Hi,

First of all, big thanks to all supporters and followers of this great forum, and special thanks to @Coulomb for his unmatched efforts and work!

I am a big fan of this forum and have been following since a couple of years. I used to have a very old inverter for the past 4 years (an unbranded Axpert EX 3000-24), but recently I wanted to upgrade directly to one of the most recent models. Furthermore, a week ago I bought a brand new Axpert VM IV TWIN from a trusted local supplier named "Marvel" which they have their own brand printed on the original Axpert with an 18 month warranty.

As a Software Engineer, I'm very obsessed with everything software including firmware. I'm currently looking to upgrade my inverter's firmware to the latest available version. I searched a lot in this forum in the past couple of days but never found a way to fetch the latest version of a firmware other than by posting current details and asking the question in a new forum thread. So, excuse me if I'm doing it the wrong way.

Attached are the photos of the inverter's sticker, U1, and U2 firmware versions. U1 (60.05) U2 (39.09)

Additionally, I believe that I do have a (stuck at 60 V) issue with my MPPT charger that I will explain right after I get a reply about the latest firmware. Then I will be asking about upgrading the firmware of the Wi-Fi Kit that comes with my inverter which is connected to DessMonitor platform (SmartESS).

Kindly,
Tarek Y.

4 hours ago, Tarek Y. said:

Attached are the photos of the inverter sticker,

It's good that you attached the photos, because...

Quote

U1 and U2 firmware versions. U1 (60.06) U2 (39.09)

I think you meant 60.05. I don't have any VM IV firmware, but I do have a VM III firmware dated 26/May/2023, and no later versions. So I'd say you have the latest version that is readily available, and that VM III and VM IV do indeed come with the same main firmware, just different display software.

Alas, I have no 39.xx display firmware at all.

4 hours ago, Tarek Y. said:

Additionally, I believe that I do have a (stuck at 60 V) issue with my MPPT charger

Huh, a new low, so to speak. It should be pretty easy to change that minimum to say 200 V.

Edit: But it will only be useful to you if you're prepared to reflash with patched main firmware that was written for the Axpert VM III Twin (1500/4000/6000 W).

Edited August 12, 20232 yr by Coulomb

41 minutes ago, Coulomb said:

I think you meant 60.05

Exactly! My bad I didn't type it correctly from my photo of the display. I corrected it in my original post for future readers.

44 minutes ago, Coulomb said:

but I do have a VM III firmware dated 26/May/2023, and no later versions. So I'd say you have the latest version that is readily available

This is great news for me! My Inverter's serial number shows that it was manufactured in April 2023, which most probably means that my supplier upgraded the firmware before selling the unit! I'm impressed!

48 minutes ago, Coulomb said:

and that VM III and VM IV do indeed come with the same main firmware, just different display software.

I came to the same conclusion too after reading many topics here in the past couple of days.

49 minutes ago, Coulomb said:

Huh, a new low, so to speak. It should be pretty easy to change that minimum to say 200 V.

I will provide you with much more information with graphs tonight, so you can decide whether it is a normal behavior or a glitch. I'm totally new to MPPT chargers and I'm not 100% sure that the behavior I'm witnessing is abnormal! And yeah, I will have to reflash with a patched firmware to fix the issue, as I expect it will be much worse in the winter.

 

Thank you very much for your prompt and quick response.

Best Regards,
Tarek Y.

Hi again @Coulomb,

I apologize for not following up in a timely manner due to some normal life issues which can always get you too busy and change priorities! Now, let's go straight back to my PV stuck at 60 V problem..

Observations:

1- At dawn, during the very first 1-3 minutes exactly of PV input, the inverter beeps several times repeatedly indicating that it is gaining and losing PV with every beep knowing that "Beeps While Primary Source Interrupt" setting is enabled. In more details, when PV input reaches 60 V for the first time it beeps, then 0-3 seconds later it beeps again and PV input falls right back to 0 V, then gradually raising again to 60 V and beeps again.

2- After several alerts, inverter stops beeping and PV voltage never goes below 60 V again with input current always being 0.1 A while PV voltage starts raising up, this lasts approximately for less than 2 hours with no PV power input. Lastly, PV input current starts raising above 0.1 A which starts giving PV power finally.

3- Before dusk, PV goes back to the same state at dawn showing the same issues in reverse order. In more details, around 60 V, input current 0.1 A, 0 W input power for about another 1.5 hours

4- At dusk, inverter beeps several times repeatedly indicating that it is gaining and losing PV with every beep for another 1-3 minutes, until it completely stops.

My PV Setup:

3 x LG MonoX Plus LG445S2W-U6 wired in series

Specifications sheet attached
PV panels usually reach 123 V at peak and a max power of around 1090 W, which is the best possible outcome in summer (near STC electrical properties)

Reference:

You will also find attached my inverter log (formatted) for the entire day of September 10, 2023.

