Axpert Max II 10kW Main Firmware V56.09 (TMS320F2809)

MAXII10K_DSP_5609.7z

Axpert Max II 10kW Panel Firmware V22.21

Remote Panel_Reflash_MCU(22.21).zip

Here are my first results for firmware version V56.09 (Main) and V22.21 (Panel):

a) This firmware fixes my problem that the inverters very often “forget” their parameters when restarting and then start with the default parameters (this destroyed one of my inverters in the three-phase system).

b) The power management has also improved. In solar-only charging mode, no additional power from the grid is used for charging when the PV output is low. The SUB output strategy also works better now.

c) Unfortunately, the PV input behaves as before. The stuck at 90V and thus a significantly lower yield has not been fixed. The PV control algorithm is also not working properly, the problem described by @Georg594 in Shadow Management still exists.

 

A patch like Coulomb's Version 556.07 (implements a minimum MPPT voltage of 150 V) would be nice (to fix the 90V problem). If he has some time, I would like to ask him for it...

When I look at my diagrams with voltage and power, I can't see any working MPPT control. The PV voltage is often far too high and power is wasted. But, the sun is now low and the PV modules are not really receiving the same amount of light.

 

90V problem, firmware version V56.09

This is patched firmware version x56.09 for the Axpert Max II 10 kW '2809 non-Twin, based on factory firmware version 56.09. That factory firmware's hex file is dated 2023-9-05. Do not use with any other model. Use at your own risk.

This series implements all of Georg594's original patches. They also fix the premature float bug, and report a 5 digit firmware version to monitoring software.

dsp_256.09_patched.hex has a 200V minimum PV voltage.

dsp_556.09_patched.hex has a 150V minimum PV voltage.

dsp_156.09_patched.hex has a 120V minimum PV voltage.

dsp_original.hex is factory firmware version 56.09.

In the zip file, dsp.hex is the same as dsp_256.09_patched.hex, ready to use with the old reflash tool (it only looks for the fixed filename dsp.hex).

Firmware upload instructions for models with a round display.

dsp x56.09 patched Max II 10kW '2809.zip

Hello friends, greetings from Ukraine!
I have an Axioma ISMPPT BFP 8000 inverter. I know that the component base is similar to MPPT Solar, Altek, Qpawer, and I have a question, is it possible to reflash it with firmware to the 11 kilowatt version? I looked at the reviews, the power elements of 8 and 11 kilowatts match. Maybe someone has already done this upgrade?
Can you tell me which firmware is suitable for my inverter. I would be very grateful if someone gives a detailed comment.
Here are photos of the model and the software that it currently has.

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Hello, I am a silent reader and love your work!

Actually I 'm on the way to use this patch as 90V solution:

dsp 281.05 Axpert Max II 8kW patched firmware.zip 281.05

My inverter shows 281.02 firmware. Can or should I use this patch? If not, howto update to 281.05?

MAX II 8kW and 28066 processor, LED ring display

display/MCU/U2:22 12

Edited October 8, 2025Oct 8 by Marintus
I ve read your footer...

On 2025/10/09 at 1:15 AM, Marintus said:

My inverter shows 281.02 firmware.

Is this before or after you updated to what was supposed to be 281.05? I've done a quick check on the 281.05 patched firmware and it seems that it should show 281.05 on monitoring firmware.

If that's how your inverter came, that's really weird. It should update to 281.05 by following the usual update instructions.

The version is the same as when I purchased it. There has not been any change.

The update instruction leads into error as I wrote here "Home > Renewable Energy > Inverters > AXPERT MAX II 8kw firmware > AXPERT MAX II 8kw firmware"

On the USB-stick I renamed MAXII8K 281.05 patched.inv -> mks2.hex . The only file on stick.

After UPG - YES - the diyplay shows U03 in red letters and the blue ring changed to red

What have I done wrong?

On 2024/12/10 at 7:53 AM, Artur said:

I looked at the reviews, the power elements of 8 and 11 kilowatts match. Maybe someone has already done this upgrade?

It would be nice to update to higher power for free, wouldn't it?

But it's hard to tell what subtle changes they have made that makes the 11 kW model deserve its rating. Maybe the printed circuit board tracks are thicker, maybe there is some capacitor that has increased in size, that no-one has noticed.

Certainly, I would not do it, and certainly, doing so would void your warranty.

On 2024/12/10 at 7:53 AM, Artur said:

Can you tell me which firmware is suitable for my inverter.

The latest 81.xx firmware for the Axpert Max II 8 kW '28066 non-Twin is 81.08, available here:

On 2025/11/12 at 2:10 AM, Marintus said:

After UPG - YES - the display shows U03 in red letters and the blue ring changed to red

What have I done wrong?

The manual says that U03 means "Document inside the USB disk with wrong format."

So it might be that the USB stick has the wrong format (FAT32 / NTFS / other), or the file is corrupted, perhaps by not "ejecting" it in Windows before removing it.

Try reading the file with a text editor like notepad. The first three lines should be:

:02000004003DBD
:20800000761B0005ABBDA8BDA0BDC2BDC3BDFF6929425616767EA025761F02929235520166
:20801000EC04923662056F1F56BF08362B35761F01BF1A050002761F02920B36ED14923746

Updating by USB stick seems not to be as robust somehow. Consider using a USB to RS-232 converter.

On 2022/12/15 at 2:06 PM, Coulomb said:

Sadly, no. My notes say that you are blessed with the latest DSP chip ('28066), and the only firmware updates we have are for the older '2809 chip.

The secondary (display) firmware isn't relevant to the "stuck at 90 V" problem, but again you are blessed with the latest display chip (GigaDevice).

Maybe one day we'll learn the secret of patching firmware for one device to become valid firmware for the other device, but at this stage, that's not feasible.

Hi, there is a way now?

Main CPU Firmware Version: 82.02

Thanks!