Home and business charging needs differ dramatically. A domestic user charging one vehicle overnight faces different technical requirements than a workplace managing fleet vehicles or offering employee charging. Most UK homes have a single-phase power supply suitable for 7kW charging, while commercial properties often feature three-phase supplies enabling faster 11-22kW charging.
Power output determines charging speed, but supply type limits what’s possible. Single-phase charging delivers a maximum 7.4kW through one conductor; three-phase charging delivers 11-22kW through three conductors. Your property’s electrical infrastructure dictates which configuration works without expensive upgrades.
Vehicle compatibility matters as much as supply capacity. Examples of single-phase vehicles include Opel Corsa-e and Mazda MX-30, while three-phase vehicles include Audi e-tron, Renault Zoe, Tesla Model X, and BMW i3. A three-phase charger won’t speed up charging if your vehicle only accepts single-phase input.
This guide explains power output differences, smart charging requirements for business versus home use, parking bay considerations, and how to choose the right charger configuration for your environment. Understanding these factors prevents purchasing equipment that can’t deliver the performance you need.
Power output and phase differences
Single-phase electricity is standard in UK homes with smaller power capacity, delivering electricity more slowly, making it ideal for typical household needs. Your home probably runs on single-phase unless you have unusually high power demands or industrial equipment.
Single-phase characteristics:
- Operates at 120-240 volts, delivering power up to 7.7kW
- Single-phase charger works on 230 volts at 32 amps current with maximum 7.4kW speed
- Takes approximately 8 hours to charge a 24kWh battery with a 3.68kW charger
- One live wire (phase), one neutral wire, one earth wire
- Suitable for overnight charging patterns
Check your electricity meter: if it shows 220/230V, you have single-phase; if you see 3×220/230V, 380/400V, or 380V, you can use three-phase. The meter label tells you immediately what supply type feeds your property.
Three-phase characteristics:
- Operates at around 400 volts or higher, delivering power up to 43kW or more
- Works on 400 volts at 16 amps current with highest charging speed 11kW
- Reduces charging time to around 2 hours for the same 24kWh battery with 11kW charger
- Three live wires, one neutral wire, one earth wire
- Typically found in commercial or industrial buildings, though larger homes may also require three-phase power
Power delivery splits across phases in three-phase systems. An 11kW three-phase charger draws roughly 16 amps per phase instead of 48 amps from single phase. This balanced distribution prevents overloading any single conductor.
Vehicle onboard charger limits:
Your vehicle’s onboard charger determines actual charging speed regardless of supply type. The Vauxhall Corsa-e only has a maximum charging rate of 7.4kW, so it can only charge at this rate even with 3-phase power, meaning full charge takes up to 8 hours.
If you have a single-phase wallbox and a three-phase electric car, or a three-phase wallbox and a single-phase electric car, your car will charge with one phase in both cases, and the weakest link in the charging chain will define the maximum speed. The system automatically drops to the lowest common capability.
Upgrading supply type:
Upgrading to a three-phase supply is very expensive, often costing thousands of pounds, and can be a very time-consuming process. Contact your local Distribution Network Operator (DNO) for exact costs. They assess your area’s capacity and quote for the necessary infrastructure work.
Three-phase upgrades require:
- New service cable from the street to property
- Upgraded meter and consumer unit
- Modified internal wiring for balanced load distribution
- DNO approval and connection fees
- Potential transformer upgrades if the area capacity insufficient
Most people are fine with single-phase power and can charge their car with a 7kW EV charger in up to 8 hours. Overnight charging suits most driving patterns without needing expensive supply upgrades.
Commercial three-phase benefits:
Three-phase chargers suitable for both commercial settings and homes with high power needs, ideal for businesses with fleet vehicles or commercial charging stations. Multiple vehicles charging simultaneously benefit from higher total capacity.
Larger 3-phase Mode 3 charging points usually found in commercial and public settings can have ratings of 11kW, 22kW or 43kW. These installations need professional electrical design to balance loads and prevent supply overload.
Three-phase enables multiple chargers from the same supply. A 60kW three-phase connection can power three 22kW chargers or six 11kW units. Single-phase supplies struggle to support more than one 7kW charger without upgrades.
Cost comparison:
Single-phase smart chargers are sometimes slightly cheaper than three-phase chargers, with a nominal difference of around EUR 40-50. Equipment cost differences pale compared to supply upgrade expenses.
