In this article, Phill Brookes-Maddicks, a qualified electrician at Indra, draws on his hands-on experience to explain one of the most common questions around EV charging - can you charge an EV using a regular 3-pin household plug, or do you really need a dedicated charger?
The aspect most frequently discussed among those considering EV ownership is the availability of charging. While the infrastructure for charging EVs is continually growing, most people still want the flexibility to charge at home.
At the end of August 2025, there were over 85,000 public electric charging points across the UK, of which 1,234 new devices had been added in August alone.
With so many wanting to jump onto the savings to be made by driving an electric vehicle, it’s hardly surprising that many are wondering why they can’t simply use a regular 3-pin household plug.
Well, let’s have Phill unpick this debate and outline the pros and cons.
"Firstly, let’s define it for clarity. A 3-pin charger is a portable charger that plugs into a standard 3-pin domestic socket with a type 2 connector at the car end. It’s sometimes called a ‘granny cable’ because you might use it in an emergency when visiting family (like your granny) without a charging point.
However, these types of chargers work on the maximum charge of a standard socket, 2.3kW, which means it’ll take a very long time to charge the vehicle. They are generally intended for very occasional use or emergencies, as they pull a great deal of power through the socket for hours at a time.
Unlike kettles, toasters or microwaves, which typically only draw power in short bursts, an EV requires ongoing and sustained maximum power for hours at a time, which is not what most sockets are designed to withstand."
"3-pin chargers can be safe if used occasionally, correctly, on modern wiring and meet manufacturer standards. 3-pin chargers are designed to meet strict electrical standards and tested before being supplied, so, of themselves, they aren’t unsafe.
Risks of regular use
However, using them to charge your EV regularly increases the risk if they are used in old or poorly wired sockets, which may be incapable of handling the continuous high draw of current needed to charge the vehicle over many hours. This can cause overheating and, in extreme cases, fire risk.
Domestic sockets appropriate for charging an EV should ideally be tested to BS 1363-2 and marked with “EV” on the back plate to ensure it is robust enough with proper contact resistance and thermal stability.
Standards and safeguards
The IET Wiring Regulations (Section 722) also provide essential safeguards by requiring it to be a dedicated circuit, have residual current protection (RCDs), and O-PEN fault protection, all of which help minimise the risk of overloading, earth faults or grid faults when a 3-pin plug is used.
Many installers and EV experts also advise limiting continuous charging loads to 10A for long sessions, as it will reduce the risk of overheating."
Extension cables: why they increase risk
"In the same way, using 3-pin plugs with extension cables or multi-plug adapters to connect your EV to the power introduces additional resistance and potential weak points in the circuit that can overheat under prolonged loads.
The length of time that it takes to charge a vehicle in this way keeps the plug and wiring under strain for longer periods, making them more susceptible to overheating.
With all that being said, a ‘granny’ plug used responsibly on up-to-date equipment and proper wiring installation can be a convenient backup when done in the right conditions."
"Having discussed the safety issues surrounding the 3-pin charger, let’s look at the pros and cons. The main advantages of using this type of charger include:
Accessibility
Every household has a 3-pin socket, so no additional installation is needed.
Convenience
It’s easy to carry and use anywhere with a standard electrical socket.
Cost-effective
No additional need to have a home EV charger installed.
Backup
It’s a great option for when you’re travelling or in an emergency.
"The main disadvantages of the ‘granny’ charger are:
Slow charging
Only adds around 6–8 miles of range per hour. A full charge could take 24 hours or more, especially for cars with larger batteries.
Potential overheating
Continuous high current can stress sockets and wiring — increasing the risk of melting, scorched sockets, or even fire hazards.
Not future proof
Fine for occasional use, but not practical for regular charging or bigger battery capacities.
Warranty or insurance issues
Some manufacturers caution that extended use of 3-pin charging may affect warranty coverage, so owners should always check their vehicle handbook.
No smart control
Unlike a home EV charger, which can integrate with smart features such as scheduled charging, load balancing, solar integration or off-peak tariffs, 3-pin chargers can’t offer money savings or reduce strain on the grid.
“EV-rated” sockets aren’t always cheaper
Even with an EV-rated 3-pin socket, regulations require O-PEN protection. This can make the cost similar to — or even higher than — installing a proper home charger.
O-PEN fault protection
Unlike dedicated EV chargers, standard 3-pin chargers typically don't include O-PEN fault protection. This is an important safeguard built into Indra chargers via our patented PEST™ technology.
Limited safety in older properties
Many older properties, particularly those built before 2008, may not have Residual Current Device (RCD) protection unless the wiring has been updated. Without it, plugging in a 3-pin charger leaves no safeguard against electric shock if a fault occurs. An electrician should always advise and check before relying on 3-pin charging.
"Using a 3-pin charger is safe as an overnight top-up in an emergency, with a modern, properly wired socket, good ventilation and avoiding extension cables. However, if you’re using an EV daily and need regular, reliable charging it’s time to upgrade to a dedicated EV home charger.
A home EV charger offers many benefits over the 3-pin charging option:
Faster charging
An Indra charger offers 7.4 kW charging, or up to 30 miles of range per hour, offering a full charge in a matter of several hours, rather than a day or more.
Safety
An EV home charger, especially an Indra one with our PEST™ technology, is fitted with safety features to safeguard you.
Smart features
With an Indra charger, you’ll be able to access the most cost-effective charging rates, schedule charging at the most convenient and affordable times and integrate solar power for greater savings."
So, according to Phill's expertise: using a 3-pin charger is safe for occasional charges when used with modern wiring and sockets, and a reduced charge rate. However, for long-term EV ownership, a dedicated charger is the safer, faster, more cost-effective and future-proof solution.
Those considering EV ownership should assess their driving habits and charging needs and select the best method for EV charging to suit these. Why not check out our quality range of domestic EV Smart chargers to enable safe charging on your doorstep?
This article is for general information only and does not constitute electrical or safety advice. Always consult a qualified electrician before using a 3-pin charger for your EV. Indra recommends a dedicated EV charger for regular use to ensure the highest levels of safety and charging performance.
 | About the author: Phill joined Indra in March 2022 as an Installer and Trainer after working for the Royal Air Force as an Avionics Technician for 12 years, and training as an electrician post-RAF. He is now the Sustaining Team Lead in Training and Installation. |
