16 hours ago, runtimeassertion said:

The difference is huge! I didn't fully open it, but spotted clearcoat finish at the pcb, bigger electrolytes and lots of different thingys which make it more solid.

That's great to know, thanks.

16 hours ago, runtimeassertion said:

It came with U1 60.08 U2 25.12. I decided to update it to the latest firmware found here: U1 60.95.

I wish you hadn't. The numbers yy.60 and above are not in date order; they're almost random. Fortunately, 60.95 is fairly recent (January 2024), though 60.87 is later (February 2024). 60.89 is earlier, December 2023. I don't have 60.08, but it's possibly later than 60.95 and possibly 60.87 as well.

The 60.xx firmware date order is at the start of this useful thread:

https://powerforum.co.za/topic/29708-axpert-firmware-collection-for-vm-iii-and-vm-iv-twin-models-only/

I've updated the post that the first post of that thread links to, which fortunately updates in that first post, even though I can't edit it. If that makes any sense 🤪.

On 2024/08/03 at 11:34 AM, runtimeassertion said:

Hi @Coulomb,

Thanks a lot for the reply! I tried what you advised and it works now! 

Using your bypass cable directly flashing to the inverter, I started from 56.72 and it was succeeded. Then I tried again 60.89 and 68.04 - no luck (the process was failing at the middle with read error), so I reflashed on 56.72 and then tried 60.04. And it worked! Then I tried sequentially all 60.XX and ended with 68.04 successfully.

I couldn't imaging that if bootloader was the same the order of flashing firmwares matters.

Now I finally enjoy silent fans!

Hmmm, honestly I thought that all these inverters are OEM and available from different brands( Voltronic, Axioma, QPower, LogicPower etc) and were manufactured in the same facility somewhere in mainland China (OUYAD?), but now I see that originally it was from Taiwan, but then clones were produced  

But in any event, even if it is a clone, it looks robust and reliable inside.

 

Testing now in different modes...

 

Thanks again for help!

Hi @Coulomb , @runtimeassertion. Please tell me how to make a “bypass cable directly flashing to the inverter”? I have the same problem.

You would only use a direct cable to the inverter as a last resort, if your display was totally unusable. Even then, unless it's definitely a hardware fault in the display, you are much better off trying to get the display firmware updated, and update the inverter through the restored display. 

But if you really need that cable, I have instructions here:

https://forums.aeva.asn.au/viewtopic.php?p=90225#p90225

The post following may also help. 

Hi,
Looks like I missed some posts here...

On 2024/09/02 at 6:56 AM, Coulomb said:

60.95 is fairly recent (January 2024), though 60.87 is later (February 2024). 60.89 is earlier, December 2023. I don't have 60.08, but it's possibly later than 60.95 and possibly 60.87 as well

Oh, that explains a lot! Who came up with such brilliant versioning  But, looks like 60.08 doesn't have smart fan control - that's why I decided that 60.95 is the latest! Anyway, it works fine now. Maybe I update it once some new firmware is released...

 

On 2024/09/17 at 2:40 PM, giko said:

bypass cable directly flashing to the inverter

My display module of the clone inverter was failing to flash in less than 10 seconds, due to, most likely slow optocouplers, as Coulomb assumed in the post dedicated to the bypass cable. The original inverter didn't have such issues.

Hello, also chiming in here with a setup similar to what @runtimeassertion initially had (Axpert VM III TWIN 4kW, labeled as LPW-HY-4000VA).
It seems I was luckier as I have not encountered any issues during the flash process, so I'd like to share my experience.

U1: from 56.09 to 60.10
U2: from 25.06 to 25.15
Used software that came together with the firmware.

The process was roughly the following:

1. Disconnected everything, except battery
2. Flashed U1 via USB cable
3. Connected AC input + AC load (intermediate check)
4. Disconnected AC input + AC load
5. Flashed U2 via USB-to-RS232-serial adapter
6. Disconnected everything (power off)
7. Connected everything (battery, AC input, AC load, PV input)

Do not use this as a sole guide, please refer to https://powerforum.co.za/topic/29708-collection-of-dsp-axpert-firmware-for-vm-iii-twin-and-vm-iv-twin/  instead.

The newer firmware resolved the "stuck at 60V" issue for me. It's been more than a month since the upgrade without any new issues, so it can be considered successful.
I have not checked Wi-Fi connectivity as I abandoned it in favor of USB-to-RS232-serial adapter several months ago because Wi-Fi connection had to be reconfigured with each inverter power cycle and I wanted to stop relying on 3rd party cloud services anyway.

Hope this helps someone!

As always, huge thanks to @Coulomb for enabling others to perform inverter maintenance on their own.

18 hours ago, alextechs said:

I'd like to share my experience.

U1: from 56.09 to 60.10
...

The newer firmware resolved the "stuck at 60V" issue for me. It's been more than a month since the upgrade without any new issues, so it can be considered successful.

Thanks for the report; it's invaluable!

None of the VM II/III/IV firmwares have what I had come to presume was the best MPPT logic, yet here you have proof that the issue can be solved without it.

This prompted me to re-examine my analysis of the MPPT code, and I've come across numerous errors in my analysis. Sigh.

So I have a lot of work ahead of me, but hopefully soon I'll have an idea of what's going on, so that I can patch other firmwares if necessary, or at least identify which new firmwares are likely to have fixed the issue.

My brother have VM 4 twin with

U1 5609 ->56.10

U2 3909

It safe to upgrade U2 to 25.15

?

7 hours ago, Jazdzor said:

It safe to upgrade U2 to 25.15?

No! 25.xx is for removable displays. Update to 39.27, available here.

On 2025/01/08 at 5:13 AM, alextechs said:

U1: from 56.09 to 60.10
...

The newer firmware resolved the "stuck at 60V" issue for me.

I'll just add that I now believe that this is mostly because SOME VM III firmwares come with a minimum MPPT voltage of 120V, while others come with a minimum of 60V. You updated from a 60V one to a 120V one. In some cases, perhaps many cases, this will largely solve the "stuck at 60V" problem. However, I think that it may simply transform into a "stuck at 120V" issue instead. Not as bad, but depending on your panel configuration, it may still be far from optimal. I'd love to hear from actual users' experiences.

So it looks like many VM III owners will still need patched firmware to get proper MPPT performance.