7kW vs 22kW EV Chargers: The Number You’ll Never Reach
22kW sounds three times better. But ~97% of UK homes can’t supply it — and most cars can’t accept it. Why 7kW is the correctly sized answer, with honest costs and times.
The short answer
Buy the 7kW charger. It’s the fastest a standard UK single-phase supply can run — and ~97% of UK homes are single-phase — adding 25–30 miles of range an hour, filling any current EV overnight (£800–£1,200 installed). The 22kW alternative fails three tests at once: it needs a three-phase supply almost no home has, the upgrade costs £1,500–£5,000+ (worst cases £15,000) plus a 4–10 week approval — and the least-advertised catch — most EVs’ onboard chargers cap AC charging at 7–11kW anyway, so the 22kW box charges your car at the car’s limit regardless. Money spent on a number you’ll never reach.
The details that actually matter: real charge times (a 60kWh EV does its daily 20–80% in 4–5 hours), the £500 grant rules (renters and flats yes, driveway homeowners no), cable sizes and fuse realities, and which 7kW charger to buy for your tariff and solar plans. All below.
What this guide covers
Charger shopping starts with a seductive number: 22kW, three times the power of the standard box, surely the future-proof choice. This guide exists to save you that money. The 7-vs-22 question has a settled answer in Britain, and it’s settled by physics, by the grid — and by a specification printed in your car’s manual that the charger adverts never mention.
The charging speeds ladder — where each rung lives
2.3kW — the three-pin plug: ~8 miles of range an hour; a 60kWh battery takes over 24 hours. Fine for emergencies, costly and slow as a routine. 7kW — the UK home standard: the single-phase maximum, 25–30 miles an hour, everything charges overnight. 11kW — three-phase territory: ~35–40 miles an hour, common in Europe and workplaces, rare in UK homes. 22kW — three-phase, fully used by few cars: ~90 miles an hour where the car accepts it — which is the whole story of this guide. 50kW+ DC rapid: the motorway-services tier; DC rapids are commercial infrastructure (£15,000+ a unit), not home equipment. Home charging is an AC world, and in Britain’s single-phase housing stock, AC means 7kW.
Why 7kW is the answer: costs, inclusions & the grant
A standard 7kW installation runs £800–£1,200 all-in (live market average ~£1,087; London and the South East 15–25% higher): the unit itself (£400–£700 — budget models from ~£450, premium solar-diverting units toward the top), labour, up to ~10m of cabling, protection, testing, certification, and the network notification your installer files. The honest cost-swings are all in the electrical work, not the box: a consumer-unit upgrade adds £300–£800, long cable runs £100–£300+, groundwork to a detached garage £200–£600 — which is why two legitimate quotes can be £1,000 apart, and why comparing a couple is worth the ten minutes. Every new home charger is a smart charger by law (the 2022 regulations), which is less bureaucracy than blessing: smart scheduling is what connects your charger to ~7p overnight tariffs, and six hours at 7kW is ~42kWh — the cheap window and the charger are sized for each other.
The 2026 grant: £500 — but not for driveway homeowners
The EV Chargepoint Grant was raised in April 2026 to 75% of costs, capped at £500 per socket (up from £350), running to 31 March 2027. Who qualifies: renters and flat owner-occupiers with off-street parking, landlords (up to 200 sockets a year), and a newer route for on-street parkers with approved cross-pavement solutions — claimed by your OZEV-approved installer, applied straight off the invoice. Who doesn’t: homeowners in houses with driveways, excluded since 2022. If that’s you, your subsidy is the tariff: overnight charging at ~7p versus 75p+ public rates saves a typical driver £1,000+ a year, paying the install back before the second MOT. (Scotland adds up to £300 via the Energy Saving Trust for eligible households.)
Why 22kW usually isn’t: the three stacked catches
Catch one: the supply. 22kW charging needs a three-phase electricity supply. Roughly 97% of UK homes are single-phase — three-phase is the stuff of workplaces, farms and some new-builds. Catch two: the upgrade. Getting three-phase to a single-phase house costs £1,500–£5,000 in typical cases and £15,000+ in bad ones, entirely at your network operator’s discretion and local infrastructure’s mercy — plus a formal G99 approval taking 4–10 weeks, where a 7kW install is a same-week notification. Catch three — the one the adverts skip: your car. An EV’s AC charging speed is set by its onboard charger, and most cap at 7kW or 11kW — only a handful of models (some Renaults historically, various 11kW Germans) go higher on AC. Plug a 7kW-limited car into a 22kW wallbox and it charges at 7kW, full stop. Stack the three and the verdict writes itself: 22kW at home is for the rare household that already has three-phase and a car that can use it — or for workplaces and fleets, where it belongs. Everyone else is buying a bigger number for the wall, not the battery.
Real charge times at 7kW (the table that ends the anxiety)
| Battery | Flat → full at 7kW | Daily 20–80% top-up |
|---|---|---|
| 40kWh (city EV) | ~6 hours | ~3.5 hours |
| 60kWh (family EV) | ~9 hours | ~4–5 hours |
| 77kWh (large EV/SUV) | ~11 hours | ~6 hours |
The pattern: everything fits between dinner and breakfast, and the daily reality — a 20–80% top-up — fits inside the overnight cheap window with room to spare. This is the practical death of the 22kW argument: when the car is full at 3am either way, tripling the power improves nothing you’ll ever notice. The rule of thumb for any car: battery kWh ÷ 7 ≈ full-charge hours, and you’ll rarely need the full number.
