Coulomb

Those capacitors seem to work hard, and often seem to fail with weird effects. I don't believe that they are 100 nF as shown on the schematic, I think that they are closer to 10μF (at least for 5kVA 48V models). So it might be worth replacing those with decent quality 50V parts, if you can find them in a suitable size. The other possibility is more gate driver parts, like the bipolar transistors.

It can't be that; as far as I know iGrid implies Infini (on-grid) and iSolar implies Axpert (off-grid). So all Infini firmwares would be G not S, but that doesn't seem to be the case.

Just use your computer's file explorer. On Windows, you single click on the file name below a file's icon and the name will highlight, and you can edit it. Just click away from the name to confirm the change. As to what name to change it to, use the same file extension (part after the final period/dot) as the infini file names have. Actually, I have both of these in my collection, and they are both called "dsp.hex" (without the quotes). So there is actually no need to rename. However, that means that the old reflash tool will be looking for dsp.hex in the same folder (directory) as the reflash tool itself (the .exe file). So make a copy of an Axpert reflash folder, rename the dsp.hex to something like dsp_axpert.hex (or simply delete it), and copy the dsp.hex from a Infini reflash folder to that new folder. Go to that new folder, and run the reflash tool from there. That should cause the Axpert reflash tool to read the infini dsp.hex file. Assuming that works, the control board is now running Infini firmware, so any later firmware updates should be done with an Infini reflash tool. Yes, use monitoring software to perform a "factory reset" of most of the parameters. Do let us know how it goes. I suspect that you may run into problems with calibration of measurements, and possibly with serial numbers, and other things related to the EEPROM contents.

Are you saying that each inverter's grid input has a residual current breaker in series with a classic breaker? Or is the classic breaker on the inverters' outputs (heading to the loads)? 16A seems marginal for an 8kW inverter, especially on the AC input, where you might have 8kW of loads plus several kilowatts of AC charging. That could explain the 16A RCDs breaking, and that might somehow cause the 63A breaker to trip. I'll grant you that this is a long shot. It might be worth replacing the bypass relays (contactors?) in one of the inverters to see if that helps. Perhaps just the neutral changeover relay, as that switches earth to the inverter's neutral output. If that is slow or arcing or stuck, it might cause current imbalances that trip the RCDs. Also check the earth and neutral wiring of the premesis carefully. Just a little neutral current carried by an earth wire somewhere will unbalance active and neutral currents and cause RCDs to trip. Edit: Also check for screws missing on the main boards near these bypass relays. The earth connection to the changeover neutral relay usually goes through a hex screw and its threaded standoff, via the metalwork to the inverter's earth terminal.

It's not "normal", but it is common on many Voltronic Axpert inverters with the high PV voltage rating, which is almost all of them these days. I have a big post about patched firnware, see the section on MPPT stuck at 90V. It tells you what patched firmwares are available for particular models. Voltronic do have several firmwares that do OK with this issue, but none of them seem to be "mainline" firmwares with version numbers like xx.yy where yy < 60. But it seems that Georg's original patches work best. I merely adapt his patches to many Axpert firmwares for many models. There does seem to be a way that the bug manifests towards the end of the day, though it often seems to be less noticeable there compared to mornings. As to why the bug is there at all, my guess is that these MPPT chargers run off PV power, so in the morning, it's important not to demand too much PV power, as you may "strangle" the weak PV power needed to run the charger's electronics. Power electronics running on marginal power supplies is not a good thing, so they have special code to prevent this. As the AI suggests, it seems over cautious the way it does this. I have to say it's somewhat flattering to have AI mentioning my forum name directly 😊. Now if we could somehow train it to point to my patched firmware post directly, that would be wonderful.

That's up to you. The fully patched firmware has a number of features. But if you happen not to use any of those, you could go to factory firmware, which is now much more recent. Without release notes, we don't know how significant the factory firmware changes are. Main firmware is usually called DSP. I can't recall if this is important or not, but doing it in that order probably doesn't hurt. Edit: Sorry for the late reply.

