3kW vs 7kW vs 22kW: How to Choose the Right Home EV Charger

For most UK homeowners, the answer is a 7kW smart charger and the choice of 3kW or 22kW suits a much narrower set of circumstances than most people realise when they start researching. A 7kW charger is the recommended standard for most households, adding 25–30 miles of range per hour and fully charging a typical 60kWh battery in 8–10 hours overnight. A 3kW unit takes roughly double that time and is increasingly considered inadequate for modern EVs with larger batteries. A 22kW unit charges three times faster than a 7kW but requires three-phase electrical supply which 97% of UK homes do not have, and upgrading to which costs £3,000–£15,000 depending on the DNO and distance. Here is the full breakdown of what each option delivers, what your home can actually support, and how to make the right decision for your specific situation.

Understanding What Power Output Actually Means

Before comparing the three options, it helps to understand what the kilowatt (kW) figure on a charger actually tells you and what it does not.

The kW rating on a charger is the maximum power it can deliver. Whether your EV actually charges at that rate depends on two additional factors: your home’s electrical supply, and your vehicle’s onboard charger (OBC) capacity.

Your home’s electrical supply determines the maximum power available. 97% of UK homes have single-phase power, which limits charging to a maximum of 7.4kW. Three-phase supply available in some rural and larger properties supports up to 22kW.

Your vehicle’s onboard charger is the component inside the car that converts AC power from your charger into DC power for the battery. The OBC has its own maximum rate. If your car’s OBC is rated at 7.4kW, installing a 22kW charger at home will not make it charge any faster the car will simply draw what its OBC can handle, regardless of what the charger is capable of delivering.

This means the right charger is determined by the lowest of three figures: your charger’s output, your supply’s capacity, and your vehicle’s OBC rate. Identifying all three before making a decision avoids buying a charger that is either more than your home can support or more than your car can use.

3kW Home EV Chargers

What they are

A 3kW charger (more precisely, 3.6–3.7kW) runs on a standard 13A single-phase supply the same supply as a domestic plug socket. In fact, many 3kW home chargers are essentially a more robust, weatherproofed version of a three-pin plug (“granny charger”) solution, though dedicated wall-mounted 3kW units are also available.

What they deliver

3.6–3.7kW chargers add 12–15 miles of range per hour. For a 60kWh battery depleted from empty, a full charge takes approximately 16–18 hours.

Who they suit

If you drive under 30 miles daily, a 3kW charger works fine. Plugging in at home every evening for 8–10 hours replenishes 96–120 miles of range sufficient for most low-mileage drivers who consistently top up rather than running the battery low.

They also suit:

• Plug-in hybrid (PHEV) drivers, whose battery capacities are smaller (8–18kWh typically) and fully charge overnight on a 3kW unit without issue
• Properties where consumer unit capacity is limited and a new dedicated circuit is not feasible
• Temporary installations where a full wallbox is planned later

The honest limitation

3kW chargers are increasingly outdated for full EVs, taking 18–20 hours to fully charge modern EVs with larger batteries. A 77kWh battery the size fitted to many current EVs takes over 20 hours to charge from near-empty on a 3kW unit. For anyone planning to regularly deplete the battery significantly, this creates a genuine range recovery problem.

A 3kW charger is also not eligible for the OZEV EV Chargepoint Grant in most configurations the grant is designed for smart, dedicated charging units rather than plug-based solutions.

7kW Home EV Chargers

What they are

A 7kW charger (technically 7.2–7.4kW) runs on a single-phase 32A circuit a dedicated circuit from the consumer unit, not a standard socket. This is the standard home EV charging solution in the UK. It is what OZEV grant applications are built around, what smart tariff integration is designed for, and what the vast majority of UK home installations involve.

What they deliver

A standard 7kW charger fully charges a typical 60kWh battery in 8–10 hours from empty. Most drivers charge overnight and rarely deplete batteries completely, meaning real-world charging takes 4–6 hours.

In miles of range per hour: approximately 25–30 miles, depending on the vehicle.

