3.6kW, 7kW, 22kW. The numbers get thrown around a lot when you’re looking into a home charger, often with the unspoken assumption that bigger is automatically better. In practice, the right speed for your home depends on your electricity supply, your car, and how you actually plan to use it, not on picking the biggest number available.
What limits your options before you’ve even chosen
The single biggest factor most people don’t realise matters is what kind of electricity supply their home actually has. According to RAC Drive’s guide to electric car charging speeds, the vast majority of UK homes have a single-phase electricity supply, which caps the realistic maximum for a home wallbox at 7kW. A 22kW charger needs a three-phase supply, which is genuinely rare in UK domestic properties and, where it’s not already present, can be applied for through your local network operator, though it’s a significant undertaking that’s rarely proportionate for an ordinary household.
In practice, that means most homes in Basingstoke, Old Basing, Chineham, Oakley and Sherborne St John are choosing between 3.6kW and 7kW, not between 7kW and 22kW. It’s worth knowing that upfront, so you’re comparing the options that are actually realistic for your property rather than being sold on a headline figure your supply can’t deliver anyway.
Your car’s onboard charger is the other half of the equation
Even with a fast wallbox installed, your car can only accept AC power up to whatever its own onboard charger is rated for, and this varies significantly between models. Zapmap’s model-by-model charging guides show just how much this differs across the market, some cars top out around 7kW on AC charging regardless of what’s on your wall, while others can accept 11kW or more if paired with a three-phase supply. Charging speed is always limited by whichever is lower, the charger’s output or the car’s own acceptance rate, so a faster charger than your car can use doesn’t get you anything extra.
This is worth checking specifically for your own vehicle, or the one you’re planning to buy, rather than assuming every EV behaves the same way.
What the difference actually feels like day to day
Numbers on a spec sheet don’t always translate into something meaningful, so it’s worth thinking about it in terms of your actual routine instead. If you typically plug in as soon as you get home in the evening and don’t need the car again until the next morning, both 3.6kW and 7kW will comfortably fill most batteries overnight, the difference is mainly in how much margin you have if you come home later than usual, need a top-up in the middle of the day, or occasionally need a bigger charge in a shorter window. For households with a tighter overnight schedule, or more than one EV sharing a single charger, that extra margin from 7kW tends to matter more in practice than the raw numbers suggest on their own.
Why 7kW has become the default, and when 3.6kW still makes sense
For most homes with a straightforward single-phase supply and reasonable spare capacity, 7kW has become the sensible default recommendation, roughly halving typical overnight charging time compared with 3.6kW, without requiring the kind of electrical upgrade that a three-phase supply would demand.
That said, 3.6kW isn’t automatically the wrong answer. If your existing consumer unit has limited spare capacity, if your household’s mileage needs are modest, or if you’re always charging overnight over a long window regardless of speed, a 3.6kW installation can be a perfectly sensible, lower-impact choice on your home’s electrics. The right answer depends on your actual circumstances, not on which number sounds more impressive.
How your chosen speed affects the paperwork too
The speed you choose doesn’t just affect how quickly your car charges, it affects how the installation gets approved. Under the notification framework used by Scottish and Southern Electricity Networks, our local network operator, installations up to 3.68kW per phase generally fall under the simpler G98 notification process, while anything above that threshold typically needs the fuller G99 application process, which takes longer and gives the network operator more scope to assess or query the connection.
Given the network capacity considerations already affecting parts of Hampshire, a higher-power installation isn’t necessarily a rubber stamp, it may need a more involved application and, in rarer cases, could be constrained by what the local network can accommodate. This is exactly the kind of detail that’s easy to overlook if you’re focused purely on charging speed.
Should you future-proof and go faster than you need right now?
It’s a fair question, and there isn’t a universal right answer. If you’re likely to add a second EV, or you’re already planning solar and battery storage that you’d want to charge from efficiently, it can make sense to install with some headroom rather than needing further work later. A household expecting to run two cars off a single charger point at different times of day, for example, often benefits more from the extra margin 7kW provides than a single-car household would.
Equally, paying for capacity you’ll never use, or triggering a more complex G99 application unnecessarily when a straightforward G98 notification would have done the job, isn’t a sensible trade-off either. It’s a bit like reinforcing a roof that was never going to need it, spending more upfront and taking on more process than the situation actually calls for. This is worth talking through properly with whoever’s doing the installation, rather than defaulting to the fastest option just in case, or the cheapest option just to keep things simple.
Why this needs a proper assessment, not a default answer
Because the right speed depends on your specific supply, your car, and your local network connection, it’s not something that should be recommended without someone actually looking at your consumer unit and your circumstances first. GU Solutions is a NICEIC Approved Contractor and Domestic Installer, and part of doing this job properly means assessing your actual electrics and talking you through what’s realistic, rather than defaulting to whichever charger happens to be easiest to install.
What to ask before you choose
Before committing to a charger speed, ask your installer whether your home has single-phase or three-phase supply, and what that means for your realistic options. Check your car’s onboard AC charging limit so you’re not paying for capacity it can’t use. And ask whether your chosen speed falls under G98 or G99 with SSEN, and what that means for how long the connection process might take.
Getting the right speed for your home
There’s no universally correct EV charger speed for every home in Basingstoke, Old Basing, Chineham, Oakley or Sherborne St John, because there’s no single supply, car, or usage pattern that applies to everyone.
If you’d like a recommendation based on your actual property and vehicle, GU Solutions is the first port of call. As NICEIC Approved Contractors and Domestic Installers, we’ll assess your supply properly and recommend the speed that genuinely fits, not just the biggest number on the price list.
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