Electric car charger types compared

The four tiers of charging

A three pin lead, often called a granny lead, draws around 2.3kW from an ordinary socket. It adds roughly eight miles of range an hour. It is a backup, not a plan, and it should never be run through an extension lead or a reel.

A dedicated home wall unit on a single phase supply delivers 7kW, adding around 25 to 30 miles an hour and filling almost any car overnight. This is what the overwhelming majority of UK homes install and it is the right answer for the overwhelming majority of drivers.

22kW AC requires a three phase supply, which very few houses have, and only benefits cars with a three phase onboard charger. Many cars cap AC charging at 7kW or 11kW regardless of what the unit can supply.

Rapid and ultra rapid DC chargers, from 50kW to 350kW, bypass the car's onboard charger entirely and feed the battery directly. These belong at service stations and retail parks, not at home.

• 3 pin lead: about 2.3kW, emergency use only
• Home wall unit: 7kW, overnight charging, the standard choice
• 22kW AC: needs three phase and a car that can accept it
• Rapid DC: 50kW and up, public network only

Connectors, in one paragraph

Every modern car sold in the UK uses Type 2 for AC charging, so any home unit made in the last several years is compatible. For rapid DC, CCS has effectively won, with CHAdeMO now limited mostly to older Nissan models. If you are choosing a home charger, connector compatibility is a non issue unless the car is genuinely old.

Tethered against untethered, and smart features

A tethered unit has the cable attached, which is quicker daily and tidier in use but fixes your cable length. An untethered unit has a socket and you bring your own cable, which looks neater on a front elevation and copes with any future car. Neither charges faster.

All new domestic chargers sold in Great Britain must meet smart charging requirements, so scheduling is standard rather than a premium feature. What varies is app quality, whether the unit supports solar surplus charging, whether it can do load management, and how the manufacturer behaves in year four when something fails.

• Tethered: fastest routine on a private driveway
• Untethered: tidier and more flexible for shared or street facing parking
• Load management protects the main fuse when the house draws heavily
• Solar diversion is worth it only if you have or plan panels

What decides which one you can have

Your supply decides the ceiling. A single phase 60A, 80A or 100A main fuse, an earthing arrangement that needs checking for an outdoor charge point, and whatever else the house draws at teatime all determine whether 7kW can be installed as is or needs load management. Three phase in a domestic property in the South Wales valleys is rare enough to treat as an exception.

Parking decides the rest. A charger must not create a trip hazard across a public footway, so on street parking generally rules out a domestic wall unit no matter how much you want one. Where that applies we will say so on the phone rather than take a booking we cannot fulfil.

What most drivers should actually buy

For a house with off street parking: a 7kW smart unit, tethered if the driveway is private and the car parks consistently, untethered if the unit will be seen from the street or the parking arrangement varies. Add load management where the supply is tight, and solar diversion only if panels exist or are planned.

Public rapid charging then becomes the occasional long journey tool rather than the default, which is where the running cost difference is largest. Charging overnight at home on an EV tariff typically costs a small fraction of rapid charging on the road.