Tarek Yag

I totally got you since the beginning, I just negated any port mixing of any type for you. Yep, mine have two RJ45 sockets, one for COM and one for BMS.

Not at all, not even vice versa, because the RS232 port on the BMS is not yet implemented in firmware, and it even has a different plug type. Most probably, but not due to a hardware fault, it must be a firmware bug with the exact firmware version we all had J-Tagged on the BMS before shipping from the source. I, with a few other experts, have been intensively and extensively discussing related software and hardware aspects of the issue over the course of the last two weeks (started about a month ago) to find a solution, since the manufacturer is unable to understand what the bug is, or they don't want to! Despite many of us contacting and trying to contact them and give them all the needed details of the bug. Anyway, we're far into details now hoping that we will reach a resolution of all of this, or at least give the manufacturer a ready to solve bug!!!! I totally agree! It wouldn't have happened if any check or protection is in place.

@bratpit, this is the exact same thing that happened to me. I wasn't paying much attention to charging stages after both firmware upgrades (DSP and MCU), but I'm still confident that upgrading is not the reason behind the issue we're experiencing. I started paying much attention after I failed connecting my BMS (with error 61 too); because I had to carefully set manual settings for the charger, and monitor the inverter for a while to make sure charging is safe according to my battery specifications. I'm very suspicious about the BMS connection process, as this particular issue started after it, most probably! Especially there were random messages between my inverter and battery that caused BMS's LCD display go crazy and switch display tabs repetitively and randomly, and it even messed up charging settings back then (eg. it changed max charging current to 2A). Ah, I'm really tired of debugging a lot of issues here at home, my highest priority right now is to fix the BMS firmware, then I'll have to do a thorough hardware repair for my inverter before any more debugging!!!

I meant did you do any similar settings change before the float issue started in your own inverter?

Great analysis! I will try my best to give any feedback, if possible, as soon as I try DSP 84.00 with MCU 39.26. I'm having some limits in time and I can't cut off power these days at home to perform a DSP firmware update with current soaring weather temperatures (40+ degrees Celsius).

It completely depends on your battery's type and the specifications on it. There are no general settings for all, even for the same type of battery.

It does in my case, I don't know if @bratpit has the same, actually yesterday I was sitting beside my inverter and watching it. It came to my attention that it switches to float mode (on screen too) as soon as it reaches 27.2, although my battery type is "USER" and float voltage is set to 28 just like bulk voltage. This issue with ALL its symptoms started right after I unsuccessfully tried to connect my inverter to my BMS a couple of months ago (using "LIB" battery type) when I bought my brand new LFP battery. So, my guess is that it's related to some calibration error or something like that, which is out of my knowledge so far. However, I'm hoping to get it fixed as soon as I fix my BMS upgrade issue, which for my bad luck, is a global issue for some specific relatively new JK BMS units. @bratpit, could you relate to the previous timing of the issue? It happens even when charging on AC only, so it's unrelated to PV charging, or PV and AC. Your patch was working perfectly when I used it over the course of a few months, but now it shows the same issue, so it's not about a specific firmware version.

I mean did it start immediately after a firmware upgrade, maybe? Main, or display? Or it just started randomly?

I already tested all other suitable firmware, but the problem never disappeared. Are you able to determine when exactly your problem started?

I have this exact problem but with VM IV Twin 4000 which is 24 V, but it's not only on PV charging but also AC. However, it didn't start with the version you reported, it's been around for a few months and I've always believed it's a hardware fault. Whenever it starts charging, it keeps charging until it reaches float voltage, then switches to float mode, hence, current go down gradually. So, I had to set float voltage the same as bulk voltage, at least until I fix my BMS firmware bug, to make a successful connection between my BMS and inverter. Although it took too long, but my settings are safe for my own setup.

Here are more HEX File Only Packages of (DSP / Main CPU / U1) firmware for VM III TWIN and VM IV TWIN. An updated list of available packages in this thread can be found in the very first post at: https://powerforum.co.za/topic/29708-collection-of-dsp-axpert-firmware-for-vm-iii-twin-and-vm-iv-twin/ CREDITS: Original uploaders of the attached firmware files: @mhd_murad DSP version 60.95 dated 2024/01/16 Link to original package post @Nabeel Raza DSP version 84.00 dated 2024/06/09 Note: Quiet fans control logic is not available in this version + I copied this firmware's full package from the uploader's Google Drive Link to original package post USE AT YOUR OWN RISK, NO GUARANTEES WHATSOEVER! DSP Reflash Tool is always available in the very first post of this thread at: https://powerforum.co.za/topic/29708-collection-of-dsp-axpert-firmware-for-vm-iii-twin-and-vm-iv-twin/ Detailed instructions of how to update/reflash firmware of Removable and Round Display inverter models, posted by @Coulomb at: https://forums.aeva.asn.au/viewtopic.php?p=87767#p87767 If you think your inverter is bricked, there are a number of helpful tips posted by @Coulomb at: https://forums.aeva.asn.au/viewtopic.php?p=59897#p59897 Enjoy! Additionally, here is the full package for display (MCU / Secondary CPU / U2) firmware version 39.26 for VM IV TWIN only (with round display), as @Nabeel Raza uploaded it to his Google Drive, and not as an attachment in his post at: https://powerforum.co.za/topic/29708-axpert-firmware-collection-for-vm-iii-and-vm-iv-twin-models-only/page/4/#comment-207455 VM TWIN (III & IV) DSP 60.95 hex.zip VM TWIN (III & IV) DSP 84.00 hex.zip VM TWIN_84.00.7z VM IV Panel_Reflash_MCU_39.26.zip

I guess I'm a bit late for this firmware party! 😁 Is it explicitly specified that it's for VM 4 Twin? or just like all other firmware versions (model VM III Twin). Plus, a general question, is the release date hard coded into the firmware file? or it's just the file properties. Is it the same for version 70.00 too? I might reflash my inverter to the best MPPT algorithm later on. For now, I'm gonna test version 84.00 as soon as I get your answers on this post. This feature was recently introduced in the variants of 4.2kW and 6.2kW which you already know by now. I'm sure of this because it is stated explicitly in these device specifications here in my area. I might check out setting 41 after reflashing version 84.00 on my 4kW unit.

