Eddie1

Regarding the voltage readings of my axpert vm III 4k twin compared to a multimeter I've took multiple readings at different times and scenarios SC 1. Ac: on batt: full chg current: 0 inv: 27.6 multimeter: 27.7 SC 2. Ac: on batt: chg in float current: 4a in 27.5 multimitere 27.7 SC 3. Ac: off batt: inv 24.7 multimeter 24.8 load: 176 va SC 5. Ac: off batt: inv 24.0/24.1 multimeter 24.1 load: 132 va SC 6. Ac: off batt: inv 24.5 multimeter 24.5 load: 250 va SC 7. Ac: on batt chg bulk current: 32a inv: 28.8 multimeter: 28.9 So it's not a constant difference. It ranges between 0 and -0.2 v from the multimeter. Also, I noticed today that when having 2.5 kva load 1.5 kva of them going to a cooker. When turning the cooker off. The voltage shoots from 28.8 to 29.5 for a second or 2 then goes back to normal Is this behavior normal? This is the first time I notice this so I'm not sure if it happened before or if it's new. I have tubular lead acid batteries. I don't think it matters with/harms lead acid batteries. But what about gel lead acid batteries or lithium batteries?

Sure thing Once I collect enough readings in different scenarios I'll post here

Now I'm sad I've noticed this too But I thought the problem was the multimeter But now that I think about it, it's clear that it's not the multimeter but the inverter There is "almost always" a 0.2v difference (inverter showing lower voltage) even without battery charging or discharging (load using solar) My old vm II 2.5k didn't have this issue. Its reading were accurate and showed any voltage change instantly. it doesn't have any delay while the vm IIII 4k twin has 1 or 2 sec delay when showing the voltage

push buttons, brand: renovo, my inverter is exactly like the picture I uploaded before still searching for it, do you recommend some shop?

my original factory firmware is dsp: 71.01 mcu: 57.09 they did send me an ftp link that contained only the files I uploaded here. I still haven't updated my firmware because the connecter on the old laptop I have, turned out to be VGA and not rs-232 🤣 since we both seem to be from that same country where did you get the rs-232 to usb cable to update the firmware? I still can't find one to update my firmware.

I'm trying to update using usb-a to micro-usb cable becuse I dont have rs-232 to usb cable but each time I connect the cable windows says it cant recognize the device, also watchpower cant detect the inverter in the guide voltronic sent me. it stated that I can update using micro usb Edit: I think I won't be able to update mcu using USB method even if it worked for dsp I'll use an old laptop with rs-232 for the update

just to make sure I understand correctly, can I update both dsp and mcu on battery only without ac connected? because ac is not stable and gets cut randomly. I emailed voltronic and they sent me the latest frimware for my inverter my inverter is renovo vm3 4k twin current fw is 71.01 and the one they sent is 71.03 as it has been stated before the first number seems to have nothing to do with fw version or date, it might be an identifer for the brand selling the inverter. if that is indeed correct, I wonder if the inverters have some differences in components for each brand because why would they send @Mohammad Jawish a frimware with v 60.10 (triple-a brand I presume?) and send me one with v 71.03 (renovo brand) do you @Coulomb think this is possible? or the components of the inverter are always the same? I have no expertise in these things but they also sent Mohammad Jawish a copy of v 84.00 which would mean the first number is not a number for a certain brand or at least that the frimwares are interchangable between brands. VM TWIN DSP_7103.7z Remote Panel_Reflash_MCU(5716).7z

I am a little bit confused This guide says I should disconnect everything and keep only battery connected, while the document provided with the update file by voltronic says I should disconnect everything but keep ac connected Also, how long does the firmware update usually take (dsp and mcu)

Is there a way to extract firmware image from the inverter? For backup reasons in case other fw were worse

Well... Seems this is a design problem I emailed voltronic This is what they responded "We would like to inform you that this inverter only could detect the battery charging current. The battery discharging current was calculated by using PV generated power and load size. Due to the detection tolerance of PV generated power and the load size, it may cause such calculated tolerance. Besides, when the output load is powered by PV+AC at the same time then the inverter also withdraw a small power from AC grid to avoid the energy feeding to AC grid. For dual output applications, the battery voltage or charging time must meet #63, 64 settings. The output will not be forced to turn on just because there is mains power. You mentioned that the second set of outputs will not be turned on before 14:00, which corresponds to the time set on the inverter. It is not the time on Wi-Fi APP. You must first confirm whether the time setting on the inverter (#95~#99) is set correctly or not?"

How did you contact them? Through email or their main website? It makes sense if each brand has different firmware version numbers. My inverter brand is renovo and I want to contact them to see if there is different firmware for my inverter

Which firmware do you recommend? I am a little bit hesitant because I didn't find any mention of main firmware 71.01 and secondary firmware 57.09 Many axpert III 4k twin seem to come with a 6x.xx version Have you tried going from 71 to 6x?

I assume this is a software issue (please tell me it is). it's been like this since the first day. my inverter supplier is Renovo (which is a well-known supplier in my region) I have asked around and some people told me that this happens to most if not all axpert vm III 4k twin inverters as you can see my pv input power is always lower than my ac output power although the inverter is in off grid mode (since the electricity here is cut most of the day) which doesn't make sense at all. also, the chart shows the battery is charging and discharging at the same time and that it's discharging more than charging which means the battery voltage should be going down. but that's not the case since the voltage is stable at 27.3 (float voltage) also the charging LED should be on constantly since the battery is fully charged but its constantly off (meaning it thinks it's neither fully charged nor is charging) when there is electricity the inverter functions normally. the LED is constantly on when its fully charged and battery charging and discharging current becomes 0A but the solar output power stays lower than the ac output power (even more than when there is no electricity) (meaning it's using the grid and not fully utilizing the available solar energy??)I have set my output priority to solar-utility-battery. this also causes problems with the twin output (ac2) if i set the charge time to 5m for example and the battery is fully charged but the voltage dips for a little bit. the inverter then charges the battery for couple of seconds and goes back to float which means the ac2 never turns on again because it doesnt charge for 5m (and it does not realize that its fully charged?). also, it does not follow the time intervals i set for it (from 8 to 17), it never turns ac2 on before 14 and stays till 0 if there is grid available. as for the fan issue (keeps running). I asked a supplier to call Renovo and they said there is no solution to this issue. but some ppl here said that it is solved by some firmware update. a lot of questions, sorry!