What is a granny charger?
A granny charger is a portable EV charging cable that plugs into a normal UK 3 pin household socket instead of a wallbox. It has a control box part way along the cable that checks the supply and talks to the car. It charges slowly, at up to about 2.3kW, adding roughly 8 miles of range an hour, so it suits plug-in hybrids, lower mileage drivers, renters and anyone waiting for a wallbox to be fitted.
The name is a joke about speed, not age. It is slow and steady compared with a 7.4kW wallbox. But for a lot of drivers, slow and steady overnight is all they ever need.
Key points
- A granny charger is a Type 2 to 3 pin cable with a built-in control box, not a battery pack.
- It charges at up to about 2.3kW, adding around 8 miles of range an hour and about 80 miles over a 10 hour night.
- A plug-in hybrid fills up overnight. A big electric car takes more than a day from empty.
- Plug it straight into a wall socket in good condition. Never use an extension lead or cable reel.
- There is no safe "3 pin to Type 2 adapter". The control box is what makes charging from a socket safe.
Is a granny charger the same as a portable EV charger?
Usually, yes. In the UK "portable EV charger", "3 pin EV charger", "Type 2 to 3 pin cable" and "granny charger" all describe the same product: a cable that lets you charge from a household socket anywhere you can reach one.
The phrase "portable EV charger" is also used for battery power banks, which carry stored energy to a car that has run flat. Those are a roadside rescue product, they hold only a few miles of range and they cost far more. If you want to charge at home, at work or when you visit family, the cable is what you need.
How long does a granny charger take?
At up to 2.3kW, a granny charger adds about 8 miles of range for every hour plugged in. The table shows how long a full charge from empty takes for some popular cars. The figures include about 10% for charging losses, and a car rarely arrives home completely empty, so an overnight top up is what most drivers actually do.
| Car | Battery used for the sum | Empty to full on a granny charger | Range added in a 10 hour night (approx.) |
|---|---|---|---|
| Toyota RAV4 Plug-in (2021 to 2025) | 18.1kWh | 8h 30m | Full battery |
| BMW 330e (July 2024 on) | 19.5kWh | 9h 30m | Full battery |
| Mitsubishi Outlander PHEV (2019 to 2021) | 13.8kWh | 6h 30m | Full battery |
| Renault 5 E-Tech (Comfort Range) | 52kWh | 25h | About 80 miles |
| Vauxhall Corsa Electric (2023 on) | 49kWh | 23h 30m | About 80 miles |
| MG4 (Long Range) | 61.7kWh | 29h 30m | About 80 miles |
| Tesla Model Y (RWD) | 60kWh | 28h 30m | About 80 miles |
| Kia EV3 (Long Range) | 78kWh | 37h 30m | About 80 miles |
For more cars, and the same figures on a 7.4kW wallbox, see how long does it take to charge an electric car at home? The Mitsubishi Outlander PHEV of that age has a Type 1 socket, so it needs a Type 1 to 3 pin cable.
Is a granny charger worth it?
It depends on how far you drive. Around 80 miles a night covers most daily driving. The question is whether you can plug in most nights.
| You are... | Is a granny charger enough? |
|---|---|
| A plug-in hybrid driver | Yes. It fills a typical hybrid battery overnight, and many hybrids cannot charge much faster than 3.7kW anyway. |
| An electric car driver doing up to about 40 miles a day | Usually yes, if you can plug in most nights. |
| Renting, or waiting for a wallbox to be installed | Yes, as a stopgap. It needs no installation and moves house with you. |
| Visiting family, holiday lets or hotels without a charger | Yes. It is the best cable to keep in the boot for these trips. |
| Driving 60 miles or more a day with a big battery | Probably not as your only charger. A 7.4kW wallbox fills three times faster. |
A home wallbox costs roughly £800 to £1,200 fully installed. We break down the numbers in how much does it cost to install an EV charger at home? For a low mileage driver a granny charger does the same job for a fraction of that.
Is it safe to charge from a 3 pin plug every night?
Yes, if the socket and wiring are in good condition and you follow a few rules. A charging car draws a steady current for hours, which is harder work for a socket than a kettle or a hoover. That is why the rules matter.
- Plug straight into a wall socket. Never use a household extension lead, a multi-way adaptor or a cable reel, at any rating. Our guide to charging with an extension cord explains why.
- Use a socket that is in good condition, with no scorch marks, loose fit or crackling. If the plug gets more than slightly warm, stop and have the socket checked.
- If your wiring is old, or you plan to charge this way every night, ask a qualified electrician to check the socket and circuit. An outdoor socket should be weatherproof and RCD protected.
- Uncoil the cable fully and keep the control box off wet ground where you can.
- Don't run other heavy appliances from the same double socket while the car charges.
Our full safety guide, can you plug an electric car into a regular 13amp socket?, covers this in more depth. Leaving a car on charge overnight is fine and is what most drivers do. See can I leave my EV plugged in overnight?
