Where can I find a list of all compatible firmware for an inverter?

 

I have been trawling the internet for information about the firmware used in my inverter, but cannot find a single source explaining differences and compatibility.

 

The best reference I could find is: https://diysolarforum.com/resources/eg4-6500-firmware-changelog.319/

But I do not even know if that is compatible with other inverters.

 

Specifically, for my case, I have a Kodak 7.2OG (Voltronic Axpert MAX 7.2). I want to find the best firmware for it. Currently, the display (MCU) does not show the second PV input, and it does not allow me to change any settings after 37 (I cannot even turn off the LED bar).

 

I am even willing to help curate such a list (probably as one or more GitHub repos), but am struggling to find enough information to begin.

 

Any information would be helpful.

@Coulomb

 

Also need firmware for this same inverter, hope someone can assit.  

7 hours ago, ShaunH said:

The best reference I could find is: https://diysolarforum.com/resources/eg4-6500-firmware-changelog.319/

Wow. Whoever EG4 is, they seem to have official release notes. Impressive! My next inverter might be from them, if I can afford it.

7 hours ago, ShaunH said:

Specifically, for my case, I have a Kodak 7.2OG (Voltronic Axpert MAX 7.2). I want to find the best firmware for it. Currently, the display (MCU) does not show the second PV input, and it does not allow me to change any settings after 37 (I cannot even turn off the LED bar).

The closest thing to this would be my What Axpert Firmware is That? post. But it usually just summarises an entire firmware series, with just the occasional note about a release note gleaned from a firmware update file name or the like.

I think that Voltronic used to have release notes, and all the firmwares available for download, but the arrival of the clones killed all that. I might be able to help a little later.

1 hour ago, Coulomb said:

Wow. Whoever EG4 is, they seem to have official release notes. Impressive! My next inverter might be from them, if I can afford it.

[Will Prowse](https://www.youtube.com/@WillProwse) boasts their equipment a lot. They are a more budget-friendly supplier, and I would have gone with them if shipping to South Africa didn't cost the same as my whole system.

1 hour ago, Coulomb said:

The closest thing to this would be my What Axpert Firmware is That? post.

This is an excellent post. Thank you. It definitely helps a lot.

 

If you do not mind, a few questions:

1) Do the version numbers mean anything relative to one another? I am used to semver, but, based on your post about patches, the convention is to prepend a number to the start.

2) How do you program and build the firmware? Can you build the source based solely from the `.hex`? How do you get access to the source code?

8 hours ago, ShaunH said:

1) Do the version numbers mean anything relative to one another?

A little. After version 12.34 it will usually be 12.35, or perhaps 12.40 if it's a major update. Though now that they are running very low on numbers, they don't seem to do these major updates any more. 12 in these examples is what I call the major version number, it often is common for all the firmwares for a particular model. When they get to 12.99, they'll go ti 13.00, even if major number 13 is already used for something else. 

There are already many overlaps, e.g. 71.xx is used for at least three models. Version number 71.86 is a commonly seen number for at least two vastly different firmwares.

Even though some later displays could show 3 digit major firmware numbers, they rarely use it. So far only for display firmwares for the GigaDevice chips. They will often jump libg distances in the minor numbers, like xx.02 to xx.63 (same xx). Usually but not always a larger minor number means a later firmware. 

Then there are the 9y.yy numbers, which can be anything for any model, and are supposed to be experimental. Though some machines seem to come from the factory with such firmware. 

9 hours ago, ShaunH said:

How do you program and build the firmware?

It's a slow and complex process, that Weber and I have only just this year gotten to a moderately automated system. You still have to know how the relevant part of the firmware works, and you have to know your C2000, Arm, or Freescale assembly language. 

 

9 hours ago, ShaunH said:

Can you build the source based solely from the `.hex`?

No, though one day we might come close. There will be no comments, and it will be very low level C code. But I need to write a C2000 front end for Mahindra (hope I got the name right, the open source disassembler and decompiler). 

9 hours ago, ShaunH said:

How do you get access to the source code?

We don't. Real hackers don't need source code 🤓. 

Hi, I have 2 axpert inverters 5kva 48VDC. The firmware versions is 72.7 and the other is 52.3. Is there any compatible firmware with both these versions for me to parallel these 2 inverters? My supplier does not do software, so I don't know where to get firmware or info on firmware.

On 2025/10/08 at 5:41 PM, Pappa said:

The firmware versions is 72.7 and the other is 52.3.

If these are the original versions, with the small non-removable displays, congratulations on having some of the oldest Axperts still running! I think that my 9 year old inverters came with 72.70.

Both of these older models can run patched firmware version 73.00e (note: do not run factory firmware version 73.00 with no letter after it; it will eventually stop with fault code 90. This was one of the first firmwares to implement fault code 90).

https://forums.aeva.asn.au/viewtopic.php?p=70827#p70827

If you don't want patched firmware for whatever reason, I think you should be able run version 72.90, if you can still find it somewhere. I would not run 72.xx and 53.xx in parallel, even though it may let you try. Of course, you need the appropriate paralleling boards and associated cables.