Billing and use of calibrated meters

The MessEV stipulates that only calibrated meters may be used for billing purposes. In the EU, MID certified meters are considered calibrated. MID certification can be recognised by the 'M' enclosed in a rectangle with a 2-digit year of manufacture. To the right of the rectangle is the number of the certifying authority.

In Germany, an EVSE with integrated meter is considered a "measuring device" and must be calibrated if it is to be used for billing purposes. So if you want to use our EVSE with built-in MID certified meter for official billing purposes, you must remove the meters and install them in the distribution cabinet from which your EVSE is supplied with electricity.

So there are three scenarios:

  1. You only use the built-in meter for load management. Then it doesn't matter whether it is MID certified. Meter readings are for information only.
  2. Your employer, landlord, etc. only requires the use of a MID certified / calibrated meter. Then you can use the MID certified meter installed in the EVSE as supplied.
  3. You need meter readings for official billing purposes. In this case, you must install the meter from the EVSE in a separate control cabinet / distributor. The meter must be readable for the end user.

You must therefore decide on a case-by-case basis how to proceed in your specific application. On request, we can supply the cFos Power Brain Wallbox with a built-in or external meter.

Billing of charging processes of several persons at one EVSE

For the accounting of charging processes of different users at an EVSE, the cFos Charging Manager offers a transaction log in which the user IDs and RFIDs or PINs of the users are stored in the form of a CSV file, together with the kWh charged. This can be analysed by machine, e.g. loaded into Excel. Here, the cFos Charging Manager (so far) only offers the transaction log as an aid. If you want to account for the individual charging processes of different users in compliance with calibration law, you must operate an EVSE that can output signed meter readings at the start and stop of a charging process. We are currently working on a corresponding variant of the cFos Power Brain Wallbox and on the cFos Charging Manager being able to hold these signed meter readings for "official" billing purposes.