Home Assistant Solar Optimizer: Unexplained EV charging behavior

[raeuberstephan]

Hello Home Assistant Community,

I'm seeking some general guidance on an issue I'm experiencing with the jmcollin78/solar_optimizer HACS integration (version 3.6) used for PV self-consumption optimization.

My Setup at a Glance:

PV System: Integrated with Home Assistant (via Fronius).

Grid Metering: Home Assistant receives grid import/export data from a P1 meter.

Controlled Load: A Tesla EV (charging rate is controlled via the number.tesla_charging_amps entity).

The Problem:

My Tesla EV is sometimes initiating charging, or increasing its charging rate, at unexpected times, particularly during the night (after sunset) when there is no PV production. This behavior is not only unwanted but also seems to contradict the core purpose of an optimizer designed for PV self-consumption.

What I've already checked/configured:

The EV charging device in Solar Optimizer has a low priority.

The min_on_time_per_day_min and offpeak_time parameters for the EV charging device are empty/not set.

The check_usable_template for the EV ensures it's only considered if the car is plugged in and set to charge via the optimizer's mode.

I have configured Energy buy price and Energy sell price with positive values in my general Solar Optimizer settings. My electricity contract does not have specific night tariffs.

My Observation during these events:

During the unexpected night charging, my grid meter clearly shows electricity import (positive Watt values), meaning I'm drawing power from the grid, not having any surplus.

My Question to the Community:

Under what general circumstances would the Solar Optimizer integration decide to initiate or increase charging of an EV (or any load) during the night when there's grid import and no PV production, especially when the device priority is set to "low" and no minimum runtime is enforced?

I'm looking for insights into potential misconfigurations or logical pitfalls within Solar Optimizer or Home Assistant that could lead to such behavior. Any pointers or general troubleshooting strategies for similar issues would be greatly appreciated.

Thank you for your time and help!

[jmcollin78]

Hello @raeuberstephan

Under what general circumstances would the Solar Optimizer integration decide to initiate or increase charging of an EV (or any load) during the night when there's grid import and no PV production

The only case I see is if the offpeak configuration is set. But as you said: The min_on_time_per_day_min and offpeak_time parameters for the EV charging device are empty/not set. so you shouldn't be in that case.

The only explaination I see is that the grid consumptio sensor is inversed: it should be positive if power is imported and negative if exported. And one common mistake is that, it is the consumption from the grid point of view and not from you home.

Please post some graphs with the sensors values you have configured.