What is a granny charger?
It is a charging lead with a control box part way along, properly called a Mode 2 portable charger. One end plugs into a socket, the other into the car. The control box talks to the car, checks the earth and only switches the power on once everything is connected.
It gets the nickname because it is the slow, dependable option you fall back on. Most have a Type 2 car plug, which fits almost every EV sold new in the UK since 2018, Tesla included. Older Type 1 cars, such as the 2011 to 2017 Nissan Leaf and the Mitsubishi Outlander PHEV, need the Type 1 version.
How fast does a granny charger charge?
At 10A, a UK 3-pin granny charger delivers about 2.3kW. A 10 hour night adds about 23kWh, which is roughly 70 to 80 miles in a typical EV. For most commutes that keeps the car topped up. If you drive 100 miles a day, it will not keep up.
| Battery | Example | Time on a 3-pin granny charger |
|---|---|---|
| 14kWh, empty to full | Plug-in hybrid | about 6 hours |
| 40kWh, 20% to 80% | Nissan Leaf 40kWh | about 10 hours |
| 60kWh, 20% to 80% | Most mid size EVs | about 16 hours |
| 77kWh, 20% to 80% | Kia EV6, VW ID.4 Pro | about 20 hours |
Those are the energy divided by 2.3kW. Real times run a little longer, because some energy is lost as heat, and charging slows as the battery nears full. Our car guides give the charging time for 97 popular models.
Is a granny charger safe?
Yes, used properly. A good one limits itself to 10A on a UK plug, because a 13A plug can carry 13A for a while but runs hot at that current for hours. Better ones also watch the temperature of the plug and cut back if it warms up.
- Plug it straight into a wall socket. Never use an extension lead, a cable reel or a multi-plug adaptor.
- Use a socket in good condition. If the plug or socket ever feels warm, stop and have it checked.
- If the house wiring is old, have an electrician check the circuit before you rely on it every night.
- Outdoors, use a proper weatherproof socket protected by an RCD, fitted by an electrician. Do not run the lead through a window or a door that closes on it.
- Keep the control box and the household plug off the ground and out of puddles.
If the cable will not reach, buy a longer granny charger rather than an extension lead. Ours go up to 30m, and our long charging cables page explains how to measure.
Granny charger or a wall box?
| Speed | What it needs | Best for | |
|---|---|---|---|
| UK 3-pin granny charger | About 2.3kW, 8 miles an hour | A wall socket in good condition | Plug-in hybrids, short commutes, a backup |
| Commando granny charger | Up to 7kW, 24 miles an hour | A 32A commando socket | Workshops, yards, holiday lets, fleets |
| Home wall box | 7.4kW, 25 miles an hour | An installer to fit it | Daily charging at home |
A 7.4kW wall box charges about three times faster and is the better choice if you drive any distance every day or have a big battery. A granny charger needs no installation and goes wherever there is a socket, so it stays useful as a spare after a wall box goes in: for visiting family, a holiday cottage, or the day the wall box needs a repair.
Commando and Schuko granny chargers
A commando granny charger has a blue 32A plug and charges at up to 7kW, close to a wall box, wherever a commando socket is already fitted. That makes it handy in a workshop, a yard, a farm or a holiday let. If you are fitting something new at home anyway, a wall box is the better job.
A Schuko version has the round two pin plug used across most of Europe, for taking the car abroad, and draws up to 13A.
What to look for when you buy a granny charger
- The right car plug. Type 2 for almost every car since 2018, Type 1 for older Type 1 cars.
- A 10A limit on the UK plug, or a current setting you can keep at 10A.
- Plug temperature monitoring, so it cuts back if the plug heats up.
- A length that reaches without an extension lead. Measure from the socket to the charge port along the ground and add a metre or two.
- A weatherproof control box and a lead you can hang up rather than leave on the floor.
- UKCA or CE marking, and a seller who tells you who built it.
Our granny charger is built to order in the UK by Wottz, with a Type 2 or Type 1 connector, a UK 3-pin, Schuko or commando plug, lengths from 2m to 30m and plug temperature monitoring built in. In October 2026 the 3-pin Type 2 version is £160.37 for 2m and £178.19 for 5m, including VAT.
Granny chargers and Teslas
UK Tesla Model 3 and Model Y cars have a Type 2 socket, so any Type 2 granny charger fits. It charges at the same 2.3kW from a 3-pin plug as it would on any other car. For public posts, a Tesla needs a Type 2 charging cable.