7kW vs 22kW vs Rapid: Which EV Charger?

Choosing the wrong charger power is the most expensive mistake in a commercial EV project. Over-spec and you pay for capacity that sits idle — and often trigger a grid connection you never needed. Under-spec and you throttle a busy fleet yard. The right answer almost never comes from the charger spec sheet. It comes from one question: how long does each vehicle actually sit on the bay?

This guide walks through the three tiers — 7kW AC, 22kW AC and DC rapid — by dwell time, electrical supply and cost, using verified July 2026 figures.

The one rule: match power to dwell time

A charger only needs to add the miles a vehicle will use before it leaves. If a car parks for eight hours, a 7kW charger delivers roughly 240 miles of range in that window — far more than almost anyone drives in a day. Adding more power buys you nothing because the vehicle is asleep on the bay anyway.

Rapid chargers exist for the opposite case: a van on a delivery round, a taxi between fares, or a customer grabbing 20 minutes of charge. Short dwell, high power. Everything else is a mismatch between how fast you’re pushing electrons and how long the vehicle is there to receive them.

Setting	Typical dwell	Sensible tier
Staff car park	6–9 hours	7kW AC
Visitor / customer bays	1–3 hours	7kW or 22kW AC
Shared bays, high turnover	30–90 mins	22kW AC
Van / HGV depot, quick turnaround	15–45 mins	DC rapid
Public / paid forecourt	10–30 mins	DC rapid

More on picking a tier by scenario on our charger types page.

7kW AC — the workplace default

A single-phase 7kW charger is the workhorse of UK workplace charging. It adds around 25–30 miles of range per hour — comfortably enough for any vehicle parked for a working day. It runs off a standard supply, needs no special grid approval in most cases, and is cheap to install.

Cost: £800–£1,500 per bay. For staff and visitor parking where cars sit for hours, this is almost always the correct choice. Fit more 7kW sockets rather than fewer fast ones — coverage beats speed when everyone is parked anyway.

22kW AC — often oversized, and here’s why

This is where most businesses overspend. A 22kW charger costs £2,500–£4,500 per bay — two to three times a 7kW unit — and the pitch is “three times faster.” In practice it usually isn’t.

The catch is the car, not the charger. Most EVs cap their onboard AC charger at 7kW or 11kW. Plug a typical car into a 22kW unit and it still only pulls 7–11kW — you’ve paid for 22kW and the vehicle throttles it back. Only a minority of models (some Renault, Smart and a few others) actually accept the full 22kW on AC.

22kW does earn its place in a specific situation: shared bays with genuine turnover, where an 11kW-capable vehicle rolls off after 90 minutes and the next one rolls on. There the extra headroom serves the queue, not the individual car. But 22kW also draws far more from your supply per socket, which is what pushes projects toward a costly grid reinforcement — see load management below. If your bays are dedicated or dwell is long, 22kW is money spent on a number, not a benefit.

DC rapid (50kW+) — for fleets and forecourts

Rapid chargers convert to DC and bypass the car’s onboard limit, delivering 50kW and up — often 80% in 30–45 minutes. This is the right tool for van, HGV and coach depots on tight turnarounds, taxi ranks, and any public or paid charging.

Cost: £25,000–£45,000 for a 50kW unit, before groundworks and any grid upgrade. That’s an order of magnitude above AC, so rapid only pays off where short dwell genuinely requires it. Putting a rapid charger on a staff car park is pouring money into a bay that a £1,000 unit would serve just as well.

For depots, the economics elsewhere are compelling: depot charging runs at around 7p per mile against roughly 22p for diesel. The fuel saving, not the charge speed, is what makes the case.

Full breakdowns are on our cost guide.

Supply is the real constraint — dynamic load management

Charger power multiplies across every socket. Ten 22kW bays theoretically demand 220kW — often more than a site’s spare capacity, which triggers a Distribution Network Operator (DNO) reinforcement. Since 1 April 2023 there is no reinforcement charge, but the lead time remains: a DNO connection quote takes 5–65 working days, and three-phase or high-load installs need G99 approval before works begin.

Dynamic load management is how you avoid this. It monitors your building’s live demand and shares the spare capacity across chargers in real time — throttling bays when the kitchen and HVAC are running, ramping them up overnight. This lets you fit far more sockets on the same supply and frequently sidesteps a DNO reinforcement altogether. It also quietly reinforces the case for 7kW: lower per-socket draw means more bays before you hit the ceiling. Details on our load management page.

Grants and tax — the 2026 position

The funding landscape has shifted, and stale advice online is now wrong. The current, verified position:

• Workplace Charging Scheme (WCS): up to £500 per socket — this rose from £350 on 1 April 2026 — covering 75% of cost, up to 40 sockets, running to 31 March 2027. If you’ve seen “£350,” it’s out of date.
• Depot Charging Scheme: 70% of cost up to £1 million for van, HGV and coach depots.
• 100% First-Year Allowance on chargepoints, to 31 March 2027 (Corporation Tax) / 5 April 2027 (Income Tax) — the full cost written off against taxable profit in year one.
• The old Staff & Fleets grant has closed — don’t budget around it.

On the people side:

• Staff charging their own EV at the workplace is Benefit-in-Kind exempt (s237A ITEPA) — no tax charge on the employee.
• Company-car EV BiK is 4% in 2026/27 — low, but no longer the old 2%. Quoting 2% understates the cost to a driver.

Full detail and eligibility on grants and funding. Whether the numbers stack up for your site is covered in is workplace EV charging worth it.

One compliance note: Building Regs Part S

If you’re constructing a new non-residential building with more than 10 parking spaces, Part S requires at least one chargepoint plus ducting (cable routes) to at least one in five of the remaining spaces. Retrofitting ducting later costs many times more than laying it during the build, so factor it in early. Separately, if you’ll offer public or paid charging, the Public Charge Point Regulations 2023 apply — covering reliability, pricing transparency and contactless payment.

The decision, in one line

Start from dwell time, then check your supply:

• Long dwell (staff, visitors) → 7kW AC. Fit more of them.
• Shared, high-turnover AC bays with 11kW+ cars → 22kW AC, otherwise skip it.
• Short-dwell fleet, depot or public → DC rapid.
• Any multi-socket site → design in dynamic load management before you assume you need a grid upgrade.

Get these four right and you avoid the two classic failures: paying for 22kW the cars can’t use, and triggering a DNO reinforcement you could have engineered around.

Want a specification matched to how your vehicles actually park — not a generic quote? Request a quote and we’ll size it to your dwell times, supply and budget.