Installation complexity affects pricing more than equipment type. Three-phase installations need:
- Larger cable gauges for higher currents
- Three-pole protection devices instead of single-pole
- Load balancing across phases
- More complex testing and certification
Based on electricity pricing, battery size, and charger power, it costs around £8 to charge 24kWh battery with 3.68kW charger; with 11kW three-phase charger, it costs around £2 for the same battery. These figures assume off-peak tariff rates and a full battery charge from empty.
Learn more in our guide: Electrical load management for EV charging systems
Smart charging control for business vs home use
Since June 30, 2022, The Electric Vehicles (Smart Charge Points) Regulations 2021 demand all new home chargers are smart. This applies equally to domestic and commercial installations, but business requirements extend further.
Home smart charging features:
- Schedule charging during off-peak times for cheaper electricity rates
- Monitor and report energy use via app
- Balance charging if multiple devices are using power at the same time
- Integrate with solar panels and home batteries
- User override options for urgent charging needs
- Single-user authentication and billing
Peak times generally Monday-Friday 10am-2pm and 6pm-10pm; charging during off-peak hours costs less per kW than peak hours. Smart chargers automatically shift charging to these cheaper periods without manual intervention.
Domestic systems prioritise simplicity. One user controls one charger, charging one vehicle. Authentication happens through a smartphone app or RFID card. Energy monitoring shows household consumption patterns helping optimise usage.
Commercial smart charging requirements:
Business installations need additional functionality:
- Multi-user access control and authentication
- Usage tracking per employee or department
- Billing and reimbursement reporting
- Fleet management integration
- Prioritisation rules for business-critical vehicles
- Visitor access with guest charging capabilities
Workplace Charging Scheme chargepoints must be used by staff or fleet only, except for charities and small accommodation businesses where guests and visitors may use chargepoints. Access control prevents unauthorised use and tracks who charges when.
Dynamic load management for business:
When your company has several EV chargers, dynamic load balancing prevents any load on grid or electrical system by making sure each charger receives precisely the right amount of electricity at the right time. Commercial sites with limited supply capacity need this to avoid expensive upgrades.
If two electric cars are charging and sharing 30 amps, they each get 15 amps, but if there’s only one car it would get full 30 amps. The system continuously adjusts power distribution based on how many vehicles are connected and their charging states.
Multiple chargers require sophisticated management:
- System tracks each vehicle’s state of charge, remaining charging time and total energy consumption to allocate power intelligently
- Vehicle approaching full charge receives less power, whilst others with lower battery levels get increased allocation
- Queue management for when demand exceeds available capacity
- Automatic failover if individual chargers develop faults
Business billing and reimbursement:
Employees charging company vehicles at home need accurate usage tracking. Zaptec’s built-in EV driver reimbursement makes it easy to track usage, allocate costs, and simplify claims through an intuitive app. This eliminates disputes about electricity costs and streamlines expense processing.
Commercial charging stations require payment integration:
- Credit card readers for public access
- RFID card authentication for employee use
- Mobile app payment options
- Backend integration with accounting systems
- VAT-compliant invoicing
Some businesses offer free charging as an employee benefit. Smart systems still track usage for tax reporting and capacity planning even when no payment changes hands.
Network connectivity requirements:
Connected EV charging stations establish a wireless connection, typically via Bluetooth or internet, enabling real-time communication between charging station, car, EV driver, and the electrical circuit. Commercial installations need more reliable connectivity than domestic setups.
Business networks require:
- Redundant internet connections for continuous operation
- Cellular backup if the primary connection fails
- VPN security for sensitive charging data
- Integration with building management systems
- Remote monitoring and diagnostics
Test Wi-Fi signal strength at installation site to keep smart features working. Commercial car parks often need multiple access points or cellular connectivity due to concrete construction blocking signals.
Demand response participation:
Charge points must respond to grid frequency variations within 2 seconds and participate in automated demand reduction schemes during grid stress events. Commercial installations can generate revenue by providing flexibility services to grid operators.
Businesses with multiple chargers become virtual power plants. During peak demand periods, charging reduces automatically across the fleet. Grid operators pay for this flexibility, offsetting installation costs over time.
Parking bay and access considerations
Physical layout affects charger placement more than technical specifications. Car park design, bay dimensions, and vehicle access patterns determine where chargers can install and how many units fit.
