If you buy an electric car, home charging is where you save the most money and time. Installing a charger properly, however, is an electrical engineering job, not a plug-and-play gadget. This guide covers what to plan for in India, the UK and the US.
Charging levels at a glance
| Type | Typical power | Adds roughly | Where |
|---|---|---|---|
| Normal socket (portable cable) | About 2 to 3 kW | 10 to 20 km per hour | Occasional or overnight top-ups |
| Home wallbox, single-phase | 7 to 7.4 kW | 35 to 50 km per hour | Most homes in India and the UK; US Level 2 is similar or higher |
| Three-phase wallbox | 11 to 22 kW | 60 km per hour or more | Homes with three-phase supply, if the car supports it |
| Public DC fast charger | 50 to 350 kW | Hundreds of km per hour | Highways and city hubs |
Most electric cars take AC power at up to 7 to 11 kW at home. Paying for a 22 kW charger only helps if your car can accept it.
Step 1: check your supply
- Sanctioned load. In India, a 7.4 kW charger often requires increasing the sanctioned load with your electricity distribution company. Running above it can lead to penalties.
- Main fuse and meter. In the UK, the installer checks whether the main fuse can handle the extra load, and may fit a load-management device.
- Panel capacity. In the US, an electrician checks the main panel rating and whether a 240 V circuit can be added.
Step 2: a dedicated circuit
A charger must have its own circuit with correctly sized cable and its own protection. A 7.4 kW charger on 230 V draws about 32 amps continuously for hours, far more than a normal socket circuit is designed for. Undersized wiring overheats over time and is a fire risk.
Try it: enter 230 volts and 32 amps above to see why a charger is equivalent to running several heaters at once.
Step 3: safety protection
- Earth leakage protection. A residual current device protects against electric shock. EV chargers need a type that can detect the DC leakage currents electric vehicles can produce, either built into the charger or fitted separately.
- Proper earthing. A good earth connection is essential, and outdoor installations sometimes need special earthing arrangements.
- Weatherproofing. Outdoor chargers need a suitable weather rating and protected cable routes.
Step 4: smart features worth paying for
- Scheduling, so you can charge on cheaper night tariffs where available.
- Load balancing, which slows charging when the rest of the house is using a lot of power.
- Solar matching, which charges from surplus rooftop solar. See our rooftop solar guide.
Costs
Many car makers include a basic wallbox and installation, or offer it as a package. Otherwise, costs depend on the charger, cable run length and any supply upgrades. Get at least two quotes from licensed electricians and ask them to include the earthing, protection and any load enhancement charges.
Work out what you will save each month with our EV vs petrol cost calculator.
Frequently asked questions
Can I just use a normal 15 A socket?
For occasional charging with the car maker's portable cable, usually yes, if the socket and wiring are in good condition. For daily use, a dedicated wallbox is safer and faster.
Can I install a charger in an apartment parking space?
Usually yes, with permission from the housing society or building management and a supply from your own meter or a shared metered system.