7.4 kW vs 22 kW: Which EV Charger Is Right for a Typical East Kilbride Home?

Upgrading to a home EV charger is one of the best quality-of-life improvements you can make as an EV owner. The first big decision you’ll face is power rating: 7.4 kW (single-phase) or 22 kW (three-phase). On paper, 22 kW looks three times faster—but for most East Kilbride homes, 7.4 kW is the smart, cost-effective choice. This guide explains why, covering single-phase vs three-phase supplies, tethered vs untethered cables, load management, and how smart tariffs affect real-world costs.

Service overview: EV Charger Installation in East Kilbride
Typical costs: Pricing

TL;DR (quick answer)

Most EK homes are single-phase, which supports up to 7.4 kW AC.
22 kW needs a 3-phase supply (uncommon in homes) and an EV that accepts >7 kW AC—many don’t.
A good 7.4 kW smart charger refills overnight, works with off-peak tariffs, and is simpler/cheaper to install.
22 kW can make sense if you already have 3-phase (or are building a new property), you have multiple EVs, and your cars accept high AC charge rates.
Unsure? Book a home survey and we’ll confirm your supply type, fuse rating, and the best setup for your driveway and usage.

First principles: how fast will each option charge?

Charging speed depends on three limits working together:

Your supply (single-phase vs three-phase)
The charger (7.4 kW or 22 kW)
Your car’s onboard AC charger (often 7–11 kW, sometimes 22 kW)

Typical real-world rates

3-pin “granny” lead (~2.3 kW): ~8–10 miles of range per hour (backup only).
7.4 kW AC (single-phase): ~25–30 miles of range per hour; perfect for overnight top-ups.
11–22 kW AC (3-phase): ~35–60+ miles per hour—only if your home and car both support it.
DC rapid (public): 50 kW+; not a home solution.

Key takeaway: even with a 22 kW wallbox, many EVs cap AC charging at 7–11 kW. If your car’s onboard charger is 7 kW, a 22 kW unit won’t speed it up at home.

Single-phase vs three-phase in East Kilbride homes

Single-phase (most homes): Supports 7.4 kW chargers. Straightforward installation, minimal disruption, typically the best value.
Three-phase (rare in domestic): Supports 11–22 kW chargers. You’ll know if you have it—three main incoming conductors, larger/service head, often newer high-demand properties or commercial premises.

Upgrading to 3-phase is possible but involves DNO (network operator) works, costs, and timescales. For most households, the practical benefits don’t outweigh the expense—especially with smart tariffs making overnight 7.4 kW charging extremely effective.

The overnight reality: why 7.4 kW is “fast enough”

Let’s say you arrive home with 30% remaining on a 60 kWh battery and want to reach 80% by morning.

Energy needed ≈ 30 kWh.
At 7.4 kW, that’s ~4–5 hours—well within a typical off-peak window.
With smart scheduling, you can target cheap hours only and still wake up full.

Unless you routinely arrive empty and need to dash out again within 1–2 hours, 7.4 kW covers real life—quietly, cheaply, and with less strain on your home supply.

When 22 kW might make sense

You already have 3-phase (new build or combined home/workspace).
Your EV(s) accept 11–22 kW AC and you regularly need rapid turnarounds at home (e.g., multiple long trips in a day).
You’re future-proofing a property with high electrical demand (EVs, heat pump, big workshop) and want dual chargers that can share load across phases.

If you’re setting up a new build or substantial refurb, we can explore 3-phase provision during design; otherwise, most households are better served by a strong 7.4 kW smart setup with good load management.

Tethered vs untethered: convenience or clean look?

Regardless of power rating, you’ll choose tethered (fixed cable) or untethered (Type 2 socket):

Tethered (our most popular):
- Pros: Fastest everyday use—walk up and plug in. No rummaging for cables in the rain.
- Cons: A visible cable; you’re “locked” to cable length/type (we’ll size it to suit your driveway).
Untethered:
- Pros: Clean façade, flexible for future cars; less tempting in shared/visible spots.
- Cons: Slightly more faff; cable lives in the boot/garage.

Tip: If you often park nose-in one day and tail-in the next, pick tethered with 7.5 m for reach. In communal bays, untethered keeps things tidy.

Load management: protect your main fuse (and avoid nuisance trips)

Scottish homes commonly have a 60–100 A main fuse. Big appliances (electric showers, induction hobs, heat pumps) plus EV charging can push the limits. Modern chargers offer dynamic load management:

The charger monitors total household load and automatically reduces charging current if you’re near the limit.
Once the tumble dryer/oven switches off, the charger ramps back up.
This protects the supply without you doing anything and can avoid expensive fuse upgrades.

For most single-phase homes, 7.4 kW + load management is the sweet spot—fast overnight, zero stress.

Smart tariffs & scheduling: where the big savings are

Power rating is only half the story—when you charge matters just as much:

Time-of-use tariffs (off-peak/overnight windows) can halve or more your cost per kWh.
Your charger/app can schedule to start at, say, 00:30 and stop at 04:30, targeting cheap energy only.
Some setups integrate with the car’s API or even solar PV, automatically pulling more/less based on generation or price.

