shubham avatar image
shubham asked

How is AC Consumption calculated? What do the values in VE_Bus_charge_power signify?

I am trying to achieve a power balance for my system. However, i often find that the power balance is achieved when I consider the VE_Bus_charge_power instead of Battery power and PV-DC power. How can I understand the significance of values given by VE_Bus_charge_power.

I tried to compare those values with the power from PV and the Battery charging/discharging power; however the values for quite different. The difference if much more significant during the no-sun hours (i.e. when the PV is idle). More here.

I am aware that the AC Consumption values from the VRM Portal are calculated values. I would like to know if this somehow defines the values in VE_Bus_charge_power?

Any leads will be highly appreciated. Thank you!

Screenshot from VRM for my installed system:post-4.png

MultiPlus Quattro Inverter ChargerVRMBMV Battery MonitorbatteryVE.Bus
post-4.png (59.5 KiB)
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shubham avatar image shubham commented ·
@kevgermany would you have an answer to this? Or could you simply explain what the VE_Bus_charge_power says?


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kevgermany avatar image kevgermany ♦♦ shubham commented ·
Sorry, no. You've covered all I could guess.
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1 Answer
JohnC avatar image
JohnC answered ·

Hi @Shubham

You'll drive yourself crazy trying to work out a power balance. The main reason is that the sampling times are different, so nothing adds up with the inevitable shifting of the figures. And system losses.

Not sure what you mean by 'VE_Bus_charge_power', but from your other post I think it's the Quattro tile at the bottom. That's like a de-facto battery monitor that you can select in the GX. When selected it also shows as a battery in the Marine MFD app. See the batt symbol?

For me (using DVCC), the V and A come from a Smartshunt, and the W seems to be much the same as the AC load from the Multi late at night when no other inputs or loads exist. It may even be a best-effort W balance in itself? It's a DC display, so you'd expect W = VxA, but for me it's always ~30W short. I accept that as the system loss from my Multi 5000 with minimal loads (<200W).

You might even find the MFD app better to attempt a balance, the figures are laid out differently. Type "venus.local/app/" in a browser.

Have fun..

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