Br999

Thanks for your help. Yes I've seen all the different versions... I don't have too many complaints about how it works, and I don't want/can't crash it so for now I'll stick with the original firmware, but since this weekend I added 2 solar panels, I went from 2x11 in series to 2x12 on the mppt 2 input, the nominal voltage is now around 360-400 V and since then the battery charge no longer exceeds 90 amps even in full sun, whereas with 11 panels I went up to 150A without difficulty... Am I too close to the maximum (500V)? I searched but I don't understand. Thank you for the link an idea ? THANKS 11s : 12s :

I have the following problem with Axpert Max 2 11kw Twin: Sometimes the battery charge does not exceed 90A even though the setting is 150A. This poses a problem when the day is cloudy, because during clearing the charge is not maximum, so there is "lost" energy. Do you have this problem with yours? Sometimes by playing with the AC load for example by activating the water heater then turning it off or other consumer devices this clears the blockage at 90 amps This is what I did in the example below where can we find Voltronics firmware ? Any help is welcome

Hello you can try this :

I never got a response from either the manufacturer or the seller. the problem arises less since I put several strings (two) in parallel, there are more amperes so the inverter "sticks" less. otherwise since I also improve the system I use "solar assistant" and by the mqtt protocol I retrieve the current voltage data and cut if necessary. the manufacturer does not answer I also asked if there were new versions of the firmware I never got an answer

Hello, I have had an AXPERT MAX II TWIN 11Kw inverter for a few months, and I am faced with the problem of the 90V of the MPPT controller during low sunlight, which can considerably reduce solar production. I found a solution (apparently effective) simple and without modifying the inverter, to avoid this "sticking" at 90V. Maybe someone has already proposed this solution I did not look too much on the forum. I noticed that when the photovoltaic panels are disconnected from the inverter and then reconnect the inverter, this releases 90 V and the mppt resumes normal operation. My solution is to add a contactor in my case an ABB AF16ZB-40-00-22, an esp8266 D1 mini, an ACS758LCB-050B-PFF-T Current Sensor Module, a 2Mohms divider bridge and an ads1015. The contactor is used to isolate the solar panels at night to avoid any overvoltage due to a night storm (my panels are 40 meters from the inverter = large antenna for EM lightning waves). I also added a rule: if Amperes > 0.7A and Volt between 80 and 100V for more than 2 minutes = disconnection of the solar panels then 15 seconds later reconnection. The inverter goes back to 275v, in my case (2x8 panels in series/parallel for the moment) then the mppt controller resumes its normal work. (see picture) Because in cloudy weather below 1.5/2A this remained at 90v as long as the sun did not hit the panels directly or the intensity did not rise higher. With this modification it allows me to produce more than 2.5x more during low light(on my installation).

thank you for answering me and for all this information

in fact the sizzling sounds a bit like the noise an induction hob can make maybe that's normal... on the other hand I still do not understand why in the manual apparently it is clearly indicated that the solar panels must not be connected to the ground, but then what happens if an overvoltage occurs? the surge will be directed to earth by the surge arresters and what will happen? Will the inverter burn ? is there any other solution to limit surges without having to use earth?? Putting a lightning arrester just after the panels and just before the inverter seems like a good idea to you given the cable distance?

Hello everyone, I am a new user in photovoltaics and I have a problem with my Voltronics Axpert Max II 11kW, I have a question that I cannot solve regarding the wiring of this inverter. On page 8 of the manual it says: WARNING: Because this inverter is non-isolated, only three types of PV modules are acceptable: single crystalline and polycrystalline with class A-rated and CIGS modules. To avoid any malfunction, do not connect any PV modules with possible current leakage to the inverter. For example, grounded PV modules will cause current leakage to the inverter. When using CIGS modules, please be sure NO grounding. CAUTION: It's required to use PV junction box with surge protection. Otherwise, it will cause damage on inverter when lightning occurs on PV modules. I have 30 meters between the panels and the inverter, I installed a DC box at the level of the panels in which there is fuse, circuit breaker, and anti-surge module (bipolar connect to the ground), and another box near the inverter with circuit breaker and surge protection module for each MPPT input. At the beginning I did not have a box near the panels (only near the inverter), but recently I installed the DC box near the panels, and the inverter sizzles (electronic noise) more than before (even at night). It is noted that the panels must be isolated from the ground, but the principle of a surge protector is to send the surge to the ground (and a surge protector always has a small current leakage), so this contradicts the manual ...? (what risk?) Why does my inverter sizzle when the panels are connected? (leakage to earth? two surge protectors per mppt is that too much?) Does anyone have a clear wiring diagram for wiring the PV part of the inverter (for Voltronics models or equivalent) to confirm my correct wiring(?Solar panels->fuse->Circuit breaker->surge protection->30m of cable->Circuit breaker->surge protection->inverter) How to protect against overvoltages if we must not connect to the ground? Thanks for any help/explanations.

hello thank you for these answers, I will continue to understand the operation of this inverter. for the clock I have the impression that in fact when you are in the menus it stops, last night I did not touch the inverter and this morning it is always on time! for consumption in SUB mode it's amazing because in SBU mode I'm at less than 10 watts. I still have the problem of the L2 output, it's a shame because I was planning to use it to operate my water heater thank you for your help and time spent assisting users on this forum

Hello everyone I am new in photovoltaics and I have just acquired an inverter, does it exist a up to date firmware for the Max II 11 kW Twin ? Mine was shipped with the version 75.00 for the Main CPU and 39.04 for the secondary CPU. There are some bugs like the management of the second output which does not cut off when the voltage is lower than the setpoint. There is also the clock that loses minutes...!? But not all the time, I do not understand. it remains a little "stuck" at 90 volts, but as soon as there is a little sun the voltage rises. at the moment I only have 220 volts DC(7s) at the solar panels, shortly I will have more than 400 volts (10/11s) and the voltage should rise faster. when I'm in SUB mode, even though the panels output enough, I'm still drawing 100/150 watts from the grid. Why ? thanks in advance any help/informations/firmware about this inverter/voltronic will be appreciated

hello I have an Axpert Max II Twin 11k and I have the same problem as you. Did you find a solution ? Thanks