Home EV charging in the UK: a practical starting guide

What actually happens when you plug in

A home AC chargepoint supplies electricity to the vehicle. The car’s onboard charger converts AC electricity into the DC energy stored in its battery. This is why the vehicle’s AC rating matters: the number printed on a wallbox is the power the equipment can offer, not a promise that every connected car will take that amount. Tesla’s explanation of onboard charging describes this distinction; exact capabilities must come from your own vehicle’s documentation.

Keep two units separate. Kilowatts, written kW, measure charging power. Kilowatt-hours, written kWh, measure energy. A 7kW input sustained for one hour represents 7kWh from the supply before allowing for losses. A 60kWh battery describes energy capacity, not the speed at which it can charge. Confusing these units makes both product comparisons and cost estimates unreliable.

References: Tesla UK — What an onboard charger does

Check the parking arrangement before shopping

Write down where the car will actually be parked, which side its charging port is on and whether the cable can reach without obstructing a route used by other people. A charger mounted near the front of a driveway may be inconvenient when a different vehicle parks there. Think about cable storage, opening doors, reversing in and whether another household car needs access.

If you rent, hold a lease or share parking, establish who can authorise work and who owns the relevant electrical supply. Ask an installer to assess the site rather than assuming a clear-looking wall makes the installation straightforward. The useful first outcome is a feasible location and an agreed permission process, not a shopping basket full of equipment.

What to ask an installer to assess

An installation quotation should explain what is included and which site conditions could change the work. Ask about the supply assessment, cable route, any work to the consumer unit, commissioning and documentation. This is a request for a professional survey, not a DIY electrical checklist. The Energy Saving Trust recommends using a registered chargepoint installer and explains that network registration is normally handled by the installer.

For comparison, give each installer the same information: parking photographs, the intended charger position, the vehicle and your expected charging routine. Ask for hardware and installation costs to be distinguished. A cheaper headline package may not include the same route length, groundwork or additional electrical work. Keep the written scope, exclusions and warranty arrangements with the quotation.

References: Energy Saving Trust — Charging electric vehicles

Choose features that solve a real problem

A tethered unit has a cable attached; an untethered unit uses a separate charging cable. Consider everyday convenience, cable reach and storage rather than treating either format as universally better. With smart features, ask exactly what the charger can schedule, what requires an internet connection and what remains usable if an app or connection is unavailable. Use our home charger selector to filter models by tethered preference and solar capability.

Great Britain’s smart chargepoint regulations (GOV.UK) cover smart functionality and cybersecurity standards for home units. Compliance is not the same as compatibility with a particular energy supplier’s tariff. Check those supplier conditions separately. If you are considering solar or load balancing, ask the installer and manufacturer to confirm the specific accessories and configuration needed; a feature name alone does not describe the complete installation.

References: GOV.UK — Electric vehicle smart charge point regulations

Work through an ordinary battery top-up

Consider a hypothetical car with 60kWh of usable capacity, arriving at 20% and charging to 80%. The battery gains 60 × (80 − 20) ÷ 100 = 36kWh. Assuming 90% charging efficiency, the grid supplies 36 ÷ 0.90 = 40kWh. At an illustrative £0.25 per kWh, that session costs £10. These are transparent example inputs, not a current electricity offer or a specification for a named vehicle.

If the available input power is 7.4kW, the same simplified model gives 40 ÷ 7.4 = about 5 hours 24 minutes. For an in-depth breakdown of charging speeds, read our guide on 7kW vs 22kW charging and see our home EV charging cost guide to see how different tariffs alter the cost.

Build a routine around the energy you need

A full-battery calculation can make a routine look more demanding than it is. If you only need to replace the energy used on a normal day, model that top-up instead. Your preferred charge target should follow your vehicle manufacturer’s advice and your next journey; this guide does not prescribe one universal daily percentage for every battery.

If a tariff rewards charging in a particular window, check whether your intended top-up fits inside it at your actual AC limit. Keep an allowance for a longer journey or an unexpectedly low arrival charge. A plan that works only when every assumption is perfect is less useful than one with some flexibility.

Your practical next steps

Collect the usable battery capacity, AC limit and a recent electricity bill. Calculate one normal top-up and one demanding example, such as arriving home low before an early departure. Compare the time estimates with when the car is parked. This gives you a clearer brief for an installer than simply requesting the highest available power.

Next, get an assessment of the property and confirm permissions. Compare the complete installation scope, then revisit the tariff using total household consumption. The cost calculator below starts with the energy question; its next-step button carries the same top-up into the charging-time tool so you do not have to enter the battery figures again.