If you are comparing EV chargers for your home, the difference between 7kW and 22kW can appear significant. A 22kW charger sounds more future-proof and considerably faster, but for most homes in Redhill and across Surrey, a 7kW charger is usually the more practical choice.
The right option depends on three key factors:
- The electricity supply to your property
- Your vehicle’s maximum AC charging rate
- How much driving you do and how quickly you need to recharge
This guide explains how 7kW and 22kW chargers work, what installation involves, and the likely costs for a Surrey homeowner.
What does 7kW or 22kW mean?
The kilowatt rating describes the maximum power a charger can deliver to your vehicle. In simple terms, a higher rating can add more driving range in less time, but only if your home and car can both support it.
| Charger | Typical supply | Approximate range added per hour |
|---|---|---|
| 7kW | Single-phase | Around 25–30 miles |
| 22kW | Three-phase | Around 70–90 miles |
The exact range depends on the vehicle’s battery size, efficiency, weather, temperature and charging losses.
A typical 7kW charger can add approximately 200 miles of range during an eight-hour overnight charge. For most daily commutes from Redhill, Reigate, Earlswood, Merstham or surrounding Surrey areas, that is more than sufficient.
A 22kW charger could potentially recharge a 60kWh battery in around three hours, compared with approximately eight to ten hours using a 7kW charger. However, that faster charging speed is not always achievable in practice.
7kW home chargers: the normal choice for Surrey properties
Most UK homes, including the majority of properties in Surrey, have a single-phase electricity supply. A standard 7kW charger operates at approximately 230V and draws around 32 amps on a dedicated circuit.
Benefits of a 7kW charger
- Compatible with the electrical supply found in most homes
- Usually suitable for overnight charging
- Lower installation and equipment costs
- Less likely to require a supply upgrade
- Compatible with the majority of electric cars
- Smart charging can schedule charging during cheaper tariff periods
- Suitable for most homeowners, landlords and single-EV households
Modern 7kW smart chargers can also include features such as scheduled charging, solar integration, load management and remote monitoring through a mobile app.
For many homeowners, the most efficient approach is to plug in when arriving home and allow the vehicle to charge overnight. You may never need to use the charger’s full capacity during a typical day.
22kW chargers: when do they make sense?
A 22kW AC charger normally requires a three-phase, 400V electricity supply. Three-phase power is common in commercial and industrial premises, but it is relatively rare in ordinary domestic properties.
A 22kW charger draws approximately 32 amps across each of the three phases. It is therefore not simply a more powerful version of a 7kW charger that can be connected to any home.
A 22kW installation may be worthwhile if:
- Your home already has a suitable three-phase supply
- Your vehicle can accept 22kW AC charging
- You regularly drive long distances
- You have several electric vehicles
- You need rapid turnaround between journeys
- The property has a business, fleet or small commercial use
For example, a household with two EVs, frequent long-distance travel or vehicles being used throughout the day may benefit from a higher-power system. Even then, the charger must be matched to the cars and the available electrical capacity.
Does a 22kW charger make every EV charge faster?
No. Your car’s onboard AC charger is often the limiting factor.
Many electric cars sold in the UK have a maximum AC charging rate of 7kW or 7.4kW. Some vehicles can accept 11kW AC through a three-phase supply, while fewer models support the full 22kW.
If your car has a 7kW onboard charger, connecting it to a 22kW wallbox will not make it charge at 22kW. It will still charge at approximately 7kW.
Similarly, an EV with an 11kW onboard charger will generally charge at up to 11kW, even when connected to a 22kW unit.
Before choosing a charger, check your vehicle handbook or manufacturer specification for the “maximum AC charging power”. This is often more important than the maximum output printed on the charger.
Single-phase versus three-phase: how can you tell what you have?
Most residential properties in Redhill have single-phase electricity. However, you should confirm this before planning a 22kW installation.
Possible signs of a three-phase supply include:
- Three-phase mentioned on your electricity paperwork
- A commercial-style electricity intake or meter arrangement
- Three separate phases shown on electrical documentation
- A property previously used for commercial, agricultural or industrial purposes
- An electrician confirming three-phase capacity during a site survey
A smart meter does not automatically mean you have three-phase power. Likewise, the appearance of a consumer unit alone is not always conclusive.
Do not remove covers or interfere with sealed equipment to investigate your supply. An NICEIC Approved Contractor can inspect the installation safely and confirm whether the incoming supply, consumer unit and cabling are suitable.
Consumer unit and cable requirements
Whichever charger you choose, it should be connected to a suitable dedicated circuit rather than sharing a general socket circuit.