----------------------------------------

A. Would you please confirm that this is a stuck at 60 V issue?
B. Regarding your already patched VM III TWIN firmware for stuck at 90/120 V bugs, could it solve or ease my issue?
B. Would you please make a patch for this firmware bug?

 

Best Regards,
Tarek Y.

LG MonoX Plus S2W-U6.pdf Inverter Log 2023-09-10.xlsx

Edited September 24, 20232 yr by Tarek Y.
Some re-formatting

Hi

I think First of all You should go with more panels to shorten both ends of the PV graph with 60V stuck.

123V is far from inverters nominal voltage. 

 

Best

 

I think First of all You should go with more panels to shorten both ends of the PV graph with 60V stuck.

123V is far from inverters nominal voltage. 

Thank you for your suggestion, you're right indeed!

I might double my PV panels capacity in a year or so, but for the meantime, I think a firmware patch might ease the issue. Budget is too low right now.

Edited September 11, 20232 yr by Tarek Y.

These are patched firmwares version 260.06 and 560.06, based on factory firmware version 60.06 for the Axpert VM III Twin 6kW, 4kW, and 1.5kW, and the Axpert VM IV Twin 6kW, 4kW and 1.5kW. These patches implement most of Georg's MPPT "stuck at 90V" patches (here it would be "stuck at 60 V"), and fix the premature float bug. The only parts not applied are for the forward current constant, which doesn't seem to be changed based on solar voltage in any VM firmwares. The version number should display in full when using monitoring software, but will still show as 60.06 on the front panel display. Do not use with any other models, not even older VM III and VM IV models with power ratings like 5 kW or 3 kW, or non-twin models. Use at your own risk.

In the reflash tool, you may have to navigate to the folder with the patched files the first time it is run. Choose the hex file with the voltage you want, 200V or 150V. Use 200 V unless your PV panels are particularly low voltage. You can also of course choose the original factory firmware.

Firmware upload instructions.

NOTE: If you have particularly low panel voltage, you likely need a lower voltage version of the patch; see this post below.

 

EDIT: I HAVE DELETED THIS PATCHED FIRMWARE, AS IT WOULD NEVER REACH FLOAT STAGE. PLEASE USE patched firmware versions x60.10 instead, which is newer and fixes this issue. My apologies to any that this has affected.

Edited January 18, 20251 yr by Coulomb
Added note re low panel voltage.

Dear @Coulomb,

I have just tried firmware 560.06 but did not get any PV power input (0.1 A, 0 W) although PV voltage was totally normal according to this sunny day. Same happened with firmware 260.06. So I reverted back to firmware 60.06 which restored normal functionality for my VM IV-4000 TWIN. Note: my original firmware was 60.05, so at the end I benefited from a new firmware with a minor version increment of 1 😜

I will send you in a bit some screenshots for more details on all my firmware testing this morning.

------------------------------

Anyhow, for everyone's reference, attached in a later post in this topic some historical graphs for my PV (Current/Power/Voltage) with my (stuck at 60 V) issue. Graphs data are collected every 5 minutes.
1- November 19th (Raining All Day) got almost no PV power all day long.
2- November 22nd (Mostly Sunny) as always, no PV input for almost the first hour and almost the last 1.5 hours
3- November 23rd (Sunny) no PV input for the first 50 minutes and almost the last 1.5 hours

I will be posting new graphs for comparison purposes after we get the firmware totally working on my inverter!

Edited November 24, 20232 yr by Tarek Y.
Moved screenshots to a newer post in the same topic

Can you post the PV voltage (or PV power) along with the PV current, please?

Also, is that really panel current, or output from the "solar charger" translated to battery voltage? It looks like genuine panel current.

PreviouslyTarek said:

Quote

PV panels usually reach 123 V 

So I do not know if mppt start at 150V ???

 

Thanks Coulomb for the firmware. 

Now I can buy  this inverter.

35 minutes ago, bratpit said:

PreviouslyTarek said:

So I do not know if mppt start at 150V ???

 

Thanks Coulomb for the firmware. 

Now I can buy  this inverter.

Please precisely review the specifications of the normal and the TWIN models of VM IV
You can find the answer in there. TWIN models start at 60 V MPPT

Oh I know.

I mean that You got 123V in panels but Coulomb up starting MPPT voltage  to 150-200V.

So I think start MPPT will never happen in this situation.

Am I wrong?

2 hours ago, Coulomb said:

Can you post the PV voltage (or PV power) along with the PV current, please?

Also, is that really panel current, or output from the "solar charger" translated to battery voltage? It looks like genuine panel current.

