How Long Does A 7kW Charge Take
People often want to know the different charging speeds so they can plan their day around the charging schedule.
Most chargers at home are 7kW which means potential EV owners are usually curious about how long does a 7kW charge take?
In this guide, we’ll explain what sort of time you can expect for your car to charge with a 7kW.
Let’s get started…
How Long Does It Take To Charge To Full With 7kW?
Standard home chargers are usually 7kW but you can get slightly higher if your electric car supports the rate. A 7kW every hour will add about 25 miles of range to the battery.
So if you had a 50kWh battery which is what a typical electric car would have, this would take on average about 7-8 hours to fully charge the battery.
Although you shouldn’t do this as it can harm the battery in the long term, you are better off charging to 80% and then using your home electric vehicle.
Larger battery electric vehicles will take longer to charge and smaller batteries will take less time to charge. So if you had an 80kWh battery this would take about 10-12 hours to fully charge using 7kW, it would charge a lot faster if you were using rapid charging points though.
Difference Between 7kW, 7.2kW and 7.4kW Charging Speeds?
The battery in an electric vehicle is measured by the amount of energy it can hold and this is done in kilowatt-hours (kWh). Whilst the charging power is measured in kilowatts (kW) and the charging speeds themselves are determined through the charger and what output (kW) it produces.
You can see the different charging powers and the range you can expect to get per hour:
7kW – 20-25 range miles per hour
7.2kW – 25-28 range miles per hour
7.4kW – 28-30 range miles per hour
As you can see, if you’re using a 7kW charge, the car takes quite a few hours to reach its full capacity range.
What Factors Affect Charging Speed?
Charging speed is one of the main factors that people look at before purchasing an electric vehicle. Most EV owners have a home charging point as it offers convenience but in this section, we’ll look at what factors affect charging speed:
Depending on the charger, this will affect how quickly it takes your car to charge. If you have a 22kW, it’s going to charge a lot faster than a 7kW. Most public charging stations have rapid charge points which allow EVs to charge quicker, whilst homes usually have a maximum of 7kW.
Weather & Temperature
Extreme cold and heat can cause chemical reactions in the lithium-ion battery which slows the charging speed but more importantly, reduces the maximum range in an electric car. If it could once do 120 miles fully charged, after the temperature damages the battery, it may only be able to do 105 miles.
If your charger can’t get the required electricity it needs to charge your vehicle from the National Grid, then this ends up causing slower charger times. Electric car drivers tend to put their vehicles on charge at night when the grid is at its least busy when people are asleep. This should cause minimal disruption to your electric car charging routine.
Calculating How Long It Takes For Electric Car Charging
Learning how to calculate charge time can help plan your day so you can charge in the morning, evening or maybe even at night. As a general consensus, charging times are reduced by 2% for every .2 increase from 7.2kW to 7.4kW as an example.
You can calculate the charging time through this simple equation:
Battery Capacity (kWh) ÷ Charger Power (kW) x .9 = Charging Time (Hours)
The .9 is the power efficiency and we accounted for a 0.1 loss which is to be expected.
We hope this article helped with what to expect for a 7kW charger. They are by no way the quickest, but they are very popular for homes as they can charge over the course of a few hours and won’t damage your battery as some rapid chargers would.
A 7kW is ideal for plugging in overnight so by the time you wake up in the morning, the car will be charged and you can set about your day. You can also set a limit on when you want your battery to stop charging, this could take an hour or 6 hours, it all depends on when you are happy that the battery is charged enough.
For all of our answers to questions regarding an EV, see our main guides page.