Coulomb

That would be ideal, especially if this was a specially good firmware. However, it seems to be dated 2023-5-31, which means that four firmwares are available that have later time stamps. So unless it turns out that this one has something that the others don't, then it's not a problem. @esmail-kassir,thanks for that .zip. I assume that's not how you received it from your supplier; it has a link to the AEVA website for the upload instructions. I assume that these have not overtaken the official upload instructions!

It's common to notice the lights flickering slightly as large loads come on or off. Inverters run from batteries have outputs that are nowhere near as stiff as the utility grid. Some lights are more prone to flicker, e.g. the now-ubiquitous LED lights. Capacitors do deteriorate with time and heat, and the capacitors provided in typical inverters are often not great. I recommend replacing some capacitors even when the inverter is new, but few owners can realistically do this. The main DC bus capacitors seem to be pretty reasonable, and I rarely hear of the need to replace these. They are probably not making the flicker worse, as far as I know. Though the flicker I'm talking about is very momentary, lasting less than a tenth of a second, and I would not really characterise that as a "dip". You can't really tell if the light momentarily were brighter or dimmer, it's that short. If you are noticing the lights significantly dimming for more than a tenth of a second, then you may indeed have capacitor problems.

Ah! It's an AXVM2, that's why I didn't recognise the model. That looks like a Voltronic manual. So it's probably an Axpert VM II. That was the first model to get the high PV voltage solar charge controller, back in about 2015 or so. Voltronic seem to have refreshed it as a VM II Premium recently, but those power levels look like they're not recent models. Voltronic don't seem to make any 12 V models any more, for example. "2.5K" is however a strange power rating. It's possible that it's a clone, with slightly exaggerated rated apparent power. So that could be a 3.0 kVA model, with a maximum power output of 2.4 kW. Those "PF0.8" models were known by their rated real power output, not their apparent power output. For example, mine is called a PIP-4048; the 48 is the nominal battery voltage, and the 40 represents 4.0 kW rated power. It's rated at 5.0 kVA. So any older protocol manual should do; there are several in the files section of this forum. Just avoid the Infini protocols with the commands starting with the up-arrow ('^') character.

Some are rebranded Voltronics, others are cheap clones. The clones are of unknown quality. My guess is that it is based on the Axpert VM II Premium model, though that is rated for 5.6 kW, not 6.2 kW. Sometimes Voltronic do make a special model for suitably paying customers (i.e. resellers), that has an extra 200 W of rated power. But this is an extra 600 W, just over 10%. My guess is that this is a cheap clone, and they inflate the rated power by 10% without making any changes to the design. The 6.2 kW of rated power may be a total lie, or they may have tweaked the stolen firmware to output the extra power, whether the hardware can safely handle it or not. But Voltronic are known to be lazy about listing all their models on their web page, so there could be a legitimate 6.2 kW Voltronic model. EASun are an interesting brand. Some of their products, especially the more recent ones, do seem to be legitimate rebranded Voltronic models, sometimes with custom metalwork. But EASun started off being a clone maker, so this might be old stock of a clone model, or it might be that EASun are still selling their clones (or work-alikes) in parallel with genuine Voltronic models. It's all such a mess. Almost (?) all the genuine Axpert models with the high maximum PV voltage (450 or 500 V) have this ability, though probably only when the output source priority is set to SUB. It depends on the battery, and/or the battery's BMS (if any). Typically, the BMS will tolerate the overload for a few seconds, then use its internal MOSFETs to disconnect the battery from the inverter. How safe this is is unknown to me. Obviously, if the BMS disconnects, and the inverter has no other power source, then it will shut down and drop all loads. Some models can in some circumstances operate with solar input and no battery or AC-in. They could indeed be made in the same factory. Whether that is the Voltronic factory or not isn't clear. A photo of the sticker on the side could help determine if it's a clone, but of course you usually don't get that before you buy. Yes, the SOL output source priority is for keeping the battery ready for load shedding or the like. At sunset, the grid powers the loads, if present. People are often tempted to use it, because at first glance it seems to imply "use solar as much as possible". UTI is really for if you are running from a generator. In that case, you want to use the utility (really the generator) any time it's present, since it wastes petrol to lightly load the generator. Or if the solar and battery is there literally only as a backup. In normal household use, you would use SUB for blending, or SBU if you wanted to make use of stored battery energy.

In the morning, as soon as the current is significant, the voltage has shot up. So that's not a firmware problem. However, at about 5:30pm, the voltage collapses to around 90 V well before the current has gone to near-zero. The current, when the solar charger is operating, is fairly proportional to solar insolation (light intensity), so you would get higher power from then till sundown with better firmware. What main firmware is this?

