Why Is My EV Taking So Long To Charge?

Posted by John 17/03/2023 0 Comment(s)

How many of us have been in the position where you purchased an EV, the dealer has told you it will charge less than an hour and you get home only to find that it takes over 30 hours? There are reasons why your EV may not be charging as quickly as you would expect and it can be frustrating when you are not given the full facts by the dealer. It may be true that your car can get a full charge in under an hour, but there are different charging options available and some charge super fast while others charge, well, not so super fast! Below are a few explanations of why your EV may be taking more time to charge than you anticipated and, in some cases, how this can be improved.

Charge Capacity
All EV’s have a specific charge capacity when it comes to AC and DC charging. AC charging has three options: 1. Charging your vehicle using a Type 1 to Type 2 or Type 2 to Type 2 charging cable with a public charging point commonly found in supermarkets and retail parks where the charging point does not already have a cable attached to it, or with a wallbox that has been installed outside of your home. 2. Charging your vehicle using a 13a 3 pin socket that is commonly found in homes and offices, and 3. A CEE socket commonly found in industrial units, marina, campsites and some homes. AC charging can provide between 2.3 kw to 22kW and will typically charge your vehicle from 3 hours to over 30 hours.

However, the maximum current that your EV will accept will depend on the charging capacity that it’s Onboard charger can accept. So, if your vehicle can accept 7kW and you use a 22kW charging point, your vehicle will only charge at 7kW speed, which is 3 times slower than than the maximum speed that the charging point can provide. So, at 7kW, your vehicle will only ever receive up to around 20 miles of charge per hour. But, this depends on whether the charging point and charging cable you use can deliver at least 7kW current!

DC charging refers to the charging points you will generally find off major roads, in service stations and petrol stations. You can now also find them on streets and in some supermarkets. They are referred to as rapid chargers and these are the charging points where you can charge your vehicle in under an hour. They will already have a cable attached and the unit requires payment before you can use it to charge your EV. Your vehicle will have DC charging capacity if it has a CCS or CHAdeMO socket and it will typically range from 50kW to 250kW. Some models of the Kia EV6 can charge up to 233kW, which equates to around 650 miles of charge per hour, which is 10 times quicker than than what the fastest AC charging point can currently deliver.

To find out the charging capacity of your EV visit our Find my EV charger page. This will also recommend a the best suited charging cable for your vehicle.

The Right Charging Cable
Charging your EV can get a bit more complicated when you have an EV cable that can’t deliver the vehicles maximum charge capacity. When a 3 pin emergency/granny charger is used for example, because these only usually charge at 10A, this only equates to around 2,3kW and charging a full electric vehicle can take over 30 hours in some cases. Compare this to a Type 2 3 Phase 32A cable that can charge up to 22kW and you can see the difference between the charging capacity when different cables are used. To find the best fit charging cable for your vehicle, use our Find my EV charger page to see our recommendation.

What Current The Charging Station Can Deliver
A lot of cars on the market have a charge capacity of 11kW and the full 11kW can only be achieved with 3 Phase power, which is more common in Europe where homes are likely to have a 16A/11kW 3 Phase Wallbox. In the UK however 16A/11 kW 3 phase and 32A/22kW 3 Phase charging points are generally only seen in industrial locations or in retail carparks. If you are charging from a home Wallbox, this will likely be 1 Phase 32A, which has a maximum current of 7,4kW. 3 Phase charging cables need to be used to take advantage of 3 Phase charging point. A 3 phase cable can still be used with 1 Phase charging point and vice-versa, but the cable will only carry the maximum current that a charging point can provide and the cable is capable of carrying. For more information on 3 Phase charging please read our 3 Phase charging article

The Weather
Another reason your EV is charging more slowly than expected is when it is particularly cold outside. The perfect temperature at which to charge is between 15 and 35 degrees Celsius. So an EV battery does not like to charge in the dead of night during a cold snap. A couple of ways to combat this during winter is, if possible charge your vehicle when you’ve just got home so the battery is still warm or if you can park inside a garage where you can take advantage of a few degrees more of warmth. If you are travelling when the weather is particularly hot, this can also have an effect on the efficiency of the EV battery. The battery has to be kept at a certain battery temperature, so very hot weather will mean that the vehicle has to expend more energy in cooling the battery.

Trickle Charging
Something else that may make you believe your vehicle is charging too slowly is when your vehicle is Trickle Charging. If a batter is between 0-20% or above 80% full, the rate at which the vehicle charges slows down to protect the health of the battery and if you are using a fixed amp granny/portable charger the charge may stop charging at 80% because the cable cannot decrease the rate of charge going to the vehicle.

Scheduling Software
Most Electric Vehicles will have software that will enable you to schedule the charging of the the car to suit you. For example if you want to take advantage of lower cost of electricity during the midnight hours you can set a charging schedule usually via the vehicles App or via the console. However you will need to adjust this setting if you wish to charge outside your set hours. So if you start charging at 10pm and the EV is only set to start charging from 1am to 5am, it can cause some owners to think that the vehicle has been charging too slowly when they check the battery at 7am.

DC Charging
DC charging is the type of charge you receive via a CHAdeMO or CCS plug and the cable is tethered to the charging station. This is also known as a rapid charger. DC charging rates vary and usually span between 50 kW and 350kW. Your vehicle will also have a DC charge capacity, so a vehicles that has 200kW DC charging capacity will charge more quickly than a vehicle with 50kW capacity.

So in summary, there are a lot of variables to consider when charging your vehicle and it is a lot to take in. The main point when considering the speed at which your car can charge is the charging point, the charging cable and the vehicle itself. To help, we have a Find my EV charger page. But we are also on hand to answer any questions you may have - contact us.