Domestic parking requirements:
Your charger needs to live where your EV sleeps, not on street where cables could turn pavements into an obstacle course. Dedicated off-street parking is mandatory for grant-funded installations and strongly recommended for all home charging.
Single driveways need:
- Minimum 2.4m width for vehicle access
- 5m depth for parking plus walking space
- Wall-mounted charger on the house or garage wall
- Cable management preventing trip hazards
- Clear access for emergency services
Check which side of the charging port is located on your EV model before installation to plan accordingly. Mounting the charger on the wrong side means the cable stretches across the vehicle or doesn’t reach at all.
Shared driveways complicate installations. Both properties need access without cables crossing neighbours’ parking spaces. Legal right-of-way documentation proves you can install equipment without neighbour consent, though good relationships help avoid disputes.
Garage installations:
Internal garage mounting protects chargers from the weather but creates ventilation concerns. Chargers handle high currents for long periods, requiring adequate ventilation to prevent overheating. Unheated garages face condensation and temperature extremes.
Garage door clearance matters. Roller doors and up-and-over doors need chargers positioned where they won’t interfere with door operation. Side-hinged doors require space for door swing plus cable management.
Commercial parking bay design:
New non-residential properties with over 10 parking spaces must have a minimum of one charge point, plus a cable route for every five parking spaces after that. Building Regulations Part S sets these minimums; good design exceeds them.
Bay dimensions for EV charging:
- Standard bay 2.4m x 4.8m minimum
- Accessible bays 3.6m x 4.8m for wheelchair access
- Socket outlet height 0.75-1.2m from finished floor level, with displays 1.2-1.4m for accessibility
- Clear walkway 1.2m wide around charger
- Turning circle radius for vehicles up to 5m long
Guidance on location and accessibility of charging points updated to account for PAS 1899:2022 Electric vehicles – Accessible EV charging points specification. This ensures wheelchair users can operate chargers independently.
Parking allocation strategies:
Commercial sites face allocation decisions:
- First-come-first-served open bays
- Assigned bays for specific employees or fleet vehicles
- Reserved bays for visitors or customers
- Mixed allocation balancing different user needs
Assigned bays prevent charging disputes but reduce flexibility. If the assigned user doesn’t need charging, the bay sits empty while other vehicles wait. Open allocation maximises utilisation but creates competition during busy periods.
Cable management:
Tethered cables typically 5m or 7.5m length; untethered allows longer cables if needed. Cable length affects which bays can charge from a single charger location.
Post-mounted chargers between two bays serve both spaces from one unit. This halves equipment costs but requires careful cable routing to prevent:
- Cables crossing adjacent bays
- Trip hazards in walkways
- Vehicle damage from driven-over cables
- Theft of expensive untethered cables
Overhead cable reels work in some commercial settings. These drop cables from ceiling height to the vehicle, eliminating ground-level trip hazards. High capital costs limit their use to premium installations.
Future capacity planning:
Major renovations to commercial buildings with more than 10 parking spaces must provide cable routes for future chargers, even if not installing them immediately. Ducting and cable routes installed during construction cost far less than retrofitting later.
Plan for 30-50% of parking bays eventually needing chargers. This percentage increases annually as EV adoption grows. Installing conduits now prevents disruptive trenching work when demand rises.
Three-phase chargers offer future-proofing as vehicles with larger battery capacities become more prevalent. Infrastructure supporting 22kW chargers today accommodates next-generation vehicles without rewiring.
Access control and signage:
Commercial bays need clear marking:
- Road surface markings showing EV-only zones
- Vertical signage visible from distance
- Usage instructions at each charger
- Emergency contact information
- Payment or authentication instructions
Enforcement prevents ICE vehicles (Internal Combustion Engine) from blocking charging bays. Some businesses use automatic bollards or height barriers. Others rely on parking management patrols and penalty charges.
Choosing the right charger for your environment
Match charger specifications to usage patterns, vehicle types, and electrical infrastructure. Overspecifying wastes money on capabilities you’ll never use; underspecifying creates frustration and expensive retrofits.
Domestic selection criteria:
Three-phase power charges EV faster, but it’s rare in UK homes and costly to upgrade if you don’t already have it. Check your supply type before considering three-phase chargers.
Home charging suits:
- Daily commutes under 40 miles
- Overnight parking 6-8 hours minimum
- Single-vehicle households
- Predictable charging schedules
- Off-peak tariff optimisation
Most people are fine with single-phase power and can charge their car with a 7kW EV charger in up to 8 hours. Calculate your daily mileage and typical battery depletion. If you drive 30 miles daily, you use roughly 9.5kWh. A 7kW charger replaces this in 90 minutes.