DC clamp meters use Hall Effect devices, which are notorious for drift. Did you zero the reading with the clamp near but not around the cable, then make a reading immediately after clamping? My apologies if this is all second nature to you. The Axperts always sync to the AC-in if present and within specification. I would expect the Musts to behave similarly. With Axperts, the APL versus UPS setting (AC input range) determines two things: the tolerance for AC-in voltage (APL is more tolerant), and whether the SCR board is used to speed up the AC-in to AC-out relays (only happens in UPS mode, as far as I know). Power draw in UPS and APL modes should be very similar; the SCR board should not draw significantly different power between the two settings.

Heh. I read the firmware. Texas Instruments C2000 DSP assembly language code. Interesting. I guess it's because it's not documented anywhere, apart from some old pages of mine, where I state that the output is model specific. I have disassemblies of over 100 Axpert fimwares. Yikes. But it may be possible to change settings such that line loss isn't considered a fault. Maybe it's just a warning, but I think that the QFS command reports some warnings. Perhaps experiment with setting 22, "Beeps while primary source is interrupted". It may be that turning off the beeps also turns off the warning. The protocols and their manuals are a mess. The one you have is probably one of the best for your model. I note that 60.xx firmwares don't support the PBATCD command. The 2 A utility charging should be a result of a suitable Charge Source Priority setting (setting 16), and the maximum utility charge current (setting 11), which can be set to 2 A. What exactly do you mean by "the BMS command"? If you mean PBATCD, that's not it. There are many undocumented commands relating to BMS. I can confirm that the VM3.hex you posted is from a 60.76 firmware update file. Can you attach the complete firmware update file, or at least post what the date stamp on the VM3.hex file is within that update file, please? It would be good to know how recent that firmware is. They are not necessarily in consecutive order past yy.60 these days.

A Google search indicates that this LED means "earth is used as neutral" or "earth is connected to neutral". This makes little sense to me, if the earth is provided by the combined earth-neutral cable from the transformer. This video may be relevant; I can't understand the language used, nor the subtitles. https://www.youtube.com/watch?v=-WCdFSHELJQ It's a different brand of inverter, but you may get the gist of what it's about.

The result is "(000001000...000" in ascii. All command responses start with an open parenthesis '(' or 0x28. The sixth digit is a 1, all other digits are zero. With your model, it seems that the sixth digit indicates "line loss status". * Is the AC input off? * Could the mains have dropped out overnight? * Could the mains voltage and/or frequency have gone out of spec? * What is your AC input range setting? (Usually APL or UPS). APL is less strict, though it may cause slightly longer change-over from battery mode to utility powering the loads (possibly with the help of battery and/or solar with SUB output priority).

I don't recall seeing anything about LIB or LIC protocols. I note that when using LIB or LIC protocols, the label for some settings on the VM IV display can be any three letters taken from RAM; I haven't figured out what sets those letters yet. So these may be in some sense "generic" protocols, whatever that means in practice. There is this older FelicitySolar document; it doesn't say anything about LIB or LIC: Felicitysolar BMS Communication Protocol RS485 20210608.pdf

That may or may not be a Voltronic Infini model. I don't know them well, but I do collect some of the firmwares. What are the present firmware versions?

They are the same thing, made in the same factory, just with different branding. Clones and workalikes however are different; they are made by other manufacturers, often use Voltronic firmware illegally (sometimes resulting in a fault code that stops operation after some weeks), and are of dubious and unknown quality. Telling a clone from a genuine model can be difficult. For RCT and Kodak specifically, these are almost certainly genuine, though you never know if one day these resellers might decide to go with a cheaper clone that appears to be good value (on the surface). See Do I Own a Clone? for clues.

I know nothing about the Powmr / Must models, except that they started as Voltronic clones but now have their own firmware. The usual situation with Axperts is that they will report 300 VA AC input with no load, but zero watts. The 300 VA is the imaginary power consumed by the smoothing capacitor. I suppose the inverter's reporting may be swapped or confusing. In the Axperts, the same load voltage and current measurements are used to calculate the load actual power and apparent power, using proper Root Mean Squared instantaneous power averaged over a complete 50 or 60 Hz cycle for the real power. There are no potentiometers inside; there are digital equivalents (scaling values stored in EEPROM). It's sometimes possible to adjust those values, but Voltronic hides them all. Only the battery voltage is moderately easy to adjust. With Must / Powmr, I have no idea how to calibrate even the battery voltage.

