Charging an electric car from a standard 3-pin socket (Type G, the familiar UK/Ireland three-pin socket) is often where EV ownership starts. A granny charger can cover low daily mileage overnight, but only when the socket, wiring and charger are genuinely up to the job.
A granny charger is not a faster wallbox in a smaller box. It is a portable Mode 2 charger that draws a limited current from a normal socket, so the whole electrical path needs to be checked before it becomes a routine habit.
A granny charger suits low daily mileage and long overnight parking when around 2.3–3 kW is enough. It is a limited home-charging solution, not a permanent replacement for a properly installed home charger.
What a granny charger is
A granny charger is a portable charger that plugs into a standard household 3-pin socket (Type G, the familiar three-pin UK/Ireland socket) and connects to the car, usually with a Type 2 connector. It is the slow, convenient way to top up an EV without a dedicated home charger.
The socket matters as much as the charger. A standard 13 A socket was not designed for hours of continuous high load every day, so the circuit, the condition of the socket and the chosen current setting all affect safety.
In Ireland and the UK, this type of charging is commonly called a granny charger because it is the gentle, everyday option compared with a fixed wallbox.
Ireland does not have a single socket type in every home. Many houses use the Type G three-pin socket (the standard UK/Ireland plug), while some use European Schuko sockets. Before choosing a charger, check which socket type your home actually has.
3-pin (Type G) socket vs dedicated home charger
The right choice depends less on the name of the solution than on your daily mileage, the time the car is parked and the condition of the electrical installation. A 3-pin (Type G) socket suits limited, well-supervised use. A dedicated home charger suits regular charging at higher power.
| Solution | Power or current | Installation and checks | Most sensible use |
|---|---|---|---|
| Standard 3-pin (Type G) socket | Limited current depending on charger, circuit and rules | Check socket and circuit; use a cautious setting | Occasional charging or low mileage |
| Dedicated 3-pin (Type G) circuit | Around 2.3–3 kW / 10–13 A | Dedicated circuit and suitable RCD protection | Regular overnight top-ups at low power |
| Home wallbox | Higher, variable power depending on model, supply and car | Fixed installation with dedicated sizing | Higher power, faster charging or multiple cars |
When a granny charger makes sense
A granny charger works best when you drive modest daily distances and the car can stay plugged in overnight. At roughly 2.3–3 kW, a long overnight session can add enough energy for many short commutes, depending on the car.
It also suits drivers who want to keep a portable charger in the boot. The same unit can be used at home and carried to other places where the socket and supply have been checked.
It reaches its limits when you need to recover a lot of energy in a short time, when several cars share one socket, or when you want scheduled charging, faster speeds or connected features. In those cases a dedicated home charger is the better fit.
Safety checks first
The installation must be assessed as a whole. The rating printed on a socket or charger does not prove the house can deliver that load safely every night.
Before relying on a granny charger, a qualified electrician should check the consumer unit, whether the circuit is dedicated, the RCD protection, the earthing, the cable route and the condition of the socket. Never use extension leads or multi-socket adaptors.
Local wiring rules require a dedicated circuit and suitable protection for a charging point. Rheidon recommends having the installation checked and fitted by a qualified electrician.
Once in use, keep an eye on the socket. An old, loose, damaged, discoloured or unusually warm socket must not be used for regular charging. Plug the charger directly into the intended socket.
Power and current
Current and power are linked by P ≈ U × I. At 230 V, 10 A gives roughly 2.3 kW and 13 A gives roughly 3 kW. The actual figure is always set by the weakest part of the chain: the supply, circuit, socket, charger, the car's onboard charger, battery state and vehicle settings.
Choose the current according to the available installation, not only the charger's maximum. A lower setting is usually required on a standard socket, and continuous 13 A loads need a circuit that is genuinely rated for them.
Charging cable or portable charging station
The EV charging cable and portable charging station must respect the same limits as the socket and circuit. Before focusing on maximum power, check the plug type, the vehicle connector, the available current levels and the built-in protection.
