RFID and PIN functions

RFIDs and PINs in the cFos Power Brain Controller and Charging Manager

Master RFID Card

The cFos Power Brain Wallbox is supplied with an RFID clip and a master RFID card. This has the following functions:
3 x hang up: Reset configuration to factory settings and restart
1 x hang up plus new card: Learn new card. This is stored under the (active or only) user of the EVSE.

The RFID reader of the cFos Power Brain Wallbox supports MIFARE cards with 13.56 MHz. You can buy these cards at a reasonable price. Many common cards that you may already have in your wallet also work. Unfortunately, EC cards and some credit cards cannot be read.

Positioning of the RFIDPositioning of the RFID

User and RFID management

Under "Users", the administrator can set up new users and then add them in the settings of the respective EVSE. As soon as at least one user has been added to an EVSE, this EVSE will only charge after authorisation with this user. This can be done by entering the user ID, a PIN or an RFID. You can set up multiple PINs or RFIDs for each user. For example, a household can be added as a user of an EVSE and all household members receive their own RFID.

Each user can also add further RFIDs or PINs with different functions and download a transaction log of their charging processes. To do this, they can enter a valid PIN, RFID or their user ID under "User" and then click "Manage user".

Show EVSE user when charging: If you give an RFID card a name, it will be displayed under "Start" in the EVSE tile when the user is charging under this RFID. However, the global user name can also be displayed if you "Allow name display" and the RFID card does not contain a name.

Note: User and RFID management is a function of the cFos Charging Manager, i.e. you only need to create users and cards in the "master", not in cFos Power Brain wallboxes that are connected as slaves. With other wallboxes, it may be the case that a wallbox only informs the Charging Manager of a read RFID card if this card was previously learned in the box itself.

Step-by-step instructions for setting up charging authorisation at an EVSE

  1. Screenshot user settings
    Main menu "User" -> "Add User". A unique user ID is generated. Set user name -> "Save".
  2. Under "EVSE Assignment", you can now select the EVSEs at which the user is allowed to charge.
  3. Now you can enter a PIN or RFID manually or learn one. After clicking on "Learn", place the RFID card on the corresponding EVSE. click on "Save".
  4. You can configure a name, functions and phases for the RFID card created in this way.

Map functions

RFIDs (and PINs) can have other functions besides charging authorisation. You can also create cards without authorisation, e.g. to switch parameters during charging. A card can have the following functions:

  • Stop and start charging in between.
  • Overwrite the charging current or cancel this overwriting.
  • Deactivate charging rules set for the user or set a new set of charging rules for the user.
  • Switch phases. Phase switching is useful if your wallbox does not have a counter that can determine the phases currently in use, but you want to charge cars at the wallbox that charge on different phases. Then you can inform the cFos Charging Manager, i.e. the load management, of this by hanging up the corresponding RFID. This is important, for example, in the case of PV surplus charging, as here the cFos Charging Manager needs to know how many phases the surplus will be divided among.
  • Change the priority of the wallbox for the current charging process.
  • Set a kWh budget
  • Set Charging Manager variables. Using Charging Manager variables, you can parameterise charging rules or values such as wallbox power, house connection power, etc.. You can dynamically switch these parameters using RFID cards.
  • Set Charging Manager outputs. This way you can use the RFID cards to switch devices.

RFID cards can be valid indefinitely or expire on a certain date or be limited to a certain number of uses. also change the wallbox priority for the current charging process and set a kWh budget. In addition, Charging Manager variables and outputs can be set. This way, you can use Charging Manager variables to parameterise charging rules or set values. With Charging Manager

Note: Instead of using the RFID card, you can also authorise charging using the cFos Charging Manager app. Note: You can also install an external (central) card reader and transmit the RFID entries to the Charging Manager via HTTP request. The Charging Manager version under Windows and Raspberry PI supports the connection of a USB card reader and the transmission to a running Charging Manager (also cFos Power Brain Wallbox).

