Understanding and optimising the cost of charging your electric vehicle

The cost of charging an electric vehicle at home 

Charging your electric car at home is the best way to save time and money. It’s the easiest way of controlling the cost of charging your EV. 

A practical, economical solution 

Whether you use a standard wall socket or a dedicated charging point, such as a wallbox (charging point fixed to the wall), charging an EV at home offers many advantages – starting with convenience. 

It is also a highly economical charging solution since the price of electricity is the same as for your household appliances. So the cost of charging your EV at home is strictly linked to the contract you have with your electricity supplier. 

Calculating the cost of charging an electric vehicle at home 

The cost of charging to full capacity 

To estimate the cost of home charging, you need to apply the following formula:

Battery capacity in kWh x Price of kWh of your electricity supplier 

For example, for an entry-level Hyundai Ioniq 5 sporting a 58 kWh battery and an electricity tariff of 17p/kWh, the cost of a full charge at home is:
–> 58 x 17p = £9.86 

Cost for 100 miles

To calculate the cost of charging to travel 100 miles, instead of taking the battery into account, you simply need to take the consumption of your EV in kWh/100 miles (usually between 19 and 32 kWh).

Keeping the same example, charging a Hyundai Ioniq 5, which consumes about 30.5 kWh/100 miles, costs about £5.18/100 miles (30.5 x 17).

Handy tip: If you have a contract with off-peak hours, think about plugging in your EV when the mains supply is at its lowest tariff. Some EVs also have an integrated timer so you can programme when you want to start charging – a highly practical and time-saving feature. This advice is all the more relevant when considering EV charging in the context of the energy crisis.

The cost of charging an electric vehicle outside your home 

Paying at public charging stations 

Let us first have a look at the main means of payment available at charging stations:

• Charging badge: This is the most widespread means of accessing charging points – quite simply because nearly all charging stations are fitted with an RFID reader since they are inexpensive to set up. 
  
  Most charging networks have their own badge. To make things easier, mobility service providers (MSP) like Chargemap offer all-in-one solutions so that you can access several networks with a single card. For example, you can charge your EV at more than 230,000 charge points throughout Europe if you use the Chargemap Pass. 
  
  

• Mobile app or QR code: Some MSPs allow you to charge up without having an actual badge by using a mobile app and NFC technology on smartphones or by scanning a QR code directly at the charging station.
  
  

• Credit/debit card: Despite a multitude of requests from users, paying to charge your EV by credit/debit card remains extremely rare. In fact, equipping charging stations with point-of-sale (POS) terminals is very costly. This is why this solution can only be found at rapid charging stations located on major roads. The higher operational costs are met by the increased passage of vehicles and higher charging rates. However, small, local charging networks tend to opt for a simple RFID reader to enable access to their infrastructures. 
  
  

• Via the vehicle: This is a system whereby the vehicle communicates the necessary information directly to the charging station. For the moment, this device is only available with Tesla for superchargers. 
  
  
  

Pricing models 

The diversity of stakeholders involved in the charging ecosystem means charging rates can be confusing for new EV drivers. In fact, there are as many rates as there are charging networks. So let us have a quick look at the main pricing models used:

• Time-related pricing
  This system of pricing is broadly used to calculate charging by the minute or by the hour. The major asset here is to step up EV turnaround time by encouraging drivers not to stay plugged in longer than necessary. Your charging bill continues to clock up as long as your car is plugged into the charge point – even if you have reached 100% battery capacity. 
  
  

• kWh-related pricing
  In this instance, you only pay for the power you take on board. This system is becoming more widespread. It is fairer and more advantageous for EVs with a lower charging capacity. No matter how long you are plugged into the charge point, the invoice reflects the real amount of electricity injected into the battery. 
  
  

• Rate according to a time slot (e.g. day/night rate)
  
  

• A pricing combo
  Charging networks may apply a mixed pricing system that combines, for example, a rate per minute and a rate per kWh. 
  
  

You should bear in mind that some additional costs may also be charged, among others:

• A flat rate each time a charging session is initiated 
• Occupancy fee: overcharge applied after a certain period of connection to the charging station
• Parking fee: rate applied when the vehicle is fully charged but continues to be connected to the station
  
  

How much does charging cost in concrete terms?

It is impossible to estimate an average cost because several factors come into play when calculating the cost of charging. However, you should bear in mind that the cost of charging your EV at a public charging station will depend on the following:

• The maximum power rating delivered by the charging station: In most cases, charging at a rapid or ultra-rapid charging station is more expensive than at a slow/fast charging station.
  
  

• The MSP used: If you use a charging badge like the Chargemap Pass and/or an app to pay for your charges, the rates vary according to the service provider and the services on offer.
  
  

• When you plug in: Some networks offer better rates if you charge at night, for instance.
  
  

• Your subscription: You can also take out a monthly/annual subscription with an MSP to obtain preferential rates on certain networks, for example.  
  
  
  

Good practices to optimise your charging budget 

Check the charging rates before plugging in 

This is fundamental for public charging stations. Always think about consulting the charging rates of your MSP before plugging in your EV. Quite simply because pricing systems change over time.

Unplug your EV as soon as you can 

As we saw earlier, many charging stations invoice per minute with the aim of having a rapid EV turnaround time. So remember that charging time and connection time are not the same.

After a certain period of plug-in time, some networks like Belib in Paris apply a very high rate. So it is important not to forget to unplug your car if you want to avoid receiving a hefty bill. 

Opt for a charging station that is adapted to your EV’s needs 

To avoid unpleasant surprises on receiving your bill, it is essential to be familiar with the technical specifications of your electric car. 

Example: If you want to charge your EV at an ultra-rapid charging station that delivers 250 kW but your on-board charger can only take 50 kW, the charging process will automatically be slowed down. In other words, the charging station will adapt to your vehicle. The charging time will be much slower than for a more powerful vehicle, and so will not be optimised. If the pricing system is time-related, you will therefore pay more for a service from which your EV cannot fully profit. 

 

Do not stay plugged in beyond 80% battery capacity

Once again, if the pricing system is based on the charging time and you really do not need to top up beyond 80%, unplug your car at this point and your wallet will feel the difference. Generally speaking, you need at least as much time to charge from 80 to 100% as you need from 20 to 80%. 

Use Chargemap to filter free charging stations 

Last but not least, we advise you to profit all you can from our Chargemap filters by only displaying free charging stations. While they are becoming more of a rarity, they are still available in the car parks of major chains, supermarkets, cinemas etc. 

We hope that this article has given you a clearer idea of the factors impacting the cost of charging your electric vehicle. If you would like to find out more on the fundamentals of charging, consult our set of informative articles.

For easy charging everywhere in Europe,

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