Sustainable Garage Wiring: Electric Car, Conductor Cross-Section

Hello everyone,

Which conductor cross-section would you choose for future-proof wiring to the garage? So far, a 16A CEE socket and several 230V sockets are planned in the garage. My consideration is which power and cross-section are needed if an electric car is to be charged there later. It is speculative, but maybe someone else has also thought about this. The cable length between the distributor in the house and the garage is about 15m. A sub-distribution in the garage is not planned so far. The individual sockets are to be protected in the house. The large cross-section for the future electric car can initially be protected with a smaller fuse.
Thank you very much

Perhaps the Tesla Model S could be used as a reference for the future. It has the largest battery capacity of 100 kWh. The onboard charger has 11 kW, that is 16A three-phase current. Logically, the charger requires about 10 hours for a full charge.

For the 16A three-phase connection, depending on the installation method and cable length, you most likely only need a 5x1.5 mm² cable, but I would install 5x2.5 mm², that way you are on the safe side and it costs almost nothing.

On the other hand, there are of course also dual chargers, Superchargers with 120 kW, and so on. However, I would definitely not bet now that one might need this later. Then we are talking about cross sections of 50 mm², and those are already very difficult to install and also slowly become expensive. As a maximum, I would probably install 5x4 mm² to a CEE32 socket and protect it with 32A.

Have three phases / three-phase current installed. More is nonsense anyway; the house connection usually only has 14.5kW, with electric heating sometimes over 30kW. But at 120kW or more, the power supplier will probably kindly knock if the application states "single-family house, one residential unit."

Had also thought about it during our construction and called BMW. I was advised to install high-voltage power instead of the usual 220-volt sockets in the garage.

the house connection usually has only 14.5kW

With us, up to 30kW is standard and therefore cost-neutral.

I would lay a larger empty conduit. This way, you are very flexible regarding the cable cross-section.