IDSecret ID of the card. This is used to select the card and its function(s).
NameName of the card. Is displayed instead of the user name in the wallbox tile.
Authorise chargingIf at least one RFID card has this option ticked, charging must be authorised.
(De)activate chargingTicked: Placing the card on the charger activates and deactivates the charging process.
(De)activate user charging rulesTicked: Placing the card activates or deactivates the user loading rules.
Overwrite charging currentRetain = Nothing is changed to the charging current with this card. Do not overwrite: Overwriting the charging current is deactivated when the card is hung up. Numerical values in mA: Set max. charging current to value.
PhasesRetain: Do not change the phases, other values: Set the utilisation of the phases during charging.
Overwrite charging rulesTicked: The user charging rules used for the current charging process are those on the RFID. If no charging rules are stored on the RFID, the user charging rules are deleted for the charging process.
Add ruleAdd charging rules that are optionally used instead of the user charging rules for the current charging process.
PriorityCharging priority for load management. "Maintain" means that the priority is not changed when this RFID card is placed on the charger. "Do not overwrite": Any priority that differs from the wallbox is deleted for this charging process in the user settings (the priority set in the wallbox applies). Otherwise, the numerical priority that can be entered in the combo box is used for the current charging process.
ValiditySpecify whether the RFID card is always valid or only until an end date. It can also expire after a configurable number of uses.
Charging manager variableA Charging Manager Variable can be set by inserting the card. This allows RFID cards to be used for control purposes and to change load management formulas, for example.
Charging Manager OutputA switching output can be set by inserting the card.
BudgetA budget stored on the card can be activated or a currently active budget can be changed by placing the card on the card. Information on the budget functions

Fixed RFID

You can also set a "Fixed RFID" for each EVSE in the settings. This is used if no RFID is applied and no PIN is entered before the charging cable is plugged in. This is particularly useful for OCPP, where a corresponding backend may only allow charging processes if an RFID (previously configured in the backend) is present. If you do not place another RFID, the fixed RFID is also used in the transaction log.

HTTP API and external RFID reader

Every cFos Power Brain Wallbox and also the Raspberry and Windows version of the cFos Charging Manager supports an HTTP API function:
r is the PIN or RFID (digits), d is an optional device id to select a specific EVSE. If no device id is selected, the Charging Manager tries to assign the PIN or RFID automatically.

This allows you to set up an external RFID reader (e.g. at a centrally accessible location) and enable the users of the EVSE(s) to authorise charging from there. Commercially available RFID readers on the USB port transmit the RFID by means of simulated keystrokes. You can connect the e.g. Raspberry version of the cFos Charging Manager to a USB RFID reader and this will then forward the RFIDs to your EVSE or another cFos Charging Manager, call with:
charging_manager rfid dest
is the address of the EVSE or the cFos Charging Manager that is to receive the RFIDs via HTTP API, e.g. If you are using a third-party EVSE that does not have an RFID reader, you can retrofit RFID functionality with the cFos Charging Manager.

cFos Power Brain configuration change with RFID card

You can use a Mifare classic 1K RFID card to change the configuration of the cFos Power Brain. For security reasons, you must first insert the master RFID card and then the card you have prepared.

To do this, you must save a JSON file in the memory area of the RFID card. This looks as follows:

    "pb": {
        "wifi": {
            "sta_active": true,
            "sta_ssid": "Mein WLAN",
            "sta_pwd": "password1",
            "ap_active": true,
            "ap_ssid": "Wundertüte ${SERIALNO}",
            "ap_pwd": "password2",
            "mesh_active": 0            
    "sys": {
        "admin_pwd": "password3"

You can omit properties that are not required. Properties with "sta_" change the access data of your cFos Power Brain to the home WLAN router. Properties with "ap_" change the access data for the WLAN access point that the cFos Power Brain can provide. "mesh_active" activates the mesh. You can also configure the admin password for the cFos Power Brain.

To create a JSON file, it is best to use a computer and a text editor that supports UTF-8 encoded files and can recognise errors in JSON files, such as missing commas. A recommended editor is Visual Studio Code, which you can download free of charge from the Internet. Customise our sample JSON file according to your requirements. It is only necessary to change the keys that you want to modify. Unspecified keys remain unchanged in the Power Brain.

Once you have finished editing, transfer the file to your mobile device. An easy way to do this is to copy the contents of the file and paste it into a Google Docs document, which you can then open on your mobile phone. Alternatively, you can send the file to your mobile phone via email or Messenger. Then select and copy the content of the JSON file to your mobile device.

For reading and writing RFID cards, we use the "NFC Tools" app from wakdev, which is available in the Google Play Store. However, it is possible to use other apps for the same task. You will need a blank RFID card for your configuration. Do not use your Power Brain Master card for this. Any card of the type "Mifare Classic 1k" is suitable. Start the "NFC Tools" app and navigate to the "Write" tab. Tap on "Add a record", scroll down and select "Data, Add a custom record". In the dialogue box that then appears, enter cfos / cfg as the content type Under Data, paste the copied content of your JSON file (usually by pressing and holding the input field and selecting "Paste"). Confirm with "OK" to return to the "Write" tab. Tap on the "Write" tile and hold the blank RFID card under your mobile device to transfer the data.

To use the configured card on your wallbox, first hold your RFID Master card against the wallbox until it starts to beep. Then hold the RFID card just described to the wallbox to transfer your configuration.