Who they suit

A 7kW charger is the most practical choice for most UK homes, providing full overnight charging without requiring electrical upgrades.

Specifically, 7kW suits:

• Any driver doing up to 200+ miles per day who charges overnight
• Homes with single-phase electrical supply (the majority of UK properties)
• Anyone wanting grant eligibility the OZEV EV Chargepoint Grant applies to smart 7kW units
• Anyone with solar panels wanting smart divert capability
• Anyone on a time-of-use electricity tariff (Octopus Intelligent, Economy 7, OVO Drive Anytime) wanting overnight off-peak scheduling

One important caveat

The 7kW the charger delivers is only fully used if your vehicle’s OBC is rated at 7kW or above. A growing number of EVs have 7.4kW OBC ratings but some older or more budget-oriented models have OBCs capped at 3.6kW or 6.6kW. If your car’s OBC is 6.6kW, a 7kW charger will charge it at 6.6kW, still significantly faster than a 3kW unit, but not the full 7kW. Check your vehicle’s OBC rate in the handbook or the manufacturer’s specification sheet before choosing.

22kW Home EV Chargers

What they are

A 22kW charger operates on three-phase power at 32A per phase. It charges approximately three times faster than a 7kW unit and is the fastest AC home charger available.

What they deliver

22kW chargers add 70–80 miles of range per hour. A 60kWh battery charges from empty in roughly 3 hours; a 100kWh battery in approximately 5 hours.

Why most UK homes cannot use one

97% of UK homes have single-phase power. Upgrading to three-phase costs £3,000–£15,000 depending on your DNO and distance, and is not always available in areas where the local grid has capacity constraints, the DNO may decline the application entirely.

Your EV must also support 22kW AC charging to benefit many vehicles are capped at 7–11kW even if they appear compatible. Common vehicles that do support 22kW AC include the Renault Zoe and Porsche Taycan. Most mainstream EVs including the Tesla Model 3, Volkswagen ID.4, Hyundai IONIQ 5, and Kia EV6 are limited to 11kW or 7.4kW AC regardless of the charger they are connected to.

When a 22kW home charger genuinely makes sense

You already have three-phase supply (some rural and larger properties do), you own a 22kW-capable EV, you need fast turnaround such as multiple daily trips, or you plan to add solar panels and want maximum self-consumption.

If none of these apply and for most UK homeowners they do not a 22kW home installation is a significant additional expense for a charging rate your home cannot support or your vehicle cannot use.

Side-by-Side Comparison

Feature	3kW	7kW	22kW
Miles of range added per hour	12–15	25–30	70–80
Time to charge 60kWh from empty	16–18 hours	8–10 hours	~3 hours
Electrical supply required	Single-phase 13A	Single-phase 32A	Three-phase 32A
Available in most UK homes	Yes	Yes	No (97% of homes need upgrade)
OZEV grant eligible	No (plug-based)	Yes	Rarely check current eligibility
Vehicle compatibility	All EVs and PHEVs	All EVs and PHEVs	Only 22kW-capable EVs
Smart charging / app control	Limited	Standard on modern units	Standard on modern units
Typical installation cost	£300–£600	£750–£1,350	£2,500–£5,000+
Best suited for	Low-mileage / PHEV	Most UK homeowners	Three-phase homes with compatible vehicles

What About 11kW Home Chargers?

You may have seen 11kW units mentioned and wondered where they fit. An 11kW charger is a three-phase unit running at a lower amperage per phase than a 22kW unit. It charges approximately 1.5 times faster than a 7kW unit, requires three-phase supply, and suits vehicles with 11kW OBC ratings which includes a larger number of EVs than those capable of 22kW.

For homes that do already have three-phase supply and have an EV with an 11kW OBC, an 11kW unit can be a sensible middle ground. For homes without three-phase, the same supply upgrade costs apply as for 22kW.

Can I Install Two 7kW Chargers at Home?