For a Type G 3-pin socket, choose a portable charger with a compliant three-pin UK/Ireland plug, adjustable current and temperature monitoring at the plug. If your home uses a European Schuko socket instead, match the charger to that socket type. Unusual heat can signal poor contact or a socket that is struggling with the load.
Built-in RCD protection and protective-conductor monitoring complete the setup, but they do not replace a dedicated circuit or the protection in the consumer unit. Check Rheidon's portable charger range for the correct plug and current settings for your home setup — the PC200 Pro multi-adapter system includes a Type G adapter option, so one portable charger can cover the UK/Ireland three-pin socket and other socket types when you travel.
Socket or wallbox
A 3-pin (Type G) granny charger and a wallbox are two levels of the same need, not opposing ideas. The granny charger prioritises convenience, a familiar plug and a portable unit. A wallbox is a fixed installation with more power and better scheduling.
A granny charger can be enough when the car is parked for many hours, overnight charging covers your usual journeys and only one car uses the point. A wallbox is more relevant for higher mileage, shorter charging windows, multiple cars or smart features.
In both cases, the electrical design comes before the product choice. A wallbox does not create available power on its own, and a granny charger does not make a standard socket safe for continuous high current.
Cost of charging an EV at home
The cost of charging an EV at home depends mainly on your electricity tariff and how much energy you add each session. Home charging is usually cheaper than public fast charging, but the exact amount varies with your supplier and time-of-use plan.
If you are also considering a dedicated home charger, the installed cost depends on the consumer unit, the distance to the parking space, cable routing, earthing and any extra work. Two homes can therefore have very different quotes for the same product.
The most useful comparison is a detailed quote that separates the charger, protection, cabling, labour and any additional work. That lets you compare a granny charger against a wallbox on the full need, not just the sticker price.
Frequently asked questions
Can I charge an EV from a normal 3-pin (Type G) socket?
Yes, for occasional low-current charging, but a standard socket is not a permanent high-power solution. If your home has European Schuko sockets instead, the same principle applies: match the charger to the socket type. The socket and circuit should be checked by a qualified electrician before regular use.
How fast is a granny charger?
Typically around 2.3 kW, so it adds roughly 2.3 kWh per hour. Overnight this can cover many short commutes, depending on the car's efficiency and battery.
How much does charging an EV at home cost?
It depends on your electricity tariff and the energy added. Home charging is usually cheaper than public fast charging, but check your supplier's unit rate and any cheaper night-time tariff.
Do I need an electrician to use a granny charger?
Yes, it is worth having the circuit and socket checked. Local wiring rules require a dedicated circuit and suitable protection for a charging point.
Can I use an extension lead?
No. Extension leads and multi-socket adaptors add resistance and heat. The charger should plug directly into a socket that has been checked for the job.
Is a granny charger enough for overnight charging?
It depends on your daily mileage and the car's efficiency. If around 2.3 kW over your available parking time covers the energy you use, it can be enough.
What if the plug or socket gets unusually hot?
Stop charging and do not use that socket again until it has been checked. Unusual heat, smell, discolouration, looseness or repeated cut-outs need attention from an electrician.
How to decide
Before relying on a granny charger, ask three questions:
- Is the circuit dedicated and properly protected?
- Does around 2.3–3 kW cover your daily mileage during the parking time?
- Does the charger respect the limits of the socket, installation and car?
If the answers are yes, a granny charger can be a practical first step. Check Rheidon's portable charger range for the right plug for your socket type — Type G three-pin or Schuko — and confirm the installation with a qualified electrician before making it a daily habit.
Sources and references
The technical and product information in this guide is drawn from the following sources. Local electrical rules should be confirmed with a qualified electrician before any installation.
- Rheidon — portable chargers: plug options, integrated protection and use on a household socket.
- Rheidon guide — the difference between a portable charger and a fixed home wallbox.
