When buying a home electric car charger you will sometimes be given a choice between 7kW (or sometimes 7.4kW) and 22kW power outputs. The difference between the two is simple: the bigger the power output, the faster it will charge your car! Unfortunately, it is not as simple as just installing the biggest charger that you can get you hands on. The maximum power output that most UK homes are compatible with is 7.4 kW, which is why this is the default choice for many of our customers.
If you’d like to know more of the technical details around why this is, and the circumstances in which a higher powered charger can be installed, then please read on.
To work out if a 22kW charger can be installed, it’s important to understand the different types of electrical supply available in the UK.
The most common type of supply for UK homes is single-phase electricty. This is where there is a single live line providing power to your house. For most domestic purposes, such as powering your appliances and heating your home, single phase electricity is plenty! If you have a single phase supply then a 7kW charger is generally the highest power output that you can safely install. This will charge a typical electric car from empty to full in around 8-10 hours.
However, if your property needs more energy it may use three-phase electricity. This is where three live lines provide power – and quite simply, more lines equals more power! This type of supply is often used for powering industrial sites or large commercial premises, and therefore is much less common in UK homes. If you are lucky enough to have a three phase supply, then you can install up to a 22kW charger which will charge your electric car more quickly. (Provided your car doesn’t have a limit on its charging rate. For example, the popular Nissan Leaf is limited to a maximum 6.6kW charging rate, therefore using a 22kW charger will make no difference whatsoever!)
If you’re lucky enough to have access to three phase electricity, then fill your boots and install the biggest charger that you can. Particularly if you own a hotel, restaurant, or cafe, being able to give your customers the ability to charge up more quickly is a great perk, and frees up your charger more quickly for other customers to use.
But for the vast majority of UK households a 7kW EV charger is the highest power output that can be safely installed, and is therefore the default choice. This is still a huge leap forward from charging your electric car using a 3-pin plug (which provides a miserably slow power output of 2.3kW) and plenty to give most electric cars a full charge overnight. Trust us – nothing beats the feeling of waking up to a full ‘tank’ every morning!
If you’d like to learn more about different types of EV chargers, feel free to take a look at our other articles.