A reliable 7.4 kW smart charger with good scheduling and reporting will save more money than chasing an extra few kW of AC power you’ll rarely use.

Cable runs, placement & connectivity

Whether 7.4 or 22 kW, good installation is about route and reliability:

Neat cable route from your consumer unit to the charger with minimal surface runs.
Placement that suits your parking orientation—ideally reach both front and rear charge ports.
Wi-Fi test at the charger position; if the signal is weak, consider 4G modules or a Wi-Fi extender so smart features work flawlessly.

During the survey we’ll photograph your consumer unit, meter, and proposed charger location to confirm the best plan and whether any earthing/PEN protection considerations apply (modern chargers usually have this built in).

Compatibility check: what does your car support?

A lot of EVs top out at 7–11 kW on AC, even if a 22 kW charger is present. Before paying for higher capacity, check:

Onboard AC charger rating (e.g., 7.4 kW single-phase, 11 kW three-phase, or 22 kW three-phase).
Future cars you may buy—many mainstream models still sit at 7–11 kW AC.

If your cars are 7 kW AC only, a 22 kW wallbox won’t accelerate home charging—put the budget into better features, load management, or solar integration instead.

Feature set that actually matters day-to-day

Reliable app + schedules: set/forget off-peak charging, see kWh and cost data.
Dynamic load management: protects your main fuse, keeps the house on.
Solar-aware modes: if you have (or plan) PV, allow solar-only or hybrid charging.
RFID / profiles: handy in shared driveways or to separate household vs guest charging.
Open standards (OCPP): optional future-proofing for billing/back-end changes (more relevant to flats/small business sites).

These features move the needle on cost, convenience, and safety far more than a higher AC rating you can’t exploit.

Costs & what determines them

Your total install cost depends less on 7.4 vs 22 kW, and more on:

Supply type: single-phase vs three-phase availability.
Cable route length/complexity (drill-throughs, external runs, trenching).
Consumer unit space & protection (RCBOs, RCD type, surge protection).
Connectivity (Wi-Fi solutions or 4G).
Extras (long tethered lead, solar integration, load management hardware if external to unit).

See guide ranges on our Pricing page. During a home survey we’ll pin everything down and give you a clear, itemised quote—no surprises.

Scenarios: which should you pick?

A) Typical EK homeowner, single-phase, one EV, commutes locally

Pick: 7.4 kW tethered, dynamic load management, off-peak scheduling.
Why: Fast overnight top-ups, lowest cost, simplest install.

B) Household with two EVs, single-phase, overlapping usage

Pick: 7.4 kW with smart load-sharing (two chargers or one dual-output unit) + off-peak schedule.
Why: Both cars can fill across the night window without tripping the supply.

C) New build or property with 3-phase already in

Pick: Consider 11–22 kW if your EVs support it and you truly need quick turnarounds.
Why: You already have the supply—make use of it if your cars can.

D) EV + solar PV user

Pick: 7.4 kW solar-aware unit with surplus-tracking and hybrid modes.
Why: Maximise self-consumption; use cheap grid hours only when needed.

Tethered vs untethered: quick decision grid

You value…	Choose	Why
Fastest daily plug-in	Tethered	Cable is ready—great in rain and after late drives
Clean façade / shared space	Untethered	Socket-only looks tidy; flexible for future cars
Multiple parking positions	Tethered (7.5 m)	Extra reach covers nose-in/tail-in
Frequent car changes	Untethered	Bring your own Type 2 cable

Installation process (what we handle)

Survey: confirm supply type, main fuse size, earthing, consumer unit space, Wi-Fi strength; measure cable route.
Design & quote: specify charger model, tether length, load management, extras (solar/4G), and provide an itemised price.
Install: neat cable run, correct protection, commissioning, app setup.
Paperwork: certification and any notifications; we’ll show you schedules and test buttons.
Aftercare: help with tariff optimisation and settings.

Learn more about the steps on EV Charger Installation in East Kilbride.

FAQs

Is 22 kW three times faster than 7.4 kW?
Only if your home is 3-phase and your car accepts 22 kW AC. Many don’t, so you’d see no benefit over 7.4 kW.

Will 7.4 kW be enough for winter?
Yes. Overnight windows are long enough to replenish typical daily miles, even in colder months—especially with smart off-peak tariffs.

Do I need a consumer unit upgrade first?
Not always. We’ll check spare ways, RCD/RCBO coverage, bonding, and surge protection. If upgrades are advisable, we’ll explain options and costs.

What if my Wi-Fi is weak at the driveway?
We can specify 4G versions or add a Wi-Fi extender so smart features work reliably.

Book a home survey

Still weighing 7.4 vs 22 kW? We’ll check your supply, car capability, cable route, and tariff options, then recommend the best-value setup for your home.

Explore options: EV Charger Installation in East Kilbride
Check guide costs: Pricing
Book a home survey: tell us your postcode, EV model, and where you’d like the charger mounted—we’ll come back with a clear plan and an itemised quote.