Sure, all of the needed graphs for the same three days are attached here now. Actually I took new screenshots for PV1 Current so that all the graphs overlap over each other when explored sequentially in a photo viewer.

2023-11-19 PV1 Current
2023-11-19 PV1 Power
2023-11-19 PV1 Voltage

2023-11-22 PV1 Current
2023-11-22 PV1 Power
2023-11-22 PV1 Voltage

2023-11-23 PV1 Current
2023-11-23 PV1 Power
2023-11-23 PV1 Voltage

It is genuine panel current as you can figure out by yourself from the other graphs now.

Data Graphs.zip

10 minutes ago, bratpit said:

Oh I know.

I mean that You got 123V in panels but Coulomb up starting MPPT voltage  to 150-200V.

So I think start MPPT will never happen in this situation.

Am I wrong?

Oh sorry, I just got your idea. Yes you are right. I hope Coulomb already got this correctly!

15 hours ago, Tarek Y. said:

I have just tried firmware 560.06 but did not get any PV power input (0.1 A, 0 W) although PV voltage was totally normal according to this sunny day.

Wow. You must have very few panels; I'm amazed that it starts at all. As a point of interest, how many panels do you have?

So I think you need a 100 V patch, possibly even a 90 V patch. I'll start with the 100 V patch next post; patched firmware version 160.06. It may well be that when the target voltage is above what the panels are when open circuit, the MPPT doesn't bother trying to pull any current, as that would just make the voltage even lower.

These are patched firmwares version 260.06, 560.06, and 160.06, based on factory firmware version 60.06 for the Axpert VM III Twin 6kW, 4kW, and 1.5kW, and the Axpert VM IV Twin 6kW, 4kW and 1.5kW. These patches implement most of Georg's MPPT "stuck at 90V" patches (here it would be "stuck at 60 V"), and fix the premature float bug. The only parts not applied are for the forward current constant, which doesn't seem to be changed based on solar voltage in any VM firmwares. The version number should display in full when using monitoring software, but will still show as 60.06 on the front panel display. Do not use with any other models, not even older VM III and VM IV models with power ratings like 5 kW or 3 kW, or non-twin models. Use at your own risk.

In the reflash tool, you may have to navigate to the folder with the patched files the first time it is run. Choose the hex file with the voltage you want, 200V, 150V or 100V. Use 200 V if your PV panels are nearly always well above 200 V. Otherwise, use the 150 V version if your panels are almost always above 150 V. Use the 100 V version if your panels are particularly low in voltage.

You can also of course choose the original factory firmware.

Firmware upload instructions.

Edit Jan 2025: THIS PATCHED FIRMWARE HAD A BAD FIX FOR THE PREMATURE FLOAT BUG. Please use patched firmware versions x60.10 instead.

 

 

Edited January 18, 20251 yr by Coulomb

5 minutes ago, Coulomb said:

Wow. You must have very few panels; I'm amazed that it starts at all. As a point of interest, how many panels do you have?

Already mentioned in my first post describing the PV stuck issue in details..

On 2023/09/11 at 2:32 PM, Tarek Y. said:

My PV Setup:

3 x LG MonoX Plus LG445S2W-U6 wired in series

Specifications sheet attached
PV panels usually reach 123 V at peak and a max power of around 1090 W, which is the best possible outcome in summer (near STC electrical properties)

 

Thanks. My bad; I totally failed to notice that. Sigh. Let's hope that the 100 V patch fixes the problem, or at least makes it much better.

I will try my best to test the latest patch within the next 24 hours. Errands are piling up...

Today I tested the patch for a whole day. The weather today was heavily clouded, rainy at times, and sunny at other times for short periods of time.

Attached are the data graphs for today as the first test day for the 100V patch. I will provide more graphs later for the following days up until we have a sunny day to make the final test and assess whether my setup needs a 90V patch or not. 

2023-11-26 PV1 Current
2023-11-26 PV1 Power
2023-11-26 PV1 Voltage

Huge thanks to @Coulomb for making all of this possible and happening!

Data Graphs (100V Patch) Test 1.zip

It's looking pretty good to me for a heavily clouded day. Though:

On 2023/11/27 at 1:39 AM, Tarek Y. said:

sunny at other times for short periods of time

I didn't see more than 0.5 kW, would those periods of sun maybe not made it into the graphs because of the 15 minute (?) sampling?

Though I suppose with just 3 445 W panels, you'd only see about 1 kilowatt max near the middle of the day?

 

 

On 2023/11/28 at 9:46 AM, Coulomb said:

I didn't see more than 0.5 kW

I am currently in a very low energy consumption period of time (temporarily), so my batteries are never empty. Even in sunny days from previous days, I won't get more than this amount of energy. Additionally, the inverter is getting 30+ minutes of AC input just 2 hours before PV starts charging, which brings them to the constant voltage charging stage.

