I would like to share my enthusiasm about the HACS integration EV Smart Charging.
I have a BMW EV and a Webasto wallbox. I want to minimize my electricity bill by taking advantage of dynamic electricity prices (in the EU).
Looking for ways to do that I discovered the EV Smart Charging integration. And it is amazing.
EV Smart Charging can use one of three sources for the ‘day ahead prices’. I use the ENTSO-e Transparency Platform integration for this.
You can configure how to read the current and target SoC for your EV. In my situation I use the BMW Connected Drive integration for that.
You can configure how to detect whether the EV is connected to the wallbox. In my case I have used the Modbus integration to control the Webasto Unite wallbox. I use this to check whether the EV is connected and the session is authorized.
You can configure how start and stop the charging process. In my case I use the BMW Connected Drive for this.
I now have this operational for the normal use case: charge the EV to the fixed target SoC (80%) each time the car is @home. Taking into account todays and tomorrows prices.
I have bought a Raspberry Pi to run this on. And managed to keep the power consumption of the ‘always on’ Raspberry Pi down to 1 or 2 watts. Otherwise I would not save any cost by using this.
Currently I’m trying to add a simple interface to manually override this process for use cases:
- I need the EV charged the day after tomorrow, because I’m working at home tomorow.
- I need the EV charged immediately now and after that optimize for cost again.
- I need the EV charged to 100% SoC once because I need to make a long trip. And after that revert to the safe target SoC of 80% again.
For this I will be using the HA companion App on my smartphone.
Set up https access for extra security by encrypting and thus protecting the HA credentials.
Added the Wireguard addon to create a VPN from the internet to HA.
With this setup I can use the App to control the charging from a simple dashboard with some buttons for the different use cases. Hopefully so simple that my home mate can also use this 
So if you have an EV and want to optimize your charging costs, give this I try.
My ‘business case’ is as follows:
- I pay €0.40 per kWh on a public charger (11kW)
- I pay €0.30 per kWh at home with a fixed tarif contract
- I pay €0,20 per kWh at home with a dynamic tarif contract. Ofcourse on average.
To get this benefit al the time, I have spent €150 on my HA equipment
So give it a go as well.