EV home charging is the cheapest and most convenient way to keep an electric car topped up — most owners do around 80% of their charging at home. A 7kW wallbox quietly refills a typical EV while you sleep, usually for a fraction of what public chargers cost. Here's how the charger types compare, how long a charge really takes, and what it costs.
The 30-second version
- A 7kW wallbox is the sweet spot for home charging — it refills most EVs overnight.
- Charging on an off-peak tariff can cost far less per mile than filling up with petrol.
- A three-pin "granny" lead works in a pinch but is slow and not meant for daily use.
- Running an EV or hybrid? Keep it road-legal with an EV MOT in St Helens.
How EV home charging works
EV home charging simply means plugging your car in where you park at home and letting it charge overnight or through the day. There are three practical ways to do it, and they differ hugely in speed.
At the slow end is a standard three-pin socket (about 2.3kW), then a dedicated 7kW wallbox — the option most people fit — and finally a 22kW charger, which only works if your home has a three-phase supply that most houses simply don't have.
Charger types, charge times and cost
Tap through the three things that decide your EV home charging setup — the charger options, how long each takes, and how home charging stacks up against public charging.
Your three options
- Three-pin lead (~2.3kW) — plugs into a normal socket. Handy as a backup but slow, and not designed for charging a car every single night.
- 7kW wallbox — a dedicated home charger wired to its own circuit. This is what most owners fit and the natural choice for daily EV home charging.
- 22kW charger — three times faster again, but it needs a three-phase supply that the vast majority of UK homes don't have.
How long it takes
On a 7kW wallbox, most EVs go from low to full in roughly eight to nine hours — easily done overnight. A three-pin lead can take a full day or more for the same battery, which is why it suits topping up rather than charging from empty.
Bigger batteries take longer, and cold weather slows things down. The trick with EV home charging is that you rarely start from empty — you plug in each evening and top up the miles you actually used.
Home vs public: the cost gap
Charging at home is almost always cheaper than public charging, and the gap widens on a dedicated EV tariff. Rough, caveated ranges look like this:
- Home, off-peak EV tariff: roughly 7–10p per kWh overnight.
- Home, standard tariff: around the current price-capped unit rate per kWh.
- Public rapid/ultra-rapid: commonly 60–85p per kWh.
Prices move constantly, so treat these as a guide, not a quote — but the pattern holds: home wins comfortably.
Save the most with an off-peak tariff
The biggest EV home charging saving comes from a time-of-use tariff that gives you cheap electricity for a few hours overnight. Set the car (or charger) to only draw power in that window and you pay the low rate every time.
⚡ Which charging setup suits you?
A 7kW wallbox is ideal ✅
You're the perfect fit for EV home charging. A dedicated 7kW wallbox will refill your car overnight, and pairing it with an off-peak tariff keeps your running costs low. Keep your EV serviced and its tyres in good shape and you're sorted.
Wallbox plus an off-peak tariff
High mileage makes a 7kW wallbox and a cheap overnight tariff a no-brainer — the savings versus public charging add up fast. Lots of miles also means keeping an eye on your EV tyres, which wear differently to a petrol car's.
A three-pin lead may be enough
For low mileage and short trips, a three-pin granny lead could cover you, topping up slowly between drives. A wallbox is still faster and safer for regular use, so it's worth weighing up. Either way, keep your EV or hybrid healthy with a proper EV service.
Home charging is tricky — but there are options
Without off-road parking you can't easily fit a home charger, so you'll rely on public and on-street charging. Some councils offer on-street solutions, and workplace charging can help. Not sure what's best for your car? Get in touch and we'll talk it through.
Getting set up for EV home charging
A home wallbox must be installed by a qualified electrician — it needs its own protected circuit and usually a bit of paperwork with your network operator. It's straightforward, but not a DIY job.
There's help with the cost, too. If you rent, or own a flat, you may be able to claim the EV chargepoint grant towards a home charger. You can check the current schemes and eligibility on the government grants for low-emission vehicles page.
Never charge through an extension lead
If you use a three-pin lead, plug it straight into a wall socket — never a domestic extension reel or multi-way adaptor. They aren't rated for hours of continuous high load and can overheat. A dedicated wallbox removes the risk entirely.
EV home charging and battery health
Good news: everyday EV home charging is gentle on your battery. Slower AC charging generates less heat than rapid public chargers, so leaning on home charging actually helps the battery last.
Two simple habits help most: for daily use, set a charge limit of around 80% rather than always going to 100%, and try not to leave the car sitting for long periods at a very low or very high state of charge. Save the full 100% charges for the days you genuinely need the extra range.
Don't forget the rest of the car
An EV still needs servicing, brakes, and tyres looking after — and it still needs an MOT once it's three years old. Instant torque and extra weight mean EV tyres can wear faster, so keep an eye on them between charges.