When to consider three-phase at home:
- Multiple EVs charging simultaneously
- Large battery vehicles (100kWh+) needing faster turnaround
- High daily mileage exceeding single overnight charge capacity
- Property already has a three-phase supply for other equipment
- Future-proofing for additional EVs
Choosing a three-phase charger offers future-proofing by accommodating larger battery EVs and faster charging needs. But pay premium prices only if your supply supports it and usage patterns justify faster charging.
Commercial selection criteria:
Business installations need detailed load analysis:
- Number of vehicles charging simultaneously
- Dwell time (how long vehicles typically park)
- Charging urgency (fleet scheduling vs employee convenience)
- Existing electrical supply capacity
- Budget for supply upgrades vs. load management
Dynamic load balancing helps prevent load on grid without expensive building work, allowing you to charge more EVs without upgrading the existing power supply. This becomes essential when supporting 5+ chargers from a limited supply capacity.
Fleet charging differs from employee charging. Fleet vehicles often need guaranteed availability and faster charging between shifts. Employee charging accommodates longer dwell times with lower power acceptable.
Charger type comparison:
7kW single-phase home charger:
- Suitable for most domestic users
- Overnight charging is adequate for daily commuting
- Lower equipment and installation costs
- Compatible with all UK single-phase supplies
- Typical installation costs £800-1,200, including labour
22kW three-phase charger:
- Can charge an electric vehicle in as little as 30 minutes at commercial stations
- Requires a three-phase supply and a compatible vehicle
- Higher equipment costs £1,500-2,500
- Installation requires larger cables and protection devices
- Mainly commercial and industrial applications
11kW three-phase charger:
- Middle ground between domestic and heavy commercial
- Some modern homes with a three-phase supply can use
- Charges twice as fast as 7kW units
- Growing vehicle compatibility as the EV market matures
- Installation costs £1,200-1,800 typically
Tethered vs untethered:
Tethered chargers cost more than untethered due to included cable. Consider usage patterns when deciding.
Choose tethered when:
- Single-vehicle household with consistent usage
- Convenience prioritised over flexibility
- Security concerns about cable theft
- Users prefer grab-and-go charging
- All household vehicles use the same connector type
Choose untethered when:
- Multiple vehicles with different connector types
- Cable flexibility is important for varying parking positions
- Lower initial cost preferred
- Willing to manage a separate charging cable
- Future vehicle changes likely
Both tethered and untethered chargers can offer smart features like app control, scheduled charging, and energy monitoring. Smart functionality doesn’t depend on cable type.
Smart features priority:
Essential features for all installations:
- Smart chargers schedule off-peak charging, adjust to grid needs, and let you track costs via app
- Remote access for monitoring and control
- Usage reporting and energy analytics
- Load balancing capability
- Firmware update capability
Business-specific features:
- Multi-user authentication and access control
- Detailed billing and reporting
- Integration with fleet management systems
- Payment processing for guest charging
- Network management for multiple locations
Solar integration attracts growing interest. Smart chargers integrate with solar panels and home batteries to maximise renewable energy use and minimise grid electricity costs. This feature justifies premium pricing for environmentally-conscious users.
Total cost of ownership:
Look beyond purchase price:
- Installation complexity and labour costs
- Electrical upgrade requirements
- Ongoing electricity costs based on tariff
- Maintenance and warranty coverage
- Potential grant funding reducing upfront costs
Smart scheduling enables access to time-of-use tariffs, reducing charging costs by 40-60%. A charger costing £200 more but saving £300 annually on electricity pays for itself in 8 months.
Commercial installations must calculate return on investment:
- Employee satisfaction and retention benefits.
- Fleet operational efficiency improvements.
- Environmental sustainability credentials.
- Future-proofing against regulatory changes.
- Revenue from guest charging or grid services.
Professional assessment recommended:
Don’t self-diagnose complex installations. Professional installers assess a home’s wiring capacity and determine if it can handle an extra load. They identify limitations you might miss and design solutions meeting your actual needs rather than perceived requirements.
Diligent Electrical Contractors provides free EV charger installation site surveys assessing your property’s electrical capacity, parking layout, and usage requirements. We recommend appropriate charger specifications matching your supply type and charging patterns without overselling unnecessary features.