Is your feature request related to a problem? Please describe.
The problem here is, my home battery may reaches 100% in the morning if the prices were low for a longer time. But I want to left some "space" for the case to charge the home battery from the sun at the day.

Describe the solution you'd like
In the first iteration it would be sufficient to have an additional field to define the home battery max SOC.
Internally beside the simple price limit validation the current home battery loading state is evaluated against the new configured homeBatteryMaxSOC. For sure, internally a trash hold must be involved so the home battery is not charged / discharged in a short amount of time.

Describe alternatives you've considered
Do not use evcc for this but a third party system , e.g home-assistant .

Additional context
none