Cables, fuses & the practical details installers handle
Cable size — the surprisingly popular question: a 7kW charger draws 32A continuously, which typically means 6mm² cable on short runs and 10mm² on longer ones — but the exact size is your installer’s calculation (run length, routing method, voltage drop), not a shopping decision. Your main fuse matters: houses carry 60A, 80A or 100A fuses, and a 32A charger running alongside a shower and oven can crowd a smaller one — the standard answer is CT-clamp load management, built into virtually every modern smart charger, throttling the car automatically when the house is busy. Paperwork: the install is notifiable electrical work with certification, and your installer files the DNO notification (allow 2–10 working days’ lead). Tethered vs untethered: tethered (cable attached) wins for daily convenience; untethered (socket only) is neater and car-agnostic. None of this is DIY territory — but a quote that itemises cable sizing, load management and certification is how you recognise an installer doing it right.
Which 7kW charger? Three axes, then our reviews
Every 7kW charger delivers the identical 7kW — the price differences buy software, looks and integrations. So choose on three axes. Tariff: heading for Intelligent Octopus Go or similar? Start from our compatible chargers list (Ohme for the deepest integration — or check whether your car qualifies directly, freeing you to buy anything). Solar: panels on the roof or in the plans? The myenergi Zappi remains the solar-diversion benchmark, and its wider ecosystem runs charger, battery and diverter from one app. Budget: the Sync EV Wall Charger 2 — also sold as the British Gas charger at ~£400 in bundles — is the value benchmark, with Indra and Pod Point close behind. Pick the ecosystem, not the wattage: the wattage is settled.
Frequently asked questions
What is a 7kW charger and why is it the standard?
The fastest charger a single-phase supply runs (32A) — and ~97% of UK homes are single-phase. 25–30 miles of range an hour, any EV full overnight, six cheap-rate hours ≈ 42kWh. Smart by law since 2022, installed with a simple network notification.
How much does one cost installed?
£800–£1,200 typical (average ~£1,087; London/SE +15–25%): unit, labour, ~10m cabling, certification and DNO notification. Consumer-unit upgrades (£300–£800) and long runs are the honest cost-swings — get a couple of quotes.
7kW vs 22kW — the real difference?
22kW is 3× the power on paper, but needs three-phase supply (~3% of homes), a £1,500–£15,000 upgrade with 4–10 weeks’ approval — and most cars cap AC charging at 7–11kW anyway, so the wallbox charges at the car’s limit. At home, it’s usually money spent on a number you’ll never reach.
How long to charge at 7kW?
Battery kWh ÷ 7 ≈ hours: 40kWh ~6h, 60kWh ~9h (daily 20–80% just 4–5h), 77kWh ~11h. Everything fits overnight — which is why extra speed at home changes nothing you’d notice.
What cable size does it need?
32A continuous — typically 6mm² short runs, 10mm² longer, calculated by your installer per run and method. Main fuse (60/80/100A) matters; CT-clamp load management in modern chargers handles busy-house moments automatically.
Which 7kW charger should I buy?
All deliver identical speed — pick by ecosystem: tariff compatibility (Ohme, or check your car’s direct integration), solar diversion (Zappi), or budget (Sync/British Gas ~£400). Tethered for convenience, untethered for flexibility.
7kW is the right size — 22kW is a number for the wall
The bottom line: Buy 7kW: it’s the single-phase maximum ~97% of UK homes live with, it fills any EV overnight for £800–£1,200 installed, and it’s sized perfectly for the cheap-tariff window. 22kW fails three tests — the supply you don’t have, the £1,500–£15,000 upgrade, and the 7–11kW cap in your car’s own manual. Spend the difference on the right ecosystem instead: tariff integration, solar diversion, or the £400 value pick.
Get my free quotes →The verdict
The 7-vs-22 question is that rare consumer dilemma with a genuinely settled answer: in single-phase Britain, with cars that cap their own AC intake, 7kW isn’t the budget option — it’s the engineered-correct one. The industry knows it, which is why every serious home charger on the market is a 7kW unit, and why the 22kW premium survives mostly on the instinct that bigger numbers must be better. Your car’s manual disagrees, and it wins.
Where the real choices live: the ecosystem (tariff integration, solar diversion, or honest value — our compatible-chargers guide and reviews map it), the tariff (a 7kW charger on a ~7p overnight rate is the whole financial case), and increasingly the solar question — because a driveway that charges the car from the roof in summer is the endgame of home energy. A couple of free, no-obligation quotes from MCS-certified installers will price that full picture for your home.
Important
Going Solar UK is an introduction service, not an installer or electrical adviser. This guide is general 2026 information, not professional advice: installation costs, grant rules and eligibility change (verify current schemes on gov.uk), charging speeds depend on your specific vehicle’s onboard charger, and all electrical work must be carried out and certified by qualified installers. Figures are typical estimates, not guarantees.
We may receive a commission when we introduce you to an installer, at no cost to you. Any contract for work is directly between you and the installer.