7kW vs 22kW home EV chargers

Faster sounds better, but charging speed has three limits and you only get the lowest of them: your home’s supply, the charger, and the car. The supply is the costly one to change; the charger is the cheap part.

Single-phase and three-phase, in plain terms

The UK grid is three-phase, but a typical house takes one of the three live wires. Which? puts it as “most UK dwellings are attached to only one of those three live wires”. That is a single-phase supply. A three-phase supply has all three, and it is what allows 11kW and 22kW chargers to work at full power.

A single-phase home charger tops out at 32A at 230V, which is 7.4kW (computed). Mainstream models in our data are rated 7.4kW, with the Andersen A3 and EO Mini Pro 3 at 7.2kW. A charger sold as “22kW” on a single-phase supply gives the same 7.4kW, so it saves nothing.

On three-phase, the maths changes. Wallbox’s Pulsar Max comes as 7.4kW (32A single-phase), 11kW (16A three-phase) and 22kW (32A three-phase). Tesla says its Wall Connector delivers 7.4kW on single-phase and up to 22.1kW on three-phase, vehicle permitting. So an “11kW” charger is a three-phase charger too.

Your car is the limit

Which? says it is “likely your car will have a maximum AC charging rate of 7kW to 11kW (or less, for plug-in hybrids)”, and that “very few cars can actually use” 22kW. If the onboard charger caps at 7.4kW, a 22kW wallbox charges it at 7.4kW. Check your car’s handbook or the maker’s specification for its AC charging rate before paying for more.

For a sense of scale, here is how long it takes to add 50kWh, a large top-up, at each power. These are simple division, ignoring charging losses, so real sessions run a little longer.

Which? publishes real figures for a 2022 Tesla Model Y: 38.5 hours on a 2.4kW three-pin plug, 24.5 hours on a 3.6kW charger and 12 hours on a 7kW charger.

How much speed do you actually need?

Overnight, a lot less than the marketing suggests. A six-hour cheap-rate window at 7.4kW adds about 44kWh (computed), roughly 148 miles at the EV Database average of 0.301kWh a mile. The DfT puts average battery-electric car mileage in England at 9,400 miles in 2025, which is about 26 miles a day or 7.8kWh (computed). A 7.4kW charger replenishes that in about 63 minutes. A 22kW charger would take about 21 minutes, a saving of 42 minutes on a night when the car is plugged in for hours anyway.

Where more power genuinely helps is in unusual use: a car with a very large battery on a high-mileage job, back-to-back charging of two vehicles, or a short stopover. For the average household it buys convenience you will not notice.

3.6kW or 7kW?

If you are weighing 3.6kW against 7kW, take 7kW: Which? lists 12 hours against 24.5 hours for the same car. A 3.6kW home charger is mostly a legacy product. Pod’s current Solo 3S page offers 7.4kW only, though its older Solo ranges included 3.6kW versions.

Some chargers can be set to a lower current if your supply is tight. Hypervolt can be permanently derated with internal DIP switches, and Easee adjusts fully dynamically between 6A and 32A. Ask about that, or about dynamic load balancing with a CT clamp, before buying a slower charger. The Energy Networks Association also allows a charger on a home with more than 60A existing demand if it is installed with a fail-safe load-limiting scheme that keeps total demand at 60A or below.

What a 22kW install needs and costs

You need a three-phase supply at the property. If you do not have one, upgrading is a job for your network operator (DNO), and the customer pays. The published figures vary widely:

• SP Electricity North West publishes an average of £5,370 for an upgrade to three-phase 80A per phase;
• installers told Citizens Advice £2,000 to £5,000, “with some quotes reaching much higher”; and
• MyBuilder says £1,500 to £3,500 through your DNO.

Our data folds this into a range of £1,500–£5,370. DESNZ confirms that all DNOs offer a three-phase upgrade only on a reactive basis, with the consumer responsible for the cost, and Octopus’s installation terms exclude any three-phase connection. We found no published timescale. Compare that with the standard network work for a 7kW charger, which is normally free (see our installation guide).

The hardware premium is small. myenergi sells the zappi at 7kW untethered and 22kW untethered, and the 22kW version costs about 7% more (computed from the prices on its page). The expensive part is the supply.

Charger choice is limited too. In our data, the models that come in 22kW three-phase form are the myenergi zappi, Wallbox Pulsar Max, Tesla Wall Connector and Zaptec Go 2, plus the EO Mini Pro 3, whose maker is in administration. The Ohme Home Pro and ePod, Hypervolt, Pod, Easee One (Easee sells separate 22kW models), Andersen A3 and Indra Smart PRO are single-phase only in the UK. See the zappi, the Wallbox Pulsar Max and the Zaptec Go 2 for details.

One earthing point if you do have three-phase. The wiring regulations treat a balanced three-phase installation differently from a single-phase one for open-PEN protection, and the IET warns that single-phase PEN protection devices should not be used for single-phase charging equipment in a three-phase installation. Your installer has to match the protection to your supply; see our PEN fault and earthing guide.

When 22kW makes sense

A 22kW charger, or more often an 11kW one, makes sense in a narrow set of cases:

• you already have a three-phase supply, so the premium is small;
• your car accepts 11kW or 22kW on AC, which is rare for the second figure;
• you do high mileage or charge several cars between short stops; or
• you are already paying for a three-phase upgrade for other reasons, such as a heat pump or workshop.

If you have three-phase and an 11kW car, an 11kW charger gives you most of the benefit and still leaves room on the supply. Otherwise, choose a good 7kW smart charger and spend the money on a smart tariff. Our best home EV chargers roundup compares the 7kW options.