Set up charging infrastructure with Raspberry Pi

With the help of a Raspberry Pi and the cFos Charging Manager, you can add two important functions not only to our EVSE, but also to other EVSEes: intelligent load management and solar surplus charging. As an alternative to the Raspberry PI, you can also use a PC with Windows 10.

Application scenarios:
You have an EVSE and want to retrofit solar surplus charging and load management.
You want to set up a charging park with third-party EVSEs and your grid connection does not support all EVSEs with maximum power. The cFos Charging Manager regulates the charging power of the connected EVSEes as low as your grid connection allows.
You have a charging park with third-party boxes and a solar system and only want to charge with your solar surplus at certain times.

Requirements

Setting up EVSEs

  1. Open the cFos Charging Manager on your Raspberry Pi by entering the address of the Raspberry PI in your network in the browser and 4712 as the port, e.g. 192.168.2.111:4712.
  2. Register your EVSE in your network via WLAN (Modbus TCP/IP). Please use the manufacturer's instructions if it is not a cFos Power Brain Wallbox
  3. Add all your EVSEs to the settings. Use the following parameters for the device configuration: (Figure 1: Example for cFos Power Brain Wallbox)
  4. Screenshot of the settings for the EVSE setup
    • Device type: Select your EVSE
    • Address: the corresponding address in the form IP address:port, example: 192.168.2.150:4701
    • ID: will be filled in automatically
    • Optional: Attached electricity meter
  5. You can repeat this process as often as your licence allows. In the shareware version (without charge point licences), 3 charge points are available until the expiry date
  6. The configuration is now complete and your EVSEs are controlled centrally from the Raspberry Pi by an intelligent load management system

Setting up a solar surplus shop

(Version 1.7.1079)
For solar surplus charging, the cFos charging Manager requires reference values for the current. There are two possibilities for this:

  • Ask your electrician to install a bidirectional meter at the transfer point of the house connection. Suitable meters are, for example, Modbus meters or internal grid reference meters of your solar system(list of supported intermediate meters). In order for the Charging Manager to be able to calculate the mains supply independently of the charging of the electric cars, a meter with the role "consumption electric car" must ideally be configured for each EVSE in this configuration. If you do not require individual recording of the power / consumed kWh of the individual EVSEs, you can also set up one or more central meters with the role "Consumption EVSE" that measure the total power of the EVSEs.
  • You measure the generation output of your solar system and the household consumption without EVSEs. Ask your electrician to install a supported electricity meter for domestic consumption. Supported inverters measure the generation automatically, you then only need a meter for your domestic consumption.
    Home consumption - electricity generation = solar surplus

Step by step guide:

  1. Open the cFos Charging Manager user interface on your Raspberry Pi.
  2. Settings > Add Meter.
  3. Select your meter/inverter and add the device address.
  4. Under the Load Management role, now select:
    • Grid reference, for your house transfer point meter. If you have installed a grid reference meter, the Charging Manager will always use this as the reference value
    • or consumption or generation for your home consumption or electricity generation
    Example for SunSpec Solar Inverter
  5. You can configure solar surplus charging for each individual user or for each individual EVSE.
    Users: Open the RFID/PIN tab at the top of the bar. Once you have selected a user, click on Edit.
    EVSE: Open the settings for the respective EVSE. You can see an example on image 1 of this page.
  6. Add rule.
  7. Use the following parameters:
    Screenshot of the settings for solar surplus charging
    • Solar
    • Start current limit: We recommend a value of 6500 mA (or a value slightly above the minimum charging current of 6A). Excess charging is thus carried out from a feed-in of 6.5 A
    • Solar surplus
  8. Save the settings.
  9. For more details on surplus charging, balance surplus charging, phase use and electricity storage, see our surplus charging documentation
  10. The configuration is now complete and all registered EVSEs will only charge in the event of a solar surplus if the corresponding user has been selected.