- 7kW is the right choice for 99% of UK homes - single-phase supply is standard, and overnight charging adds 30 miles/hour, fully charging a 60kWh battery in 8-12 hours
- 22kW requires three-phase power - only around 1% of UK homes have this, and upgrading costs £3,000-£5,000 from your DNO
- Most EVs cap at 7kW anyway - the onboard charger in cars like the Nissan Leaf, VW ID.3, and MG4 cannot accept more than 7kW regardless of charger speed
- Total cost difference is significant - a 7kW charger costs £800-£1,500 installed vs £4,000-£7,000 for 22kW with a three-phase upgrade
- 22kW only makes sense commercially - workplaces, fleet depots, and the rare homes already wired for three-phase benefit from 90 miles of range per hour
If you are researching home EV chargers, you have probably seen 7kW and 22kW options and wondered whether faster charging is worth the extra cost. The short answer for most UK homeowners: it is not. A 7kW charger on your existing single-phase supply will fully charge any electric car overnight.
This guide breaks down exactly when 22kW makes sense, what it costs to upgrade to three-phase power, and why 7kW is the smarter choice for the vast majority of UK households.
7kW vs 22kW: Head-to-Head Comparison
A 7kW charger operates on single-phase power at 32 amps, which every UK home already has. A 22kW charger needs a three-phase supply at 32 amps, which requires a costly upgrade from your Distribution Network Operator (DNO). Here is how they compare across the metrics that matter most.
| Specification | 7kW (Single-Phase) | 22kW (Three-Phase) |
|---|---|---|
| Power Supply Required | Single-phase (standard UK) | Three-phase (1% of UK homes) |
| Charging Speed | ~30 miles range per hour | ~90 miles range per hour |
| Time to Charge 60kWh Battery | 8-12 hours (overnight) | 3-4 hours |
| Charger Unit Cost | £800-£1,500 installed | £1,000-£2,000 installed |
| Three-Phase Upgrade Cost | Not required | £3,000-£5,000 from DNO |
| Total Installed Cost | £800-£1,500 | £4,000-£7,000 |
| Compatible With Most EVs | Yes (matches onboard charger) | Limited (most EVs cap at 7kW) |
| Best For | Home charging (overnight) | Commercial, workplace, fleet |
Why 7kW Is All Most UK Homeowners Need
The average UK driver covers 20-30 miles per day. A 7kW charger replaces that range in under an hour, and a full overnight charge (plugging in at 10pm, unplugging at 7am) delivers over 250 miles of range. For the typical household, faster charging simply does not add practical value.
There is also a critical technical limitation that many buyers overlook. The speed at which your EV charges is determined by its onboard charger, not the wallbox. Most electric cars sold in the UK, including the Nissan Leaf, Volkswagen ID.3, MG4, and Hyundai Ioniq 5, have a 7kW onboard charger. Plugging these cars into a 22kW wallbox will not charge them any faster. They will still draw a maximum of 7kW.
Only a handful of EVs can actually use 22kW AC charging. The Renault Zoe (22kW onboard charger), Tesla Model S and Model X (up to 16.5kW), and select Mercedes-Benz models (11kW) are among the few that benefit. Check your vehicle’s AC charging specification before investing in a faster charger.
The financial case is equally clear. A 7kW home charger costs £800-£1,500 fully installed. A 22kW charger costs £1,000-£2,000 for the unit alone, plus £3,000-£5,000 for the DNO to install a three-phase supply. That is a total outlay of £4,000-£7,000 for charging speed that your car probably cannot use.
When 22kW Three-Phase Charging Makes Sense
There are three legitimate scenarios where 22kW charging is worth the investment. All of them involve either existing three-phase infrastructure or commercial requirements where charging speed directly affects revenue or operations.
Your home already has three-phase power. Some larger UK properties, rural homes, and conversions of commercial buildings already have three-phase supplies. If you have this infrastructure, the upgrade cost disappears and a 22kW charger becomes a sensible choice, provided your EV can accept more than 7kW AC.
Workplace and commercial charging. Businesses need vehicles charged and ready quickly. A workplace charger running at 22kW can fully charge a fleet vehicle during a lunch break, whereas a 7kW charger needs a full shift. Most commercial premises already have three-phase supplies, making this the most common use case for 22kW chargers.
High-mileage drivers with compatible EVs. If you drive 100+ miles daily and own a Renault Zoe or another EV with a 22kW onboard charger, the faster top-up times can make a material difference to your routine. You could recover 90 miles of range in a single hour. This applies to a very small percentage of UK EV owners.
Do You Have Three-Phase Power?
Most UK homeowners do not have three-phase power and may not realise what upgrading involves. Your electricity meter and consumer unit will tell you which supply type you have. Single-phase has one main fuse (typically 60A or 100A), while three-phase has three.
If you do not have three-phase, getting it installed means contacting your DNO (the company that manages the electricity network in your area, not your energy supplier). The process typically takes 8-12 weeks and costs £3,000-£5,000 depending on the distance from the nearest three-phase cable to your property.
You will also need your consumer unit upgraded to a three-phase board, which adds £500-£1,000 to the bill. Your DNO will survey your property before quoting, and the final cost depends on whether new cabling needs to be laid from the street. In some rural areas, costs can exceed £5,000.
Some installers advertise 22kW chargers without mentioning that you need three-phase power. Always confirm your supply type before purchasing. If an installer does not ask about your electrical supply as the first question, find a different installer.
Chargers That Offer Both Options
A small number of EV chargers are available in both 7kW and 22kW variants, giving you flexibility if you plan to upgrade your supply in future. The Myenergi Zappi is the most popular example. The same physical unit supports both single-phase (7.4kW) and three-phase (22kW) installations. You buy the appropriate version for your current supply.
Several commercial-grade chargers also offer 22kW, including models from Easee, ABB, and Schneider. These are primarily designed for workplace and public charging, where three-phase supplies are standard. For home use, the Zappi remains the standout choice for three-phase households because it also offers solar divert functionality, allowing you to charge your EV using surplus solar energy and reduce your running costs further.
Our Recommendation
For the vast majority of UK homeowners, a 7kW single-phase charger is the clear choice. It costs £800-£1,500, works with your existing electrical supply, matches the onboard charger speed of most EVs, and delivers a full charge overnight. Spending £4,000-£7,000 on a 22kW setup when your car can only draw 7kW is wasted money.
If you already have three-phase power and an EV with a higher onboard charger capacity, 22kW is a worthwhile upgrade. For businesses running EV fleets, three-phase charging is effectively essential for keeping vehicles on the road.
Everyone else should put the £3,000-£5,000 they would spend on a three-phase upgrade towards a better charger, a longer cable run, or simply more electricity to charge with. Compare quotes from OZEV-approved installers to find the best deal on a 7kW home charger for your property.
