The short answer
For the vast majority of UK homeowners, a 7 kW charger is the right choice: it charges overnight on a standard single-phase supply and costs less to install. A 22 kW unit only adds value if you have three-phase supply and a car whose on-board charger accepts 22 kW AC — relatively uncommon in typical UK homes. See the full speed comparison and supply capacity guide.
When requesting EV charger quotes, some homeowners ask whether to go straight to a 22 kW unit for maximum future-proofing. The practical answer is almost always 7 kW — not because 22 kW is bad, but because most UK homes do not have three-phase supply and most UK cars have on-board AC chargers limited to 7 kW or 11 kW anyway. This guide cuts through the confusion with the questions that actually determine the right speed for your home.
7 kW vs 22 kW at a glance
- 7 kW supply needed Single-phase 32 A — standard in UK homes
- 22 kW supply needed Three-phase 32 A — rare in domestic UK properties
- Car acceptance limit Many EVs cap AC charging at 7 kW or 11 kW
- Overnight charge (60 kWh EV) 7 kW: ~9 hours — 22 kW: ~3 hours
- Installation cost difference 22 kW typically £500–£2,000+ more (supply upgrade)
- Recommendation for most homes 7 kW smart wall box
The two questions that decide it
Before comparing 7 kW and 22 kW chargers, two factual checks determine whether 22 kW is even possible at your property:
- Do you have three-phase supply? A 22 kW AC charger requires three-phase electricity (three live conductors, approximately 400 V line-to-line). Most UK domestic properties are single-phase only. You can check by looking at your incoming supply tails at the consumer unit: three-phase has four conductors (three live plus neutral); single-phase has two (live and neutral). An electrician can confirm in seconds.
- Can your car accept more than 7 kW AC? The charge point speed only matters up to the limit of the car’s on-board AC charger. Many popular EVs — including most Nissan Leafs, many base-spec Tesla Model 3s and numerous others — have a maximum AC on-board charger of 7 kW or 11 kW. A 22 kW wall box will charge these cars at the car’s maximum, not at 22 kW. Check your car’s specification sheet under “AC charging speed”.
If the answer to either question is no, the 7 kW vs 22 kW debate is already settled: 7 kW is the right choice.
| Scenario | Right choice | Reason |
|---|---|---|
| Single-phase supply + car max 7 kW | 7 kW | 22 kW impossible and unnecessary |
| Single-phase supply + car accepts 11 kW | 7 kW | 22 kW impossible without supply upgrade |
| Three-phase supply + car max 7 kW | 7 kW | Car bottleneck — 22 kW provides no benefit |
| Three-phase supply + car accepts 22 kW | 22 kW possible | Could benefit if car is frequently depleted |
When 7 kW is more than enough
Consider typical usage: most UK drivers cover 25–35 miles per day. A 7 kW charger replaces that range in approximately one hour. Even starting with a nearly flat battery after a long trip, a 7 kW charger refills a 60 kWh battery overnight. The “I might occasionally need it full first thing” scenario is the smart charger’s job — schedule charging to start at midnight and finish before your departure time. See home charging costs to understand how overnight scheduling cuts bills further. This page provides general information; an OZEV-approved installer can assess your three-phase supply status and car specification during a site visit.
Confirm the right speed for your home
An OZEV-approved installer can check your supply type and car specification, recommend the right unit and apply the £350 grant. Get quotes now — free to enquire, no obligation.
Frequently asked questions
Is a 22 kW home EV charger worth it?
Only if you have three-phase supply and a car whose on-board AC charger accepts 22 kW. For most UK homeowners, 7 kW on a single-phase supply charges overnight and is far cheaper to install.
Do I have three-phase electricity at home?
Most UK domestic properties are single-phase only. Check your consumer unit for four supply conductors, or ask an electrician — they can confirm in moments at a site visit.
Can I future-proof by installing a 22 kW charger now?
Only if you already have three-phase. Installing a larger unit without the required supply provides no benefit — the charge point will deliver only as much power as the supply allows.
What is the maximum AC charging speed of most EVs?
It varies by model and variant. Common limits are 7 kW, 11 kW and 22 kW. Check your car’s specification sheet or owner’s manual under “AC on-board charger” or “AC charging speed”.
Sources & further reading
- OZEV (Office for Zero Emission Vehicles) — Chargepoint grant eligibility and home installation guidance
- Energy Saving Trust — Home EV charging speeds, overnight charging and tariff guidance
- IET Wiring Regulations (BS 7671) — Three-phase supply requirements for 22 kW charge points
- GOV.UK — EV chargepoint regulations and supply upgrade guidance
This is general information about home EV charging in the UK, not electrical, planning or installation advice for your specific property. Costs, timescales and specifications vary with your home’s supply, parking arrangement and chosen installer. Always obtain written quotes from OZEV-approved installers and check grant eligibility at GOV.UK before committing.