It looks identical perhaps. But is the transformer turns ratio the same? Do the various sensors use the exact same scale? Does the EEPROM layout match enough to be useful? Is the DSP chip the same? I suspect that the Infinis might use floating point instructions, meaning that a '2809 DSP would just crash. It's possible that it might work, but I think it would be very risky, and I don't recommend it. Certainly it would require using an Axpert reflash tool with an Infini hex file, and you may need to rename the hex file. To go back again, assuming that it doesn't immediately brick the inverter, you'd have to di the opposite; use an Infini reflash tool with a suitable Axpert hex file again renaming as needed. Immediately after each reflash, you would need to run a command to reset the settings to factory. Even then, most if not all of the calibrations could be wrong, so many of the measurements could be inaccurate. Finally, in most jurustrictions, running the inverter would be illegal, as the inverter would be capable of exporting non-trivial power to the grid, and the model would not be type approved and registered (I think). There are just so many ways that this could go wrong.

Err, won't you need to add a beefy relay, its associated coil driver, and some hefty cables? Did you mean 71.03? Though that will be for 4.0 kW of rated output, not 4.2 kW. 71.03 is available here.

Assuming that this is the 145 V max PV model, 5kW, then the latest factory main firmware is 72.05. The latest factory display firmware is 02.89 (again, only the 145 V max PV model). Firmware upload instructions for models with a removable display. The latest fully patched firmware pair is 72.00a and 02.83a.

That's the U3 version. I need the U1 version, i.e. the one starting with U1 and then 4 more digits. I assume you mean it's a file whose name ends with ".bin" and is binary (i.e. if you type its contents, it's gibberish). Are you able to use that file to reflash your firmware? Presumably it came with other files, including instructions.

I create many patches, for a wide variety of Voltronic inverter models. The most recent set is x78.10, which has the "stuck at 90V" issue worked around, and optionally also or only the 100 A charge current limit threshold changed from 360 V to 450 V. But it won't work for your inverters, which have the '2809 processor, and 78.10 is for the '28066 processor. The latest patched x64.xx firmware set is indeed x64.62, available here with instructions. Unfortunately, 64.62 (on which the x64.62 patched versions are based) is a month older than the 64.09 that you have now. There is also factory (not patched) firmware version 64.69, which is 2 months more recent than 64.09, but I have not patched it at present. Also unfortunately, x64.62 does not patch the 100 A charge limit threshold. This is a fairly recently discovered issue, so there are only a few patched firmwares that implement it. I don't know the JK BMSs. If they talk a protocol that the Voltronic inverters support (e.g. Pylontech etc), then you could use that battery type with the inverters. They would also have to talk to each other, to get the maximum charge current correct for two paralleled strings of cells. Otherwise, you'll have to choose the USEr battery type, and forgo the ability to protect individual cells going over- or under-voltage. If there is enough call for it, I could patch 64.69 the same as I did 78.10. That would be the latest firmware available in the 64.xx series, and would optionally change the 100A current limit PV voltage threshold.

This is patched firmware version x78.10, based on factory firmware version 78.10 for the Axpert Max E 11kW '28066 Twin. Do not use with any other model. The original hex file is dated 26/Jun/2025. This firmware works around the "stuck at 90 V" problem by changing the current threshold from 0.50 A to 0.10 A. It also fixes the premature float bug, and changes the reported version number to x78.10. The removable display will continue to show version U1 78 10. This firmware also optionally changes the PV voltage at which the charge current is limited to 100 A from 360 V to 450 V. In each case, the version with this change has the higher first digit. The version without this change has the lower first digit. Use at your own risk; I cannot test this firmware as I do not own an Axpert Max. It has been "sanity checked" by disassembling the firmware and confirming that the intended changes are present. Firmware upload instructions: https://forums.aeva.asn.au/viewtopic.php?p=87767#p87767 Choose the minimum MPPT voltage that is higher than your working panel voltage even in poor light. dsp_978.10_patched.inv: Minimum MPPT voltage 90V. For very low panel voltage. The 100A charge limit patch IS present. dsp_878.10_patched.inv: Minimum MPPT voltage 90V. For very low panel voltage. The 100A charge limit patch is NOT present. dsp_578.10_patched.inv: Minimum MPPT voltage 150V. The 100A charge limit patch IS present. dsp_178.10_patched.inv: Minimum MPPT voltage 150V. The 100A charge limit patch is NOT present. dsp_378.10_patched.inv: Minimum MPPT voltage 200V. The 100A charge limit patch IS present. dsp_278.10_patched.inv: Minimum MPPT voltage 200V. The 100A charge limit patch is NOT present. dsp x78.10 Max E 11kW '28066 Twin patched.zip

