I think the charging power entity is not reading correctly.
The most my car is supposed to be able to draw is 11kW
Looking at the picture, I was producing 13.11kW of solar and feeding 540W of that back into the grid. The charger indicates that it is pulling 14.81kW giving me a negative house consumption which can’t be right.
Is there a setting in the wallbox unit or the integration to calibrate this power reading (eg voltage selection or something) that I’m missing or is this a bug?
Hi @Wilko475,
I have been experiencing the exact same issue with my Wallbox Pulsar Max, and I think I can point you in the right direction. Your assumption is spot on: the power reading is definitely wrong, which breaks the energy dashboard math and results in that negative house consumption.
In my setup (a single-phase 7.4 kW / 32A Pulsar Max), I noticed that the integration occasionally reports bizarre Voltage spikes—sometimes indicating over 500V!
Because the Power value is calculated by multiplying Voltage and Current ($P = V \times I$), and the Current (Amps) reading seems to be perfectly accurate, the artificially inflated Voltage causes the reported Power (kW) to skyrocket.
I know my actual grid voltage is fine because I have a Shelly meter in my main panel and another Wallbox (Pulsar Plus) right next to it, both showing a perfectly stable 220V-230V.
What you should check to confirm:
Take a look at the Voltage entity for your Wallbox in Home Assistant while the car is charging. Since your car pulls a max of 11kW, you are likely on a 3-phase setup. Check if one (or all) of the phases is reporting an impossibly high voltage number.
Hardware or Bug?
I haven’t fully narrowed down if this is a hardware issue (e.g., a faulty internal voltmeter specific to the Pulsar Max line) or a glitch in the OCPP integration parsing the data. However, since the Current (Amps) being delivered to the car is correct, it seems to be just a data reporting annoyance rather than a physical charging issue.
Hope this helps you troubleshoot! Let us know what your voltage entities are showing.
Yeah that thought had occurred to me but I don’t have a voltage or current sensor to go off. I might have to put an external monitor on it and calculate it myself