Before an EV charger goes on the wall: what should be checked first?

The charger is only the visible part

A home charge point can look like a fairly simple product: a box on the wall, a cable and an app. The important work starts before any of those things are fitted. An installer needs to understand the property’s electrical supply, the existing installation, the earthing arrangement, the route to the parking position and the load that will be added.

That is why two houses with the same car and the same charger may need different solutions. A good survey is not an obstacle before the installation. It is the work that allows the installation to be safe, tidy and appropriate for the way the household will use it.

Mode 2 and Mode 3: what the labels actually mean

A portable charging lead with an in-cable control box is generally described as Mode 2. It connects through a suitable socket and incorporates control and protective functions in the lead. It can be useful for occasional or contingency charging, but a socket, its circuit and the surrounding arrangement still need to be suitable for a long-duration load.

A permanently installed domestic charge point is normally Mode 3. It is supplied by a dedicated circuit and communicates with the vehicle. This is the usual arrangement for regular home charging because the equipment, circuit and controls are designed together for the job.

Mode numbers are not a substitute for an assessment. Even a very capable charge point cannot correct an unsuitable supply, poor earthing or an ill-considered cable route.

Can the home support the additional load?

The existing demand and the rating of the incoming supply need to be considered. That does not mean every home requires an expensive supply upgrade. It may mean selecting an appropriate charging rate, using load management, or coordinating with the distribution network operator where necessary.

Load management can reduce charging power when demand elsewhere in the home is high and make more capacity available when other loads fall. Used properly, it is a considered design tool—not a way of avoiding checks that should have been completed.

• The incoming supply and service equipment.
• Existing large loads such as electric showers, heating, cooking equipment or solar and battery systems.
• Available capacity at the consumer unit and the suitability of the proposed circuit.
• Whether monitoring or load-management equipment is required.

Earthing and protective devices are not optional details

An electric vehicle is a large conductive object used outdoors, often while a person is standing on the ground. The earthing arrangement and protection against electric shock therefore require particular attention. The correct solution depends on the supply and the charge point’s own protective features.

Mode 3 charge points require individual residual-current protection selected for the equipment and the installation. Other protective measures, including open-PEN protection where relevant, surge protection and overcurrent protection, must be assessed rather than assumed from a product brochure.

The cable route should work for the house, not just the quotation

A neat route normally comes from spending time on it before work begins. We consider where the car is usually parked, whether the lead could cross a path, how the cable enters and leaves the building, what the finished fixings will look like and whether future changes are likely.

The shortest route is not always the best route. A slightly longer run may be worth it if it protects the building, avoids an awkward visual line or places the charger where it is safer and easier to use every day.

Smart charging should fit around real life

Private domestic and workplace charge points sold in Great Britain are subject to smart-charge-point requirements. In ordinary use, smart scheduling can move charging away from periods of higher demand or align it with a suitable tariff. The controls should be explained clearly, including what happens if the internet connection is unavailable.

Before choosing a charger, it is worth discussing the vehicle, expected mileage, parking routine, tariff, solar generation and whether more than one vehicle may need charging later. The best specification is the one that remains convenient after the novelty of the app has worn off.

What a considered quotation should explain

A quotation should make the proposed work understandable, including:

The aim is not simply to make the car charge on installation day. It is to leave a safe, documented installation that is straightforward to use and makes sense as part of the wider electrical system.

• The charge point and charging rate proposed.
• The new circuit, cable route and visible finishes.
• The protective devices and any load-management arrangement.
• Assumptions about the supply and any work dependent on further checks.
• Testing, electrical certification and Building Regulations notification where applicable.
• What is excluded, and what could reasonably alter the final scope.