Is A 22kW Charger Faster Than A 7kW?

You will often find different kW chargers when charging your EV. If you are out in public using a charge point, they may be up to 50kW. Compare this to your average home charger, which may be 7kW.

It’s important to know the key differences, how they affect your charging rate and what sort of length of time it will take to charge your EV using a 7kW and a 22kW.

Charging Rate

car being charged

Your charging rate is simply how quickly your EV can charge using a certain size kW charger. 

There are three types of charging speeds:

Slow Charging 

These usually take 6-12 hours to charge your EV and can only reach a maximum of 3.6kW. You don’t often see a lot of these as they are just too slow for the everyday owner.

Fast Charging

This is where home charging ranges are. They start at 7kW and go right up to 22kW, depending on other factors. You will see these types of charge points at houses and public points. 

Rapid/Ultra Charging

You will only normally see these at supermarkets, motorway services, shopping centres and places like that. You can get power outputs ranging from 50kW up to 350kW, which would charge your EV in less than 30 minutes.

7kW vs. 22kW

The most obvious difference between the two is the speed at which it can charge your EV battery. A 22kW charger will be a lot faster than a 7kW. You can expect to get about 80-90 miles of range in an hour when charging with a 22kW. Compare this to a 7kW, where you are likely to get 25-35 miles of range in the same time period.


Secondly, you only need a single-phase electrical supply to install a 7kW, whilst you need a 3-phase electrical supply to install a 22kW. The single phase only has one live wire, whilst the 3 phase has three live wires.

Factors That Affect Charging Time

Discussion of the factors that affect the charging time of an EV, including the size of the battery, the charging rate, and the efficiency of the EV.

When charging your EV, you have to take into consideration the different factors that may affect the charging speed time. Below are some of the ones you need to remember: 

  • Battery Size – This is one of the major factors, as the larger the battery, the longer the charging time will be. 
  • Empty Battery – You never really want to let your battery go below 20% as it takes longer to charge from empty and it’s not good for the health of the battery in the long run.
  • Maximum EV Charging Rate – Some vehicles only accept a certain charging rate, so if your EV has a 7kW maximum charging rate, it won’t charge any quicker using a larger 22kW charger. 
  • Charge Point Rate – This is also the same if you were able to charge your EV at 11kW but were only using a 3.6kW, it would only charge at 3.6kW

 

This is why it’s important to get all the necessary information about the EV and the type of charger you want before making any decisions. It would be no good to have a 22kW charger installed if your EV only has a maximum rate of 7kW.

How To Calculate Charging Time

Below is a simple equation which will give you a rough estimation of how long it will take to charge your EV:

Charging time (hours) = battery energy added (kWh) ÷ charger power (kW)

Which Charger Is Faster?

There’s no doubt that the 22kW power output will charge your EV much faster than a 7kW. A 7kW will typically charge an EV in 4-6 hours, whilst a 22kW can achieve the same result in 1-2 hours. 

It all depends on the model of EV you have purchased, as we spoke about before, factors such as battery size, this will affect the charging time. So if you go for an EV with a much larger battery than say, a city car that has a smaller battery, this will drastically affect the charging times between the two.

Other Considerations

It’s worth noting that although a 22kW will charge much faster, you do have to take into account the costs involved and they will certainly be higher than if you were using a 7kW charger. 

Not to mention the upfront costs of having a 22kW installed with its three-phase power supply and the energy consumption it uses, these are certain points people forget when comparing the two.

Conclusion

We hope this guide helped you understand that a 22kW is undoubtedly faster than a 7kW, but the actual charging time depends on several factors, from battery size to the charging rate itself. Now that you are aware of all of this, it will make your decision a little bit easier when deciding whether to go with a 7kW or 22kW charger.

Take a look at more articles for electric vehicles on our main page where we dive into a range of questions our customers ask. 

Callum
Callum

Callum is the proud owner of a Nissan Leaf and is an EV fanatic. He has been featured in notable publications like USA Today and The Times for his expertise in the field.