 

On 2023/11/28 at 9:46 AM, Coulomb said:

because of the 15 minute (?) sampling?

The sampling interval at DessMonitor free service is 5 minutes. I have previously mentioned the sampling interval..

On 2023/11/24 at 12:30 PM, Tarek Y. said:

Graphs data are collected every 5 minutes.

 

On 2023/11/28 at 9:46 AM, Coulomb said:

you'd only see about 1 kilowatt max near the middle of the day

Exactly! I also mentioned this in my issue description..

On 2023/09/11 at 2:32 PM, Tarek Y. said:

PV panels usually reach 123 V at peak and a max power of around 1090 W, which is the best possible outcome in summer

Edited November 29, 20232 yr by Tarek Y.

So, attached are the data graphs for PV (Current, Power, and Voltage) for the last 3 days after testing the (100V patch)..

2023-11-27: Stormy and Cloudy
2023-11-28: Mostly Cloudy
2023-11-29: Partial Clouds. Data is very intermittent because of very frequent internet outages

The last day I witnessed the least amount of time without power input while PV is present (the least stuck at 60V issue).

@Coulomb, do you think I should test a patch for 90V for even better results than Wednesday?

Data Graphs (100V Patch) Test 2.rar

10 hours ago, Tarek Y. said:

do you think I should test a patch for 90V for even better results than Wednesday?

Yes. I'm a bit concerned about the gaps in the middle of the day with very low PV current. Are they that low because it was so dark, or was it because the panels did not even reach 100 V at that time, yet could have contributed a little power?

There is also the question of whether forcing to 90 V will always be enough to kick the panels all the way up to Vmp. But if not, you can always revert to the 100 V patch.

These are patched firmwares version 260.06, 560.06, 160.06, and 960.06, all based on factory firmware version 60.06 for the Axpert VM III Twin 6kW, 4kW, and 1.5kW, and the Axpert VM IV Twin 6kW, 4kW and 1.5kW. These patches implement most of Georg's MPPT "stuck at 90V" patches (here it would be "stuck at 60 V"), and fix the premature float bug. The only parts not applied are for the forward current constant, which doesn't seem to be changed based on solar voltage in any VM firmwares. The version number should display in full when using monitoring software, but will still show as 60.06 on the front panel display. Do not use with any other models, not even older VM III and VM IV models with power ratings like 5 kW or 3 kW, or non-twin models. Use at your own risk.

In the reflash tool, you may have to navigate to the folder with the patched files the first time it is run. Choose the hex file with the voltage you want, 200V, 150V, 100V or even 90 V. Use 200 V if your PV panels are nearly always well above 200 V. Otherwise, use the 150 V version if your panels are almost always above 150 V. Use the 100 V version if your panels are particularly low in voltage. Try the 90 V version only if you have just 3 panels, the very bare minimum.

You can also of course choose the original factory firmware.

Firmware upload instructions.

dsp_x60.06_patched_200V_150V_100V_90V.zip

Edit: Having done the work to add the 90 V patch, I realised that the voltage graph for 2023-11-29 with the zero current in the middle shows decent voltage, around 135 V, near the highest for the whole day. So the lack of voltage doesn't seem to be the problem. Sigh.

But I think it will still be good to test this, and make use of a willing tester that provides good data 🙂

BTW, sorry for asking so many questions that you kindly provided the answer to in your earlier posts. I forget each person's history, and often I have to drag information out of posters to figure out what's going on. Thanks for being an exception!

Edited November 30, 20232 yr by Coulomb

I've just flashed the 90V Patch onto my inverter. The day will start in a few hours, so I will be providing first day data graphs by the evening. Hopefully it will be a sunny day with some clouds as forecasts tell.

Moreover, while on the 100V Patch last day, I tested enabling the buzzer for power source change, unfortunately, I still got so many buzzes at the beginning and end of the day. I will see if things get better on the 90V Patch.

  

16 hours ago, Coulomb said:

So the lack of voltage doesn't seem to be the problem. Sigh.

I'm glad you figured it out by yourself. I also checked again my interactive data graphs inside DessMonitor platform and it shows that there have been actual records at the time. I was afraid that the graph had too many data fillers caused by my internet outages that day.

 

16 hours ago, Coulomb said:

But I think it will still be good to test this, and make use of a willing tester that provides good data 🙂

Yep, I am more than happy to test things out. It's my please to cooperate with you!

 

16 hours ago, Coulomb said:

Thanks for being an exception!

Thank YOU for being the firmware hero! No worries mate, I appreciate your work very much. I understand how hard it is to keep track of all the details, and having to pull out information while troubleshooting.

Edited December 1, 20232 yr by Tarek Y.