@Nabeel Raza, now this makes a lot of sense, although a picture of the inverter's sticker would have clarified a lot more. Anyway, I'm interested in testing the new display firmware you have on your inverter. Would you please share the display firmware update (39.26)?

@Nabeel Raza I have never heard of a VM IV Twin with 5600 Watts capacity, it's usually 6000 and some newer variants are coming with 6200. Would you please provide a photo of your inverter's sticker? (You can hide or blur the last 6 digits of the serial number if you want). Generally speaking, I guess this model is a clone, not an original Voltronic Axpert, because the model name you just provided is heavily modified from original Axpert model names. And of course, thanks a lot for sharing your inverter's current firmware. As for the display firmware (Secondary CPU), the only and latest we have here is 39.16 for VM IV Twin. So, apparently you just provided us with the most recent one. Waiting for @Coulomb to have a quick check at it. As for the main firmware (Main CPU), that's a totally new version range for VM IV Twin, so I guess it's dedicated for your inverter's variant. Coulomb, any thoughs here?

I just posted latest available firmware versions for you

Thanks for referencing my thread. However, it doesn't contain main firmware for the non-TWIN variant of VM IV nor display firmware, as these two firmware are different than the ones for normal non-TWIN models. Here are the latest available main and display firmware for VM IV non-TWIN variant uploaded by Coulomb: VM IV non-TWIN Main firmware: https://powerforum.co.za/topic/19607-firmware-voltronic-axpert-vm4-5600w/?do=findComment&comment=201206 VM IV non-TWIN Display firmware: https://powerforum.co.za/topic/19607-firmware-voltronic-axpert-vm4-5600w/?do=findComment&comment=201271 For an insight about these firmware versions:

You DO need help for sure. Yeah, 45 degrees is the best for mid-winter only. Though, for fixed angle installations an angle of 32-34 degrees is best in our region, and is the most used angle by professionals.

Oops, this angle is for mid winter! You really need local help!

In the Twin variants fans are always running, they don't stop at all. However, if you upgrade your inverter's main CPU firmware to one of the latest VM III Twin firmware versions you'll get much quieter fans, as Voltronic just recently introduced the fan speed logic, finally! I need to know the following: Battery Type, Bulk Charging Voltage, Float Voltage, and a screenshot from the monitoring app when your inverter is charging your battery. Do you have any experience with inverters?

I believe it's below average for this time of the year in our region. I guess it should be around 1850 W at least if there's no shading at all on your panels. What is the tilt angle your panels are installed at? The best fixed all-year-round tilt angle in our region is 32-34. And summer is not the best season for this angle. We get the highest PV input in Autumn and Spring, but the longest and most in Summer. I guess there's something wrong in your setup. Did you consult the technician who installed the panels?

Would you please provide us with a photo of your inverter's sticker? I would like to figure out at least the manufacturing date from the serial number, you can blur the last six digits if you would. As Coulomb said, You would want to have the same version available in case anything goes wrong, so you might be able to flash back to the original version at least. More info about your inverter could be very helpful for us in the future.

I apologize if I seemed like questioning your information, you definitely know much more than me as you've been in this industry for so long. Indeed, I would expect anything in the Chinese market especially with the infinite number of clones! I was just trying to comprehend everything.

So, as I promised earlier, and since I don't put considerably high loads very often during the day. I have just captured a perfect heat sink temperature reading that should give a great insight about how good is the fans speed after the fan control update for the TWIN variants. I think they're really efficient now and balanced very well in versions (60.95 and 70.00) the ones that I've tested myself which have same fan control logic. Given (approximate averages): Room Temp: 33°C Battery Voltage: 28 V Battery Charging: 80 A PV Charging Power: 1250 W AC Output Apparent Power: 650 W Surprisingly, heat sink temperature is 50°C only! And I think it's perfect for me given all these circumstances and the very high room temperature!!

I guess you're mixing power levels by mistake. I just revised my information on the official Voltronic Power website, and made sure that non-twin variants of VM III has 1.5/3/5 kW power levels (not 4 and 6), though you've got the right levels for VM IV which are (3.6/5.6 kW). Both non-twin models use firmware major number 61.xx right now. On the other hand, TWIN variants of VM III and VM IV has two power levels (4/6 kW) and both are using firmware major number 60.xx right now (before versioning started getting messed up recently for both). I believe this justifies it all. Though, I truly appreciate your hardware-wise caution!

@Coulomb, I just tried updating my VM IV DSP firmware using the MCU reflash tool and had the update file named "dsp.hex" as required by the tool. It seems like it started writing on MCU addresses as my round display went black while the DSP stayed working normally without any interruptions. So, now I believe: 1- File 'dsp.hex' must be present to enable the tool to work when clicking "Update DSP" button (so clicking it by mistake when trying to update MCU should do no harm) 2- Even if the DSP file is present, it will just brick the display without doing any real damage, because it keeps sending the MCU reflash command without actually writing to the memory (I sniffed the serial connection to see what was going on) 3- Reflashing the appropriate MCU file should get the display working again normally