Short answer
With several charge points on one connection, a system is added that shares out the available power and keeps track per point of who charged what. For an owners' association (VvE) permission from the meeting is needed and it must be clear who pays for the electricity. Technically it is very doable, even in an existing underground car park.
Who this article is for For boards of owners' associations (VvE), managers and businesses that want more than one charge point. For a home with one charger, connecting an EV charger at home is the right article.
The real issue is sharing
One connection, several cars. If everyone charges at full power at once, the main protection trips. The answer is a system that measures and shares: the available power is divided over the active points, and what the building itself uses is deducted first.
In practice that means nobody always gets the maximum, and that is fine. A car that stands for twelve hours at night needs only part of the power.
Growing without redoing everything
The most sensible set-up is a distribution board with spare capacity. You run a heavy supply to the parking area or car park once, put in a board that can handle twelve or sixteen points, and connect the points that are needed now.
When another resident joins, that means adding a circuit and mounting a charger. Without that set-up the fourth resident pays for the whole infrastructure all over again.
Billing per user
There are three ways, from simple to complete:
With a few points metering and settling up is enough; in a large block you do not want to have to think about it.
Own kWh meter per point. Simple and reliable. Someone reads it and settles up. Works fine for a handful of points.
Chargers with their own metering and a card. The charger knows who is charging and passes the data on. This involves a service from a provider.
Fully managed system. The owners' association gets an overview, the resident an invoice. More convenience, but also subscription costs.
Which suits you depends mainly on the number of points and whether the board wants to have to look after it.
Fire safety in an underground car park
In an underground car park there is more to it than just connecting:
- the cabling belongs in metal trunking or conduit, not loose along the ceiling
- there should be a central shut-off that switches off all points at once in an emergency
- the fire service and the insurer sometimes have their own requirements, and these differ per municipality
I discuss this with the board as standard and put it in the quote, so there is no argument about it afterwards.
What the process usually is
- Site survey: connection, space, route
- Plan with a distribution board, number of points now and later
- A quote the residents can put to the meeting
- Installation, usually in one or two days
- Handover with a test report per point
For the testing and the report the same applies as with every installation I hand over, see NEN 3140 inspection and the business page.
From my own work
In a block of flats it started with two residents who wanted to charge. I put a distribution board in the car park with space for twelve points and its own kWh meter per point. The first two have been fitted, the rest are connected when someone joins. Each new resident pays only for their own point, not for the whole system again.
When to call an electrician
- Two or more charge points are going on one connection
- It is for an owners' association (VvE), an underground car park or a business site
- Consumption has to be billed per user
- There is too little power on the connection
I make a plan with a distribution board that more points can be added to later. See business customers and request a quote.
Frequently asked questions
Does the whole owners' association (VvE) have to pay towards a charge point?
Usually not for the point itself. But the meeting does decide on the shared infrastructure, so on the distribution board and the cable to it. A set-up with space for later makes that conversation easier.
How is electricity billed with several users?
With its own kWh meter per point, or with a system that keeps track per card of who charged. With a few points metering and settling up is enough.
Can this be done in an existing underground car park?
Yes. There is more involved then: cabling in trunking or conduit, a central shut-off and sometimes requirements from the fire service or the insurer.
Further reading
EV charger at home: single-phase or three-phase, and which protection
The choice depends as much on your car as on your connection. With the costs, the RCD debate and why load balancing is not an optional extra.
Which cable to the EV charger, and what the distance does
The further the charger is from the meter cupboard, the thicker the cable has to be. That is usually the item that decides the price.
Load balancing: why your main fuse can cope after all
Without load balancing the car keeps charging at full power while the oven and the tumble dryer are on too. With load balancing the car automatically charges more slowly.
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