. I need to roll back to U1 43.15.

Unfortunately, the 43.xx firmware version number range is a combination of VM II, VM III, and VM II premium firmwares, with VM II Premium firmwares starting at about 43.22 (possibly 43.20 was the first one). The 43.xx firmware series seem to have drifted from VM II (where the display is driven by the DSP) to VM III (where the display is external). My guess is that you've applied the VM II Premium firmware 43.28 to your early VM III non-Twin.

Alas, my 43.xx firmwares are a bit jumbled, so it will take me a while to sort them out. I don't have any 43.xx that is anywhere near 43.15 though. Are you sure that your inverter came with 43.15, and not say 41.15?

Yeah, I'll get you a picture.

Having sorted out the mess that is the 43.xx firmware number range, I came across three newer (to me) 43.xx firmwares. The latest of these is 43.29, two days later than 43.28. Perhaps they noticed a whoopsie with the charging and updated the firmware quickly as a result.

This is main (U1) factory firmware version 43.29 for the Axpert VM II Premium 3kW and 2.5kW '28062 non-Twin. Do not use with any other model or version.

Use at your own risk. The hex file is dated 16/1/2025.

Firmware upload instructions for models with a removable display.

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

The rar file password is "flash" without the quotes.

VMII_Premium_2K5_3K_MAIN_Reflash_Ver43.29 pw flash.rar

Edited Tuesday at 11:133 days by Coulomb

Thanks.. Thanks. I'll install and call you the result