EV service, MOT & tyres in St Helens
Charging sorted? We'll look after everything else. Book an EV & hybrid service, an EV MOT or new EV tyres — RAC & AA approved, Motor Ombudsman accredited.
Frequently asked questions
A home charge point is a wall mounted unit wired to your consumer unit that delivers alternating current to the car, where the onboard charger converts it for the battery. Most domestic units run at 7kW on a single phase supply, which suits overnight charging perfectly. The car controls the process and stops when it reaches the limit you set. For anything on the vehicle side, ring 01744 808586 or see our EV diagnostics page.
A 7kW home unit adds roughly 25 to 30 miles of range per hour, so a typical 60kWh battery goes from low to full in eight or nine hours, which is exactly what an overnight window provides. A three pin granny cable delivers around 2.3kW, adding perhaps eight miles an hour, and suits topping up rather than a full charge. Most owners rarely charge from empty. Our IMI Level 4 qualified technicians can advise at our St Helens workshop.
Cost is your electricity rate multiplied by the kilowatt hours you put in, so the tariff matters more than anything else. An off-peak EV tariff charging overnight can cut the running cost dramatically compared with a standard rate, and most cars and chargers can be scheduled to use that window automatically. Charging efficiency loses a small percentage on top. See our guide to charging in St Helens for the public alternatives.
A granny cable plugged into a normal socket works and is genuinely useful as a backup, particularly at a relative house or a holiday cottage. It should go into a dedicated socket in good condition rather than an extension lead or a multi-way adaptor, because it draws a sustained load for many hours. A dedicated wall unit is safer and far faster for daily use. Our EV team can check the vehicle side of any charging problem.
Installation is electrical work and must be carried out by a qualified installer approved for EV charge points, who will assess your supply, earthing arrangement and consumer unit before fitting. They also handle the notification to your distribution network operator. That side sits with an electrician rather than a garage. Everything on the vehicle side, including charging faults and onboard charger diagnosis, we handle. Get in touch through our contact page.
A 7kW unit is the standard domestic single phase installation and is more than enough for overnight charging. A 22kW unit needs a three phase supply, which most UK homes do not have, and the car itself must have a three phase onboard charger to make use of it. Many EVs are limited to 7kW or 11kW on AC regardless of the unit. Check your vehicle specification. Our EV department can confirm what yours accepts.
Public rapid and ultra-rapid chargers supply direct current straight to the battery, bypassing the onboard charger, and typically take a car from low to 80 percent in twenty to forty minutes. Charging slows deliberately above 80 percent to protect the pack. Rapid charging costs more per unit than home electricity and generates more heat. See our local charging guide and the charging fault page.
Charging to around 80 percent for daily use is easier on a lithium battery than sitting at full charge, and most cars let you set that limit in the menu. Save the full charge for days when you actually need the range. Leaving a car at very low charge for weeks is worse still. Manufacturers with LFP battery chemistry sometimes advise a periodic full charge instead. Check your handbook, or ask our EV technicians on 01744 808586.
Cold weather slows charging noticeably, because a cold battery cannot accept current as quickly and the car limits the rate to protect the cells. Preconditioning the pack while still plugged in, or on the way to a rapid charger, largely solves it. Winter range also drops because cabin heating draws from the same battery. Cars with a heat pump fare better. Read our used EV checklist for what to look for.
Type 2 is the standard AC connector on every EV sold in the UK for the last decade, used for both home and public AC charging. For rapid DC charging, CCS is the standard on nearly all modern cars, while some older Japanese models use CHAdeMO. Tesla vehicles use Type 2 and CCS in the UK. Knowing yours avoids arriving at the wrong post. Our Tesla charging page covers those models.
Charging faults usually sit in one of three places: the charge point and its supply, the cable, or the car onboard charger and charge port. Error codes at the unit point at the first two; a car that fails on every charger points at the vehicle. Damaged port pins and a failed contactor are common on the vehicle side. Ring 01744 808586 and our technicians will diagnose it, or see our EV charging fault page.
Battery health declines slowly with age, total energy cycled and heat, and how you charge influences all three. Regular overnight AC charging at home is the gentlest pattern; constant rapid charging to 100 percent in hot weather is the hardest. Modern packs with active thermal management cope far better than early EVs did. We can measure state of health directly. Book a reading through our EV diagnostics service.
Plug-in hybrids charge from the same Type 2 home units, though their batteries are much smaller so a full charge often takes only two to four hours, and many are limited to 3.7kW on AC. Most cannot rapid charge at all. Charging regularly is what makes a plug-in hybrid economical; used purely on petrol it carries the battery weight for nothing. See our hybrid diagnostics page for servicing and fault work.
Charging habits do not change the service schedule, but they do affect what we look at. Brake fluid, battery coolant, cabin filters and reduction gearbox oil all still need attention on time, and we read battery health at each visit so you can see the trend rather than a single snapshot. Tyres wear faster on any EV. See our EV servicing page or the main servicing section.