ᐅ Designing Electrical Load Requirements for Garage and Electric Vehicle Chargers

Hello!

What capacity and cable cross-section are you installing in your garage? My utility provider normally supplies 63A and 30kW capacity for the house. Each additional kW costs 95 (net).

Since in a few years there will probably be two electric cars added, this needs to be planned for. Currently, I’m undecided between 11kW or 22kW per wallbox. In the second case, the total 30kW capacity obviously wouldn’t be sufficient.
The cable cross-section will likely be NYY 5x16mm² (5x0.63 inch²).

What have you planned or implemented?

Although I have an older house, I can tell you that the energy supplier has to approve high power consumption. For example, we have two instantaneous water heaters, each with 20 kW, and this is already “not allowed” in the sense that only one can operate at a time. The other is deactivated by a load shedding relay during that time. Even though the water heater uses only about 5 kW while showering. But still!

That means you can’t just install two 22 kW wallboxes without permission. Depending on the energy supplier, sometimes only 11 kW is allowed.

By the way, we don’t have a wallbox and two electric vehicles. One only charges at 2 kW from a regular outlet, and the other, although capable of 22 kW, also charges at a regular outlet as a backup—especially during daytime when the photovoltaic system is running.

In the near future, a mobile 11 kW charging solution is planned. So, not a wallbox but an adapter like the go-eCharger. We already have a red CEE 16A three-phase socket here at the house. This would need to be extended about 30 m (100 feet) to the garage. Multiple EVs could be charged there, but not simultaneously.

Since our EV with the smaller battery (22 kWh) charges quickly enough even on household sockets, it’s not urgent. What’s more important to me is being able to limit the charger to 6 kW to ensure that our photovoltaic system can cover the demand.

I wouldn’t install two charging stations for two electric cars. We have one electric car and one charging station. When the second electric car arrives, we will still only have one charging station. The cars are not plugged in all day (especially if they can be charged with 22 kW). Our E3DC charging station can also charge two cars at the same time, one at 22 kW and the other at about 3.7 kW.

MelanieSH schrieb:
I wouldn’t install two separate charging stations for two electric cars.
We have one electric car and one charging station. When the second electric car arrives, we’ll still use only one charging station. The cars aren’t plugged in all day anyway (especially not if they can be charged at 22 kW). Our E3DC charging station can also charge two cars simultaneously, one at 22 kW and one at around 3.7 kW.

And the cable reaches all the way over to the other side?

I believe we have a 7-meter (23 feet) cable. Double garage, with the wall box located in the center.

We have 16A and 32A in the garage. That should be more than enough. However, I’m not keen on having an electric car in the house just yet. I’m not interested in emotionless lithium batteries that are produced under harsh conditions involving child labor. My health is important to me, and I’m not one for conspiracy theories.