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Build 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 ours, but also to other wallboxes: intelligent load management and solar excess charging. As an alternative to the Raspberry PI, you can also use a PC with Windows 10.

Usage scenarios:
You have a wallbox and want to retrofit excess solar charging and load management.
You would like to set up a charging park with third-party boxes and your network connection capacity does not support all wallboxes with maximum capacity. The cFos Charging Manager regulates the charging power of the connected devices down to the extent permitted by your network connection.
You have a charging park with external boxes and a solar system and only want to charge with your solar surplus at certain times.

Requirements

Setting up wall boxes

  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 the port 4712, e.g. 192.168.2.111:4712.
  2. Register your wallboxes in your network using WLAN (Modbus TCP/IP). Please use the manufacturer's instructions for this if it is not a cFos Power Brain Wallbox.
  3. Add all of your wallboxes to the settings. Use the following parameters for the device configuration: (Image 1: Example for cFos Power Brain Wallbox)
  4.  Screenshot of the settings for setting up the wallboxes
    • Device type: select your wallbox
    • Address: the corresponding address in the form of 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 license allows. In the shareware version (without charging point licenses) 3 charging points are available to you until the expiry date.
  6. The configuration is now complete and your wallboxes are controlled centrally from the Raspberry Pi by an intelligent load management system.

Establishment of solar excess charging

(Version 1.7.1079)
For solar excess charging, the cFos charging manager needs reference values for the electricity. There are two ways to do 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 electricity meters for your solar system (list of supported intermediate meters). In order for the Charging Manager to be able to calculate the electricity purchased independently of the charging of the electric cars, a meter with the role of "E-car consumption" must ideally be configured in this configuration for each wallbox. If you do not need an individual recording of the power / consumed kWh of the individual wallboxes, you can also set up one or more central meters with the role of "E-car consumption", which measure the total output of the wallboxes.
  • You measure the generation output of your solar system and the house consumption without wall boxes. Ask your electrician to install an assisted home utility meter. Supported inverters measure the generation automatically, you then only need one meter for your house consumption.
    House consumption - electricity generation = solar surplus

Step by step instructions:

  1. Open the user interface of the cFos Charging Manager on your Raspberry Pi.
  2. Settings > Add counter.
  3. Select your meter/inverter and add the device address.
  4. Now select under the load management role:
    • Grid purchase for your house transfer point meter. If you have installed a purchased electricity meter, the Charging Manager will always use this as a reference value
    • or consumption or generation for your home consumption or electricity generation
    Example for SunSpec solar inverters
  5. You configure excess solar charging for each individual user or for each individual wallbox.
    User: Open the RFID/PIN tab at the top of the bar. When you have selected a user, click on edit.
    Wallbox: Open the settings for the respective wallbox. You can see an example on picture 1 of this page.
  6. Add rule.
  7. Use the following parameters:
    Screenshot of the settings for solar excess 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 carried out from an infeed of 6.5 A.
    • Solar excess
  8. Save the settings.
  9. You can find more details on excess charging, balance-sheet excess charging, phase use and power storage under our excess charging documentation
  10. The configuration is now complete and all registered wallboxes only charge if there is excess solar power if the corresponding user has been selected.