Perhaps your location uses a combined protective earth and neutral system? It's unusual, but it exists. I can't imagine what that means, especially as you claim that there is no earth. Can you post a photo of this light, please?

He has said that he can get at least 10 A from each string. So he must have two strings in parallel, each with many panels in series.

Yes, it's quite possible that the PV current is limited to a particular value. Alas, the web page and user manual (for the VM IV that I checked) doesn't say what this limit is. Often, the 500 V max PV voltage models are "nominally" 350 V; 6000 W / 350 V = 17.1 A. If true, that means that whenever your Vmp is below 350 V, you won't be getting full power from the solar charge controller. Whenever your Vmp is over 350 V, the solar power should clip to 6000 W.

Good point. This could be clouding the results, so to speak. Unfortunately, solar condition don't behave in an ideal way for making scientific comparisons. I guess we'll just have to wait for more results, possibly from more users, to average out the changes due to solar conditions.

All the lithium battery BMS comms code is in the "display" firmware, really the display and comms firmware. It should not matter what main (U1, 60.xx) firmware you are running, as far as what battery types you are allowed to choose from. Though if you are using Watchpower or another monitoring program, that might have some interaction as well; I'm quite hazy on how that works. I thought that perhaps the Put Battery Type (PBT) command might NAK the arguments that it doesn't support, but no, it seems to accept all possible arguments.

There is really only QFAULT and QFS, and frustratingly I can't find official documentation on either. Some unofficial guidance: https://forums.aeva.asn.au/viewtopic.php?p=71161#p71161 (Him again!) https://powerforum.co.za/topic/4721-axpert-mks-ii-5kw-error-08/?do=findComment&comment=73822 These really only return the conditions the inverter found itself in when the most recent fault was recorded. That's because that's all that the inverter stores. It's not like there is a hard disk in there to store historic data. Edit: However, this should hopefully be good enough to find the fault code and a few data points from any fault code that happens in the middle of the night, as long as it's not overwritten by some other fault code.

Yes, Identical. So it's quite surprising to see differences in results. Unless there is other relevant code that I'm not aware of. Edit: It will be really great to one day finally nail what the best MPPT logic is.

The 60.89 in this post is correct; it should report as 60.89: https://powerforum.co.za/topic/19010-voltronic-axpert-vm-iii-twin-4kw/?do=findComment&comment=192984 Edit: The one in Tarek's combined post is also correct: https://powerforum.co.za/topic/29708-axpert-firmware-collection-for-vm-iii-and-vm-iv-twin-models-only/?do=findComment&comment=204421

The code associated with this functionality is quite complex. I've checked what I believe is the relevant display firmware versions 39.17 and 39.26, and I see no significant differences. Likewise, I see no differences between main firmware version 60.06 (the closest I have to 60.07) and 60.87 (the latest 60.xx firmware that I have, later than 60.95), and again find no significant differences. So it doesn't look like a firmware update will solve it, unless there is a difference in code that I haven't looked at yet. There tests for the second output's cutoff voltage command's parameter, and against the CV voltage setting, the main low DC cutoff voltage. Presumably it should not be higher than the CV voltage setting, and should not be lower than the main battery cut-off setting. 45 V is quite a low voltage, even for a 15S LFP battery.

Now presumably obsoleted by 72.74. This is factory firmware version 72.74 for the Axpert Max E 8 kW '28066 non-Twin. Hex file is dated 2024-3-05. Do not use with any other model. This does NOT have the presumed "good" solar charge control logic that would fix the "stuck at 90 V" issue. Use at your own risk. Firmware upload instructions for models with a removable display. MAX_8K DSP_72.74.7z

That firmware seems to have vanished, and this firmware seems to be the only Max E 8 kW '2809 non-Twin firmware with the "good" solar charge logic, so I'll post the update file here. This is factory firmware version 46.71 for the Axpert Max E 8 kW '2809 non-Twin. Do not use with any other model. The update file has "PV voltage stuck at 90v" in one of the paths, suggesting that it solves this problem. It also has "U1 90.01" in the path, but that seems to be a copy and paste error. I removed "U1 90.01" from the zip file name to reduce confusion. I was initially sceptical, but have now decided based on user reports that this problem has finally been solved. I note that later firmwares have dropped these changes. Use at your own risk. Firmware upload instructions for models with a removable display. 8K MAX - PV voltage stuck at 90v_DSP_4671-20230521T034350Z-001.zip

Before this point, everything sounds normal. Not using all the available solar power has been a common problem with Axpert firmwares. I don't know the 24 V models well, but I collect most such firmwares that I come across. What is the present main (U1) firmware version? I'd love to get a Rand for every time I've posted that question.