22kW three-phase charging – is it worth it?
20th Feb 2020 Danny Morgan
Put simply 22kW three-phase charging is one of the faster chargers you can get at home or your workplace. But there are good reasons why you may not be able to have it and why it may not be worth having. This guide explains what 22kW charging is, if you can have it and whether you should.
What is three-phase 22kw charging?
You can charge your vehicle at home at a range of speeds depending on the power output of the charger. Starting from the lowest output, these typically include:
- Three-pin plug – 2.3kW
- Home charge point – 3.6kW
- Home charge point – 7.4kW (our recommendation)
- Home charge point – up to 22kW
A 22kW charger is the fastest charger you can get for the home, but to achieve this the charge point will use what’s called a three-phase supply.
Can I have three-phase 22kW charging?
This depends on two things:
- Does your property have a three-phase 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 supply. Most residential properties in the UK operate on a single-phase supply and therefore cannot make use of a three-phase 22kW charger.
This is why most EV drivers will have a 7.4kW charger installed at the property as this is the highest powered charger you can get on a single-phase supply. It is possible to arrange an upgrade to three-phase supply through your DNO, but this can be expensive with costs ranging from £3,000 to £15,000.
Can your car accept 22kW charging?
On top of this, most electric cars are unable to take advantage of three-phase 22kW charging at home. This is because they are limited to how much power they can accept for AC charging, which is the type of charging you will do at home or work using the Type 1 or Type 2 connection. It's the Type 1 and Type 2 part we are interested in - rapid charging uses a different connection (and DC charging to charge your vehicle) which is why most cars will rapid charge at 50kW or more.
For example, the Tesla Model 3 is limited to 11kW AC charging through its Type 2 connection (this does not apply to rapid charging). 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 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 we believe a 7.4kW charger at home is more than enough for overnight charging.
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 16kW 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 and the charger does not cost any more for the three-phase 22kW version, then it’s a no-brainer. You aren’t spending any more money and you’re gaining a faster charger.
Three-phase 22kW charging can be useful if you need to charge multiple EVs during the day. For instance, businesses may benefit from this if there are a handful of electric cars at the workplace and they are used regularly throughout the day.
A 22kW charger in this instance will mean the EVs are charged quicker, making it easier to “share” a charger at work.
Danny Morgan - editor at Smart Home Charge