Detached garages are often fed by a cable sized for light and a socket, run in a trench decades ago. A 7 kW charger at the garage needs about 32 amps plus whatever else is out there. If the feed is too small, the proper job is a new cable from the house, not a new breaker in the garage board. Earthing must also suit a car plugged in at the door. The surveyor should identify the feed size, length and earthing before anyone orders a wallbox to match the brickwork.
Check detached garage supplies for EV chargers before you accept a price
If a new trench is needed, coordinate it with patios and lawns you care about.
The price effect of detached garage supplies for EV chargers
A new buried feed can cost more than the charger. It is still cheaper than a failed circuit and a dug-up garage later.
A miss that shows up later: detached garage supplies for EV chargers
The mistake is a charger on the garage lighting circuit, or a commando adapter on the old socket.
Write detached garage supplies for EV chargers into the quote
The quote should say 'reuse feed' or 'new feed', with the cable size and who digs.
Detached garage supplies for EV chargers
Look for the garage isolator in the house and the cable leaving towards the garden. Do not guess the size from the trunking width.
- Old garage feeds are often too small
- New cable from the house is the honest fix
- Earthing must suit the car
- Do not use the lighting circuit
Frequently asked questions
Can the charger live inside with the door shut?
Only if the lead reaches the port without being crushed by the door. Many people mount outside beside the parking position.
What if the garage is timber?
Then the fixing and the cable route need a design that suits the structure. The supply question remains.
Is three-phase in the garage likely?
Only if someone put it there. Most domestic garages are single-phase.
Will a voltage drop calculation be needed?
Yes on a long garden. Ask to see that it was done.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local EV Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.