The Risks of Charging Your Electric Vehicle with a 13A Plug in the UK
Charging an electric vehicle in the UK with a standard 13A plug can be dangerous and inefficient. Learn about the risks like fires and slow charging compared to proper EV chargers.
The adoption of electric vehicles (EVs) in the UK is skyrocketing, with around 810,000 electric vehicles and 1,325,000 plug-in hybrid vehicles currently on the roads as of July 2023. As more people make the switch to electric, questions about charging options are becoming increasingly common. One question that often arises is whether it's safe and efficient to use a standard 13A plug, also known as a "granny charger", to charge an EV. In this article, we'll explore the potential risks and drawbacks of using a 13A plug for EV charging and discuss safer, more efficient alternatives.
Understanding 13A Plugs
A 13A plug is a standard three-pin plug used in the UK for domestic appliances. When it comes to charging EVs, most manufacturers supply the vehicle with a three-pin domestic plug that you can plug into a normal socket. While it's entirely possible to charge an EV from a regular socket, it isn't necessarily the best option.
The Dangers of Using a 13A Plug for EV Charging
Overheating
A 13A plug can supply 13A for short periods of time, but it may overheat if that amount of current is drawn for longer periods of time. This could potentially lead to damage to the plug or socket, or even a fire.
Understanding the Overheating Risk
A standard 13A plug is designed to supply 13A of current for short periods of time. However, when charging an EV, this level of current is drawn continuously for several hours. This prolonged high-current draw can cause the plug and socket to heat up significantly. If this heat is not dissipated effectively, it can lead to damage to the plug or socket, or in extreme cases, it could even cause a fire.
Factors Contributing to Overheating
Several factors can contribute to overheating when charging an EV from a 13A plug. These include the quality of the plug and socket, the condition of the wiring, and the ambient temperature.
Cheaply made plugs and sockets may not be able to handle continuous high-current loads effectively. Over time, the contacts within these components can degrade, leading to poor electrical connections and increased resistance, which in turn leads to more heat generation.
The condition of the wiring can also play a significant role in overheating. Old or damaged wiring can have higher resistance, leading to increased heat generation. Similarly, if the wiring is not rated to handle the current draw of the EV charger, it can overheat.
Ambient temperature is another factor to consider. If the plug and socket are in a hot environment, they may not be able to dissipate heat effectively, leading to an increased risk of overheating.
Slow Charging
Charging an EV from a regular 13A socket is slower compared to using a dedicated EV charger. The power rating of a 13A plug is around 2.3 kW, which is significantly lower than the power ratings of dedicated EV chargers, which can range from 3.7 kW to 22 kW for AC chargers, and from 50 kW to 350 kW for DC rapid chargers.
Inadequate Infrastructure
The use of a 13A plug for charging is often due to a lack of dedicated EV charging infrastructure. This can lead to unsafe practices, such as using extension leads not suitable for outdoor use, or "daisy-chaining" extension leads to reach the vehicle.
The Benefits of Dedicated EV Charging Points
While a 13A plug can be used in a pinch, a dedicated EV charging point is a much safer and more efficient option. Here's why:
Faster Charging
Dedicated EV charging points offer faster charging speeds compared to a 13A plug. Depending on the type of charger and the vehicle's battery capacity, a dedicated EV charger can fully charge an EV in 4-6 hours, compared to 8-12 hours with a 13A plug.
Safety
Dedicated EV charging points are designed to handle the load of an EV, reducing the risk of electrical faults and fires. They also come with built-in safety features such as overcurrent protection and ground fault circuit interrupter (GFCI) protection.
Cost Savings
Charging an EV at home using a dedicated EV charging point can be more cost-effective in the long run. The Office of Low Emission Vehicles (OLEV) offers a 75% grant of up to £500 on the charging station installation costs, and some electricity providers offer special plans for EV owners that allow you to charge your EV for as low as 4.5 p per kWh during off-peak hours.
Convenience
Having a dedicated EV charging point at home means you can charge your EV whenever you want, without having to drive to a public charging point. It also means you can take advantage of off-peak electricity rates to save on charging costs.
Conclusion
While it's possible to use a 13A plug to charge an EV, it's not the safest or most efficient option. Installing a dedicated EV charging point at home can provide faster charging, improved safety, cost savings, and greater convenience. If you're considering making the switch to electric, it's worth investing in a dedicated EV charging point for your home.
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Hi - was reading this with interest and would like to comment on a few matters. I agree it is possible for sockets to overheat, but the article is alarmist and non specific to EV charging. I can't find any examples of where charging an EV from a socket has actually caused a problem. Many examples of poorly wired 13Amp (or more) heaters causing socket damage or worse, but nothing from EV charging at a steady 10 Amps which in my experience is not even causing the socket to get warm at all.
I decided against installing a "fast" charger for my Tesla Model Y. Instead, I had a professional install of an "EV rated" external socket to an RCD protected spur. In my instance I don't require PEN Fault protection, but my electrician explained, it would have been easy to add for a difference of £80 or so if it was needed. I now have a very safe, external socket I use to add as many miles as I can ever need (adds 9 miles per hour plugged in) - normally I don't even need the 6 hours on Intelligent Octopus to top up to 80% so a 7kw charger would be pointless (for me). If I am low % or need to charge to 100% for a trip I simply plug in earlier and the best bit is every time I have done this, those lovely people at Octopus give me additional hours at 7.5p to ensure I still reach my target % by the target time set in their app. And yes, my whole house is billed at the super low rate for those hours too.
Perhaps not the solution for someone who drives 100 miles a day, but for the majority of us who drive only a couple of 100 miles a week, charging via a professionally fitted 13Amp socket is a way to say £100's on the cost of a charger install AND you get more low price hours if you are on the Smart Octopus Tariff too. and no, I'm no affiliated with Octopus, but a huge fan of slow charging and if not familiar with Octopus IO, feel free to give it a try via their friendly affiliate link https://share.octopus.energy/snow-ibis-885 (we both get £50 bill credit if its used)