22kW three-phase charging at home – can you have it?
20th Feb 2020 Danny Morgan
The vast majority of UK residential customers can't have three-phase charging at home and, even if it's possible, is it really worth it? This guide explains what 22kW charging is, if your home has the capability and whether you even need it.
What is three-phase 22kw charging?
You can charge your vehicle at home at a range of speeds depending on the power source and output of the charger. Starting from the lowest output, these typically include:
- Three-pin plug – 2.3kW - Very slow
- Home charge point – 3.6kW - Slow
- Home charge point – 7.4kW - Fast (our recommendation)
- Home charge point – up to 22kW - Fast
A 22kW charger is the fastest charger you can get for the home, but to achieve this the charge point will need to be three-phase compatible and use what’s called a three-phase electricity supply. In addition, the car itself will need to be able to accept 22kW.
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Can I have three-phase 22kW charging?
This depends on two things:
- Does your property have a three-phase electricity supply?
- Can your car receive up to 22kW (AC)?
In order to charge a vehicle at 11kW or higher (such as 22kW), your property will need to have a three-phase electricity supply. Most residential properties in the UK operate on a single-phase supply and therefore cannot make use of a three-phase 22kW charger. It is possible to apply for an upgrade to three-phase supply through your DNO, but this will be very expensive with costs ranging from £3,000 to £15,000.
This is why most EV drivers will have a 7.4kW charger installed at the property as this is generally the highest powered charger you can get on a single-phase supply.
Can your car accept 22kW charging?
On top of this, the vast majority of electric cars are unable to take advantage of three-phase 22kW charging at home. This is because your car choice will determine how fast it can charge at home. A more powerful charger does not necessarily mean your car will charge faster.
For example, the Tesla Model 3 on-board charger limits the charging to 11kW AC through its Type 2 connection. This means that even if you had three-phase supply at home and a 22kW charger installed, a Tesla Model 3 in this instance would still only charge at 11kW.
Some vehicles have an even lower limit. For example, the new Nissan Leaf on-board charger is limited to 6.6kW charging at AC (as an optional upgrade on the car). This means that even with a 7.4kW charger this Nissan Leaf would charge at a maximum of 6.6kW.
Each car is different, so check with the manufacturer or dealer to find out how fast it can charge at home. In most situations our customers find a 7.4kW charger at home is more than enough for their needs.
Is three-phase 22kW worth it? Our editor’s take
In a word – no.
Most properties don’t have three-phase supply, plus it’s expensive to have it installed. Additionally, most electric cars can’t take full advantage of a 22kW charger at home anyway.
Even if you had three-phase already and your car could charge at a higher output, such as between 11kW or the full 22kW, the benefits are slim in my view. That’s because most charging takes place overnight.
Imagine charging your smartphone with a more powerful charger overnight while you’re asleep. It may well charge in one hour instead of two, but in both scenarios your phone will be fully charged when you wake up at 7am. You won’t have noticed the time saving.
For most drivers who will be merely topping up their vehicle every other night, for example, a 7.4kW charger is more than adequate.
When is it worth it then?
If you have three-phase supply at home already then a three-phase charger is an option. However, they will cost you more money due to the unit and installation both being more expensive.
Three-phase 22kW charging can be useful if you need to charge multiple EVs. For instance, if there are a few electric cars at home it might give you a few more charging options.
A 22kW charger in this instance will mean the EVs are charged quicker, making it easier to “share” the charger.
Danny Morgan - editor at Smart Home Charge