
7kW vs 22kW Home EV Charger UK: Which Power Level Do You Actually Need?
Choosing between a 7kW and 22kW home EV charger feels like a straightforward power question. But the answer hinges on three things you probably don't think about: your electrical supply, your car's on-board charger capacity, and how you actually drive. Get these wrong and you'll either overspend on infrastructure you don't need, or under-deliver on charging speed.
What These Numbers Actually Mean
The 7kW and 22kW ratings describe how much power the wallbox can deliver. That power comes from your home's electrical supply via either a single-phase or three-phase connection.
In the UK, most homes have single-phase supply—a single 230V line carrying up to about 100A. A 7kW charger uses roughly 32A of this capacity, which sits comfortably within domestic limits without expensive electrical upgrades.
Three-phase supply, available in some urban and rural areas, splits power across three 230V lines. This is what makes 22kW possible. A 22kW charger draws around 32A per phase, and your home can handle this if three-phase is already installed. If it isn't, adding three-phase typically costs £1,000–£3,000 or more, depending on your distance from the main supply.
Check your electricity bill or contact your supplier to confirm which you have. This decision branches right here: single-phase usually means 7kW is your practical limit; three-phase opens the 22kW option.
Your Car's On-Board Charger is the Bottleneck
Here's the crucial bit most people miss: your charger can only go as fast as your car allows. Every EV has an on-board charger (the component inside the car that converts AC to DC) with its own power limit.
Most newer EVs accept 7kW or 11kW on single-phase, and 11kW or 22kW on three-phase. Older models and smaller vehicles (think Nissan Leaf, early Renault Zoe) max out at 7kW. A few premium cars still don't support full 22kW on three-phase.
Before buying any charger, check your car's documentation or the manufacturer's website for its AC charging limit. Installing a 22kW wallbox into a car that only accepts 11kW is wasted expense—the car ignores the extra power.
Single-Phase Homes: 7kW Makes Sense
If you have single-phase supply, a 7kW charger is usually your sweet spot. Installation is straightforward, often requiring only a dedicated circuit and minimal rewiring. Costs typically run £400–£800 in labour and materials, before any grant funding.
Pros of 7kW on single-phase:
- No three-phase installation needed
- Fits standard domestic electrics
- Modest upfront cost
- Sufficient for most overnight charging
Cons:
- Slower than 22kW (takes roughly 7–9 hours to fully charge a 60kWh battery)
- Not ideal if you need rapid top-ups or have multiple vehicles
A 7kW charger adds about 30–35 miles of range per hour. For someone with a predictable routine—commuting 30 miles daily, charging overnight—this is perfectly adequate. You wake up to a full battery every morning.
Three-Phase Homes: 22kW for Faster Charging
If three-phase is already installed (check your supplier), 22kW becomes viable. Some properties already have it, particularly in business districts or newer housing developments. If you don't have it but are considering major electrical work anyway, adding three-phase might slot in cost-effectively.
Pros of 22kW on three-phase:
- Charges roughly three times faster than 7kW
- A 60kWh battery reaches ~80% in 2–3 hours
- Useful for unpredictable charging needs or multiple vehicles
- Future-proofs your setup as EV ranges increase
Cons:
- Three-phase installation adds significant upfront cost
- Wallbox itself is slightly more expensive
- Overkill if your car can only accept 7kW or 11kW
- No grid support charge from some suppliers if you're not already three-phase
The speed advantage is real, but weigh it against installation costs. If you pay £2,000+ to get three-phase installed, you need to genuinely need that charging speed to justify it.
How You Actually Use Your Car Matters Most
Your daily routine is the real deciding factor.
Go for 7kW if:
- You charge at home overnight and rarely need mid-day top-ups
- Your commute is under 80 miles round trip
- You have a predictable routine
- Three-phase isn't currently available
Consider 22kW (with three-phase) if:
- You have irregular charging patterns and need flexibility
- You own multiple EVs
- Your commute is longer or varies significantly
- You want to minimise charging time on a busy week
- Three-phase is already installed or easy to add
Most owners find 7kW more than adequate for daily life. Overnight charging is the cheapest power anyway, and few people need 80% charge in under an hour. The 22kW appeal is comfort and flexibility, not necessity.
Real Charging Times
A 60kWh battery (typical mid-range EV):
- From 10% to 80% on 7kW: roughly 5–6 hours
- From 10% to 80% on 22kW: roughly 1.5–2 hours
A 40kWh battery (smaller EV):
- 7kW: 3–4 hours
- 22kW: 1–1.5 hours
These assume no charger losses and your car supports the full power rating. Real-world times vary based on outside temperature, battery management strategy, and exact battery capacity.
The Bottom Line
Choose 7kW if you have single-phase supply or uncertain about your car's charging acceptance. It covers the majority of UK ownership patterns and avoids expensive upgrades. Choose 22kW only if three-phase is already there and your car supports it, or if you genuinely need faster charging often enough to justify the installation cost.
Start by confirming your electrical supply and car specs. Everything else follows from those two facts.
More options
- Ohme Home Pro EV Charger (Amazon UK)
- Zappi V2 EV Charger (myenergi) (Amazon UK)
- Wallbox Pulsar Plus EV Charger (Amazon UK)
- Andersen A2 EV Charger (Amazon UK)
- Portable Mode 2 EVSE Granny Cable (Amazon UK)