Affected devices

cFos Power Brain wallboxes (11 kW, 22 kW, 22 kW L) and cFos Power Brain controllers sold separately with controller board revisions 3.0 to 3.2, supplied between May 2024 and December 2025, on which firmware earlier than version 2.12.2 is installed (e.g. 2.10.0 or 2.8.1).

If you are unsure whether your device is affected: Check the firmware version as described below. If it is older than 2.12.2, please update it in any case.

What is it about?

The Wallbox uses a built-in sensor to monitor whether a DC fault current is flowing, and then shuts down the charging process. In firmware versions prior to 2.12.2, this monitoring function may fail unnoticed due to a software bug. If a DC fault current subsequently flows – for example, due to a fault in the vehicle – the charging process will not be interrupted.

What is the risk?

A continuous earth fault current can permanently render the residual current device (RCD, Type A) in your domestic electrical installation ineffective. It will then no longer protect the other circuits in the house either. If an insulation fault occurs there at a later date, there is a risk of electric shock. We are not aware of any accidents.

What do you need to do?

A wallbox with firmware version earlier than 2.12.2 must not be used to charge cars until the update has been installed. The update is free of charge and takes just a few minutes.

• Open your browser and go to the IP address of your wallbox. If you do not know the IP address, you can find it on your router. The installed firmware version is shown in the top right-hand corner.
• In the top menu bar, open ‘Configuration’ and scroll down to the ‘Firmware Update’ tile.
• Select ‘Stable Release’, accept the licence terms and click ‘Update now’. The Wallbox will then restart.
• Please check that, after restarting, the version displayed in the top right-hand corner is at least firmware 2.12.2.
• Scroll down to the ‘Hardware’ tile and click on ‘Self-test’. The DC sensor error counter must not increase.
• Press the test button on the residual current device (RCD) that protects the wallbox and check that it trips.

Please confirm the update by sending a brief email to cfos-support@cfos-emobility.de, stating the serial number.

If the Wallbox has not yet been installed or commissioned, please carry out the update immediately upon commissioning, followed by the self-test.

If you are a dealer or installer, or if you have passed the Wallbox on to someone else, please forward this information to the operator.

Help and Contact

We can help you free of charge by telephone or via remote access; alternatively, your electrician can carry out the update. Please email us at or cfos-support@cfos-emobility.de, providing your serial number, telephone number and the times when you are most likely to be available. We will then ring you back.