I forgot to mention that this could be because you are not using a USB to RS-232 converter cable, attaching to the D9 to RJ-45 cable that should come with the inverter (but some clones may not supply it). You can make your own; pinout here (don't connect +12V, just the other three wires). The communications port is NOT an ethernet port, even though it uses the same connector. See Firmware Upload Instructions. You could also connect via USB, or attempt to use a USB stick via a USB OTG cable. All in the above instructions.

I need to know the main (U1) firmware version. You can still read this even in fault mode, either from the front panel, or via monitoring software.

Agreed. As far as I know, no genuine Voltronic firmware outputs anything other than 000dd.dd where all 4 of the ds are digits. So this is custom, or more likely patched firmware (patched by the clone manufacturer, not anyone on this forum). So it's really hard to guess what Voltronic model they might have copied. Because it's PF0.8 (rated power is 0.8 x rated VA), it's likely not a recent VM II model. It could be using an 8-bit processor, or it could use a '28062 DSP. So sorry, I can't be of much help.

See If You Think Your Inverter is Bricked. Basically, you need to have faith, try many times, and perhaps vary the timing.

You are more likely to get responses on this forum when posting in English. Unfortunately, MKS III firmwares are rare for some reason, and I have no 63.xx MKS III firmwares at all. Your only hope is to get a firmware update from your inverter supplier, unfortunately. Edit: BTW, the MKS III models are very different from the VM III and VM IV models discussed in this thread. The firmware is literally twice as large for the MKS models, for example.

BritishRacingGreen's schematic is from an Axpert Max, but I suspect as per the above, this circuit hasn't changed much over the years. His schematic is easier to follow too:

? The AEVA repair page documents two solutions: replacement of the battery-side electrolytic capacitors, and replacement of the SG3525 chip itself. I note that the Axperts can be cranky about the brand of SG3525; best to replace with the same brand as existing, where possible. That logic sounds good to me. The buck stage only actively bucks when charging the battery (in these models, from either solar or utility). Good luck, and let us know how it goes.

Yes, 78.10 is for the Axpert Max E 11kW '28066 Twin. It has the QDOP command, so it should be able to have settings based on SoC% (from the display at least, as long as the display firmware is recent enough). As usual for "production" firmwares (minor version number < 60), it does not have the "presumed good" MPPT voltage control algorithm.

You might be running into the issue where when sending commands to the USB port, you (sometimes?) have to send a maximum of 8 characters in a single command. So commands with more than 5 characters (so more than 8 when adding the carriage return and two CRC characters) should be split into two write commands one after the other. This might be fixed in later Python libraries.

Yes, that's the only 7.2kW patched firmware in the x45.xx series. Unfortunately, it's a bit old now, so it's a fixed 120 V minimum MPPT voltage, which may not be ideal. There is no need to update the display firmware for this issue.

This is a clone, so it may not be possible to update the firmware at all. What is the present main (U1) firmware version? Unfortunately, the sticker doesn't tell everything needed about the inverter, e.g. the chipset used.

Fan control doesn't seem to be Voltronics' strength. I have no idea which Max 11kW '28066 non-Twin firmware has the best fan control, but the latest is 73.83, see below. There is also 73.78, a little older, available here with original (unpatched) and various patched versions for mitigating the "PV stuck at 90 V" issue. This is main (U1) factory firmware version 73.83 for the Axpert Max 11kW '28066 non-Twin. Do not use with any other model or version. Use at your own risk. The hex file is dated 29/May/2024. Firmware upload instructions for models with a removable display. This firmware does not process the QDOP command, so even with suitably recent display firmware, it will not support SoC% for settings 12,13, and 29 when connected to a suitable battery's BMS. DSP_73.83-20250606T033303Z-1-001.zip

Ah. My experience is with models with no filter, sorry.