Why not buy a faster 3kW granny charger?
Some granny chargers now draw the full 13A a household socket is rated for, which works out at about 3kW. That is roughly 30% faster than a 10A unit. We have chosen to supply 10A units instead, delivering up to 2.3kW.
A 13A plug and socket are rated for 13A, but a car charges for 10 hours or more without a break. Running a socket at its full rating for that long puts the most heat into the plug, the socket and any weak connection behind it. Drawing a little less gives a margin for the older and less than perfect sockets many drivers have. Over a 10 hour night the difference is roughly 20 to 25 miles of range. If you regularly need that extra speed, a 7.4kW wallbox is the better answer.
"We would rather a customer gets 80 miles a night from a socket that stays cool than 100 miles from one that is working at its limit every night of the year. If a driver needs more than that, the honest advice is a wallbox." Andrew Gillespie, Director, EV Cable Shop
Is there a 3 pin to Type 2 adapter?
Not a safe one. You may see small plug adapters sold as a "3 pin to Type 2 adapter" or "3 pin to car adapter". Do not use them to charge a car.
A car cannot be charged from a socket by the plug alone. The control box on a proper granny charger (its technical name is an in-cable control and protection device) checks the earth, protects against faults, and tells the car how much current it may draw. Without it you bypass every one of those safety checks. The safe way to charge from a 3 pin socket is a purpose-made Type 2 to 3 pin charging cable.
If your question is really "can I use my wallbox cable at a normal socket?", the answer is no for the same reason. A Type 2 to Type 2 cable only works with a charge point, which provides those checks itself.
What should you look for in a granny charger?
| Feature | What to look for | Ours |
|---|---|---|
| Connector | Type 2 for almost every car since 2018. Type 1 for older cars. | Type 2, with a Type 1 version for older cars |
| Standard | IEC 62752 for the control box, CE marked | IEC 62752, CE marked |
| Adjustable current | Lets you turn the current down on a socket you are unsure of | Adjustable, from 6A |
| Water rating | A high rating, because the control box rests on the ground | IP67, protected against temporary immersion |
| Temperature range | Works in a British winter | -30C to +60C |
| Length | Enough to reach the car without an extension lead | 5m, 10m or 15m |
| Warranty | At least 2 years from a UK seller | 2 year manufacturer's warranty |
Which length of granny charger do you need?
Measure from the socket to your car's charge port, following the route the cable will lie, and add a metre. Buy the length that covers it. You can never make up the difference with an extension lead.
| Length | Suits | Price |
|---|---|---|
| 5m | A socket in the garage or on the wall next to the car | £187.99 |
| 10m | Charge port on the far side of the car, or a socket inside the porch | £232.99 |
| 15m | Longer driveways | £279.00 |
Prices are correct at the time of writing (September 2026). Every cable carries our 2 year manufacturer's warranty and free next working day UK delivery. Keep it clean and dry in the boot with an EV charging cable bag.
Many of our car pages also sell the granny charger alongside the right Type 2 cable for that car, for example the Tesla Model Y, MG4 and Kia EV3 pages.
Granny charger or wallbox?
| Granny charger | 7.4kW wallbox | |
|---|---|---|
| Speed | Up to 2.3kW, about 8 miles an hour | 7.4kW, about 25 miles an hour |
| Cost | From £187.99 | Roughly £800 to £1,200 installed |
| Installation | None | Qualified electrician, sometimes a consumer unit upgrade |
| Portable | Yes, lives in the boot | No |
| Best for | Hybrids, low mileage, renters, travel | High mileage and big batteries |
Many drivers own both: a wallbox at home and a granny charger in the boot for everywhere else. If you have a wallbox with an untethered socket, you will also need a Type 2 to Type 2 cable.
Granny charger FAQs
Why is it called a granny charger?
Because it is slow compared with a wallbox. The name has stuck in the UK for any EV cable that plugs into a normal 3 pin socket.
How long does a granny charger take to charge a car?
About 8 miles of range for every hour at up to 2.3kW. A plug-in hybrid fills overnight in 6 to 10 hours. A 60kWh electric car takes about 28 hours from empty, though most drivers only top up what they used that day.
Can I use a granny charger every day?
Yes, if the socket and wiring are in good condition. Plug straight into the wall, never into an extension lead, and have an electrician check older wiring if you will charge this way every night.
Can I use an extension lead with a granny charger?
No. Never charge a car through a household extension lead or cable reel. Buy a granny charger long enough to reach the car.
How much does a granny charger cost?
Our Type 2 to 3 pin cables start at £187.99 for 5m, with 10m and 15m versions for longer runs.
Is there an adapter to charge an electric car from a 3 pin plug?
No safe one. You need a purpose-made granny charger with its built-in control box, which checks the supply and tells the car how much current it can draw.