An installer will typically assess:
- The condition and capacity of the consumer unit
- Whether there is a spare way for the EV circuit
- Main fuse and incoming supply capacity
- Earthing and bonding arrangements
- Cable route, length and voltage drop
- Required RCD and DC fault protection
- Whether load management is appropriate
- Whether underground or external cabling needs mechanical protection
Depending on the route and installation design, the cable may need to be larger than the minimum expected size. Long cable runs, outbuildings, detached garages, driveway crossings and buried routes can all affect the specification.
Your installer may also recommend dynamic load balancing. This monitors the property’s total electricity demand and temporarily reduces the charger’s output when high-load appliances, such as an electric shower, heat pump or induction hob, are operating.
That can help avoid overloading the supply and may prevent the need for an unnecessary upgrade.
DNO notification and approval
The Distribution Network Operator (DNO) manages the local electricity network. EV charger installations may need to be notified to the DNO, depending on the charger, connection arrangement and local requirements.
For a standard 7kW import-only home charger, the installer will usually manage the relevant connect-and-notify process after installation, provided the property’s supply is suitable. This is commonly referred to as a G98-style notification, although the exact process can vary.
A 22kW three-phase charger normally involves more detailed checks. It may require a prior application and approval before connection, particularly where a new three-phase supply or network reinforcement is needed. Bidirectional systems, such as vehicle-to-grid or vehicle-to-home chargers, can also have additional requirements because they export electricity to the network.
Your electrician should confirm the DNO process before work begins. A reputable installer will not simply connect a high-powered charger and leave the homeowner to deal with compliance afterwards.
Further technical information is available in the UK Government’s residential chargepoint minimum technical specification.
Typical EV charger installation costs in Surrey
Prices vary according to the charger brand, cable route, consumer unit, groundwork and DNO requirements. As a general 2026 guide:
- 7kW straightforward installation: approximately £850–£1,250
- 7kW installation with longer cable runs or electrical upgrades: approximately £1,250–£1,600 or more
- 22kW installation where three-phase is already available: approximately £1,200–£1,800
- Three-phase supply upgrade: often several thousand pounds in addition to the charger installation
A 22kW installation can therefore become considerably more expensive if your home currently has single-phase power. In many cases, the extra cost cannot be justified because the vehicle itself is limited to 7kW or 11kW AC charging.
The best way to establish an accurate price is with a site assessment. Cable length, parking position and consumer unit location can make a substantial difference to the final quotation.
Which charger should a Redhill homeowner choose?
For most homes in Redhill and Surrey, a 7kW smart charger is the sensible option. It provides reliable overnight charging, works with a standard single-phase supply and is compatible with most electric vehicles.
Consider 22kW only when all three of the following apply:
- Your property already has, or can economically obtain, three-phase power.
- Your vehicle can accept more than 7kW AC charging.
- You genuinely need faster charging between journeys.
If you are unsure, ADS Electrical can assess your supply, consumer unit, parking arrangement and vehicle requirements before recommending a suitable charger. We provide free quotes within 24 hours and carry out EV charger installations for homes and businesses across Redhill, Earlswood, Meadvale, Merstham, Salfords, Reigate and surrounding Surrey areas.
For professional advice, contact ADS Electrical for EV charging solutions Redhill. As a NICEIC Approved Contractor, we manage the installation correctly from the initial assessment through to testing and notification.
Frequently asked questions
Can a 22kW charger be installed at a single-phase home?
A genuine 22kW charging output requires three-phase power. Some chargers can be configured for single-phase use, but they will normally operate at around 7kW rather than 22kW.
Will a 7kW charger charge my EV overnight?
Usually, yes. An eight-hour overnight session can add around 200 miles of range, depending on the car and charging conditions.
Do I need to upgrade my consumer unit?
Not always. The existing consumer unit may be suitable if it has capacity and meets current safety requirements. If it is old, damaged or lacks suitable protection, an upgrade may be recommended.
Is three-phase power common in Redhill homes?
No. Most domestic properties have single-phase supplies. Three-phase is more common in commercial premises, industrial units and some specialist properties.
How do I know my car can use 22kW AC charging?
Check the vehicle manufacturer’s specifications for its maximum AC charging rate. If it is listed as 7kW or 11kW, a 22kW charger will not provide the full 22kW output.
Conclusion
For the typical Surrey home, 7kW remains the best balance of charging speed, compatibility, cost and installation simplicity. It can comfortably recharge most EVs overnight without requiring a three-phase supply or expensive network upgrade.
A 22kW charger can be valuable for high-mileage households, multiple EVs or properties that already have three-phase electricity: but it is not automatically faster for every vehicle.
Before choosing, have your electricity supply, car specifications and proposed cable route assessed by a qualified electrician. The right charger is not necessarily the most powerful one; it is the one that matches your home, vehicle and daily driving needs.