Yes, with an important condition. Two 7kW chargers running simultaneously draw 64A on a single-phase supply. Most domestic consumer units are rated at 60–100A for the whole property. Adding 64A of EV charging load on top of the household’s existing demand requires careful load assessment and typically a consumer unit upgrade or a load management solution.

The practical solution for most two-EV households is a dual-charger installation with a dynamic load management system one that monitors the property’s total electricity demand and shares the available capacity between the two chargers intelligently, rather than both drawing full power simultaneously. This avoids the need for an expensive supply upgrade while still providing effective charging for two vehicles.

This is exactly the kind of installation where a site survey matters the right solution is specific to your consumer unit, your supply capacity, and how you use both vehicles. Contact us for a site survey and we will specify what is actually needed rather than what is simply the most expensive option.

Tethered vs Untethered: The Other Decision

Once you have settled on the right power output, the other practical decision is whether to choose a tethered or untethered unit.

Tethered chargers have a fixed cable permanently attached to the unit. You pick up the cable and plug it straight into the car no separate cable needed, faster to use, and nothing to lose or forget. The downside is that the fixed cable suits a specific connector type typically Type 2 for most UK EVs so if you later change vehicles, you may need a new unit.

Untethered (socket) chargers have a socket on the unit and require you to bring your own cable. More flexible if you have or might have vehicles with different connector requirements, or if you want to use the charger for visitors with different vehicles.

For most UK homeowners with a single Type 2 EV, a tethered unit is more convenient. For households with multiple vehicle types or anyone who wants maximum flexibility, untethered is worth considering.

Smart Features: Why They Matter More Than Speed

On a 7kW unit, the smart features are often more valuable than the power output particularly for managing electricity cost.

Time-of-use tariff integration: Smart chargers can automatically schedule charging during overnight off-peak periods on tariffs like Octopus Intelligent or Economy 7, this can reduce the per-kWh cost of charging significantly. At off-peak rates, home charging a typical EV costs approximately 2–3p per mile versus 15–20p per mile on public rapid chargers.

Solar divert: If you have solar panels, a solar-compatible smart charger can divert surplus generation directly to the vehicle rather than exporting it to the grid. This maximises the value of solar generation and reduces grid electricity drawn for charging.

Load balancing: Smart chargers with load management capability monitor the household’s total electrical demand and adjust the charging rate to stay within safe limits useful both for single installations where peak domestic demand is high and for dual-charger installations.

Remote control and monitoring: App control, charging history, and energy consumption tracking are standard on most 7kW smart units. These features are also required for compliance with the Smart Charge Points Regulations 2021 all new chargers installed in the UK must be smart-capable.

The Grant Eligibility Dimension

For eligible homeowners, the OZEV EV Chargepoint Grant covers up to 75% of the installation cost, capped at £500 per socket. This grant is available to renters, flat owners, and some other residential categories; it is not available to homeowners in houses with off-street parking under the current scheme structure. The grant must be claimed through an OZEV-approved installer before installation begins.

If you are eligible, the £500 grant changes the cost comparison meaningfully. A 7kW smart charger installed at £900–£1,000 all-in becomes £400–£500 after the grant. A 3kW plug-based unit is not eligible. A 22kW installation costing £3,000–£5,000 is only partially offset.

For the full picture of what grants are available for your situation, see our dedicated EV charger grants guide.

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Which Should You Install? A Simple Decision Guide

Work through these questions in order:

1. Does your home have a three-phase electrical supply? If not, a 7kW unit is your realistic maximum. 22kW is not viable without a supply upgrade costing £3,000–£15,000+. If yes 22kW becomes available if your vehicle supports it.

2. What is your vehicle’s onboard charger (OBC) rate? Check the handbook or manufacturer’s website. If 3.6kW a 7kW charger will charge at 3.6kW (still faster than a 3kW unit but not the full 7kW). If 7kW or above a 7kW charger delivers its full output. If 11–22kW a 22kW charger is worth considering if supply is available.

3. What is your daily mileage? Under 30 miles daily a 3kW charger is technically sufficient, but a 7kW is still the better investment for the same grant-eligible cost. 30–200 miles daily 7kW overnight charging is fully adequate. Over 200 miles daily with multiple charging cycles 22kW if supply and vehicle compatibility allow.

