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I agree with you, it is not serious but it is worrying, certainly some influence on cycles has it !. In this Axpert VM 3 seems to be better than Kodak or Axpert MKS as this video (in Spanish) shows well. https://www.youtube.com/watch?v=7-AJvnqgFsQ I confirm that Axpert VM 3 in SUB mode doesn't use the grid without reason, and when it does it takes only the missing quota. I had watched this video before buying it !! Unfortunately that doesn't do the same in SBU mode. When battery reaches 100% the solar charger DON'T switches off but always uses a different PV quota, as I said .... "without apparent rule" ... it uses the battery more often if the load is low. It is my idea (or maybe it's just fantasy!) That the inverter, after charging, must reduce the voltage produced by the Charge Regulator which at this point is very similar, if not equal to the batteries themselves. The flow that is created cannot therefore have a precise direction and the software cannot control it, but sooner or later the technicians will succeed !! Take comfort in thinking that the effect on battery cycles is probably not so heavy, in the meantime try to concentrate the loads in the morning or during the battery charge. I try to persuade my wife to iron or use the washing machine in the late morning but ...... it's more difficult than changing the inverter software !!

Yes, of course, the PV at that moment has great capacities but it uses it partially and alternately without apparent rule, and alternatively uses batteries. Only when the batteries have discharged by 1% does it use all available PV power for charging and the rest for charging. It would obviously be preferable to leave the batteries alone if it doesn't need them! The thing that seems positive is that after a month of work the 3 new batteries, which have never completely discharged, only mark 10 cycles done, while the first battery that has worked for a month alone has 45 cycles. If the data is correct and reliable, it means that the partial discharges are really considered in proportion. Thanks !

Hello everyone, now I have mounted all 4 batteries (9,6Kwh) and it seems to me that the system is right for me. With 3Kw of PV In a month I have never taken a single Kw/h from the grid, on average the batteries are fully charged at 1 or 2pm and this also allows me to overcome even 1 or 2 days of bad weather. Unfortunately, in the afternoon, when the charge is complete, Axpert VM III still uses the batteries! (the setting is SBU), especially if the load is very low, there is no real rule !, the only certainty is that when the batteries go down 99% it recharge immediately. The only solution is to set SUB at that moment, in this case it behaves well and uses only PV for the load, bypassing at grid only when PV is insufficient, but I don't know how to automate this setting !, my goal is do not use grid! I don't like it but that's it! As partial solution, to reduce the time of this nasty behavior I bought an inexpensive 80l electric boiler with a timer that operates it only from 10AM to 5PM. I put the output of the boiler as the input of the gas boiler, so if the water is already hot the gas boiler does not start. Therefore, I save some gas for domestic water and delays the full charge of the batteries.

Hello everyone and sorry again my english. I have tried 100 ways to use Multisibcontrol to monitor my 4 Pylontech us2000c, it seems to be very simple but SOMETHING IS WRONG! The BMS is working properly (the battery indicator on my Axpert VM 3 inverter is blinking). I tried both to connect the master battery to my PC (win 8.1) via the console port (RJ45 pins 3,6,8 to DB9 2,3,5 pins and a DB9 to USB converter) and also via (B/485 port 7,8 pins to an USB to RS485 Converter Adapter) In both cases I can see the USB port on Pc but when I assign it to Pylon via the Setting menu it always appears: ... Pylon started 0x ... Pylon stopped ... Pylon started 0x ... Pylon stopped .... .... and no data appears!!!. My inverter instead connects perfectly by its the MiniUsb-Usb cable and also with its Rj5-DB9 cable and the same DB9 to USB converter used for the batteries (and this means that at least the DB9 to USB converter is good) I put some pictures, but I don't understand what I'm doing wrong, does the BMS have to be woken up? ... I tried to change Pc, ..... to deactivate .net, framework 4.5 (leaving only framework 3.5) ..., to invert pins .... I also tried to turn the master battery off and on while it was connected to the PC but nothing changes! Some idea? Thanks

Hi Coulomb. your theory is interesting but I have another one that is a bit fanciful! The problem starts before charging, with that sharing of energy between PV and battery. In my opinion, once the charge is complete, the inverter does not physically close the connection with the battery, so battery input / output and PV out are the same physical equipotential node from which Axpert takes the energy for AC load. It is therefore unable to guide or know whether the energy is coming from the battery or the PV. As soon as the battery drops to 99%, as you said, the BMS informs Axpert to recharge, the voltage on the node rises and the energy flows rightly towards the battery and towards the load, when the charge is complete the game starts again !. I therefore think that, by mistake, due to inability to do otherwise or for simplicity of operation, the designer decided this. However, I hope it is not serious too, the BMS will know what it is doing! But I don't know how the battery life cycles are counted, complete discharges .... partial discharges ... even minimal discharges !!. My system is totally "do it yourself", I have not chosen to put power into the grid (here in Italy it would be convenient to do so, but a lot of bureaucratic permits are needed) I would like to take as little as possible from the grid, so 70% of the cost is for batteries only!

..... I forget to send you photo and logs(every 30s) of Axpert activity, as you can see charge and discharge alternate , note that PV can supply more powerand the battery has already been fully charged for several hours . As soon as battery goes down 1% ...recharge begin.. DataLog_929321091013827.xls

Is also my opinion that a slight discharge does not hurt, but I assure you that after a while it recharges again, with at least 10 / 15A, for a short time. it doesn't feel like a maintenance charge or even an equalization. The equalization among other things, as well as other parameters is delegated to the BMS Pylon, I can only set parameter 12 (46V) and parameter 13 (49V). I'll wait the new batteries and I'll see if something will change!! Thanks for support!!

this is not my goal, it is to use PV always when available, battery when PV is not available, and utility when nothing else is available exactly as SBU says.!

Hello everybody, (sorry my bad english) I ask for help for my Axpert VM 3 5kw, it is connected to a 3Kw PV and to a single 2.4kw Pylontech (3 more will arrive soon). It is set as SBU (solar battery utility) priority and charging to OSO charging priority(Only solar can charge battery). The BMS works fine, (the battery icon is blinking) and the inverter also works as expected except for a situation in "Battery mode". When the battery is not full it takes all the energy from the PV, power the load and with the rest charge the battery, everything is perfect !, ..... but .... when the battery is fully charged, it takes the energy (1-2A ... 5A) directly from the battery and a little also from the PV (which has a lot of availability). After a few minutes, when the battery is slightly discharged, it takes all the energy from the PV, powers the load and charges quickly the battery again (100%). This process is automatic and transparent, no errors and good functioning, but I have a strong doubt !! May be these continuous small discharges and charges reduce the life cycles of the expensive battery? Why doesn't it respect the set priority? It is not Solar first, Battery after, and Utility after, but Solar and Battery together and Utility after !. Can I do something to correct? If, in this situation, you set SUB, it works well, it takes all the necessary energy from the PV and nothing from the Utility, but obviously I can't keep this setting in other situations. Any suggestions? thanks a lot!!