"I want the fastest charger you can fit." I hear it weekly. Then I check the property's electrical supply and have to explain why the £1,500 22kW unit they're looking at is going to charge their car at 7kW anyway. Here's the actual maths.
Single-Phase vs Three-Phase Supply
UK domestic properties are almost universally single-phase. That gives you a maximum of 100A at 230V — about 23kW theoretical, but realistically 7-7.4kW for a charger after accounting for the rest of the house's normal load.
22kW chargers require three-phase supply (3 separate live wires from the grid). Three-phase is standard in commercial properties and very rare in UK homes. Upgrading from single-phase to three-phase costs £3,000-£10,000+ depending on how far the supply has to be brought, plus several months of UK Power Networks paperwork. For a home install it almost never makes sense.
Even If You Could Run 22kW — Most Cars Can't Take It
Even on a true 22kW supply, the bottleneck is usually the car. The on-board AC charger in most EVs is rated 7kW or 11kW. A Tesla Model Y, BMW i4, Audi e-tron, Volkswagen ID.3 — all 11kW max on AC. A Renault Zoe is the rare exception (22kW capable).
So even with a 22kW wall charger and 22kW supply, your Tesla would charge at 11kW max. You're paying double for hardware your car ignores.
When 7kW Is More Than Enough
7kW gives you about 25-30 miles of range per hour of charging. Plug in at 7pm, full battery by midnight on a typical 60kWh EV. Most UK drivers do less than 30 miles a day; you're replacing what you used overnight on a cheap rate, not refilling from empty.
For 99% of home use cases — daily commute, weekend errands, an occasional longer trip — 7kW is genuinely all you need.
When 22kW Actually Makes Sense
Three legitimate use cases:
1) You have three-phase supply already (rare in domestic, common in light commercial / agricultural properties).
2) You drive a Renault Zoe or similar 22kW-capable EV AND you regularly do 200+ miles a day with short turnaround.
3) You're installing in a small fleet / shared parking setup where multiple cars share one charger and need quick top-ups during the day.
For everyone else: 7kW.
What I'd Actually Install
For a typical Pinner / Hemel customer with one or two EVs and standard single-phase supply: a single 7.4kW charger. £999-£1,200 fitted depending on which unit.
If you genuinely need faster charging and have three-phase: I install 22kW chargers, typically Zappi 22kW or Hypervolt 22kW. Add £400-£600 to the unit cost, plus the supply costs if three-phase isn't already there.
Use the EV calculator on the pricing page or call 07405 629 940 to talk through what makes sense for your specific car and supply.