Multiplying the DC Volts by the DC amps gives 542W not 494!!
This is from the multiplus device page. So either the firmware in the multi cannot do the sum correctly, or the GX is causing this error…
There should be no reason why the dc power is not the product of the V * A.
So you’ve noticed it too… 
Don’t know why is that, but the shown DC power is oddly close to the AC-OUT power… Strange, isn’t it?
Don’t know if it’s intentional to mask the no-load power consumption or is a bug…
In my case MP2-3K, about 30W difference, in your case about 50W difference.
But leaving the conspiracy theory aside, it’s possible to be a bug. 
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I have made the same observation as Alex that the power quoted seems to be the ac power being generated by the inverter not the input dc power. Bug or by design ???
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DC Power and AC-OUT have small differences from time to time, but this could be put on behave of different update rates on system’s d-bus.
In my case, first the AC-OUT is updated and after a few milliseconds, the DC Power follows it with the same value.
All four, AC-OUT, DC power, DC voltage and DC current (from which last two you can compute the real dc power) are sent by the inverter and the VE.Bus driver publishes them on the d-bus.
And dont forget you have conversion losses you canot make 48v to 220v without conversion losses. And the 98% are only on a sweet spot
Sure there are conversion losses, so I would expect that the Power on this line to be the DC input power, as the product of DC V * DC A.
AC input power at the time was -480W ( Not an error, this is operating in ESS mode 1 with -480W set point).
I’ve also been looking at the F frames (dc & ac bus parameters) from a Mk3 on another system, this has DC Voltage, and DC current values, but no DC power. So it looks like the power calculation is done by the Cerbo, and there should be no excuse for not getting it right.
On the subject of F frames, the protocol gives the following:-
I’ve found that the ‘inverter current’ for a 2 unit system with the inverters in parallel seems to already be multiplied by the “Inverter Factor”; with values of 20A when the measured input for that inverter is 10A. As the inverter DC currents are not guaranteed to be identical, it seems that reading the dc current from each inverter and doing a sum would be more accurate than just assuming double on the 1st inverter. Note the value in the slave inverter is also doubled.
The only problem with that approach is that the two readings are not synchronous, so if the DC current is changing fast, then this will not give an accurate result.
Cute display, not seen this one before, certainly not in the standard GUI-2..
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As the Cerbo’s infos are spread on too many pages for my taste, I’ve made a summary-like page and added it to the Cerbo’s main menu, in order to have all the infos at a glance.
Also coloring different info help finding the relevant info much quickly on a crowded page… 
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