4. Do you have solar panels or a time-of-use tariff? If yes smart features on a 7kW unit provide the most accessible and cost-effective integration.

5. Do you need to charge two vehicles? Two 7kW chargers with a dynamic load management system is the standard solution. A site survey establishes what your consumer unit can support. See our home EV charger installation page for more on multi-vehicle installations.

The answer for most people: a smart 7kW unit, installed by an OZEV-approved specialist, with a site survey to confirm your consumer unit can support a 32A dedicated circuit.

Frequently Asked Questions

Frequently Asked Questions

Which home EV charger is best for most UK homeowners?

A 7kW charger is the most practical choice for most UK homes, providing full overnight charging without requiring electrical upgrades. It is OZEV grant-eligible, compatible with all current EVs and PHEVs, supports smart tariff scheduling and solar integration, and works on the single-phase supply that nearly all UK homes have. For most drivers, it fully restores daily range overnight and costs far less to install than a 22kW unit.

Is a 7kW home charger sufficient for daily use?

Yes for the vast majority of drivers. A 7kW charger adds 25–30 miles of range per hour and fully charges a typical 60kWh battery in 8–10 hours. Since most drivers charge overnight and do not deplete the battery completely each day, real-world charging typically takes 4–6 hours, well within a standard overnight window.

Can I install a 22kW EV charger at home?

Technically yes, but most UK homes do not have three-phase power and upgrading may not be worth it. 97% of UK homes have single-phase power. Upgrading to three-phase costs £3,000–£15,000 depending on your DNO and distance, and is not always available. Your EV must also support 22kW AC charging; many popular models are capped at 7.4kW or 11kW regardless of charger output.

Can I have two 7kW chargers at home?

Yes, but two 7kW units running simultaneously draw 64A, which exceeds the available capacity of many domestic consumer units. The practical solution is dynamic load management, which distributes available capacity between chargers intelligently and avoids the need for an expensive supply upgrade. A site survey confirms what your specific consumer unit can support.

Is a 3kW home EV charger enough?

For PHEV drivers or those covering under 30 miles daily who top up every night, yes. For full EVs, 3kW chargers are increasingly outdated, taking 18–20 hours to fully charge modern EVs with larger batteries. For most full EV drivers, 7kW is the minimum worth installing.

What is the difference between 7kW and 7.4kW?

Nothing practically significant. 7.4kW is the technically accurate figure for a 32A single-phase circuit (32A × 230V = 7,360W). The terms are used interchangeably in everyday usage. Both refer to the same standard single-phase home charger specification.

Does a faster charger increase electricity cost?

No. The electricity cost per kWh is the same regardless of how fast the charger draws it. A 22kW charger does not cost more per unit of electricity than a 7kW charger; it simply uses that electricity faster. The total cost to charge a battery from a given state is the same regardless of charger speed.

What qualifications does my installer need?

Your installer should be OZEV-approved (required to process government grants), registered with NICEIC or NAPIT under the Competent Person Scheme (required for Part P self-certification), and hold a Level 3 EV charging qualification. See our guide to finding a certified EV charger installer for the full credentials checklist and questions to ask before booking.

Ready to Install the Right Charger for Your Home?

EV Install Pro is OZEV-approved and NICEIC-registered, carrying out home EV charger installations across London, Surrey, Kent, Essex, Hertfordshire, Berkshire, Buckinghamshire, East and West Sussex, West Yorkshire, South Yorkshire, and North Yorkshire.

Every installation starts with a site survey. We assess your consumer unit capacity, cable run options, and DNO requirements before quoting, so the price we give you is the price you pay. We handle OZEV grant applications, DNO notification, and full certification as part of the standard installation process.

For a full breakdown of what installation costs and what affects the price, see our EV charger installation cost guide. For information on grants you may be eligible for, see our EV charger grants guide.

Contact us to arrange a no-obligation site survey and written quote.