Our post " Improve Your Knowledge of Electric Vehicle Batteries " explained the basics of electric vehicles (EVs) and their batteries: capacity, charging speeds, and how far a charged battery will take you.
Today we will look at the costs of charging EV batteries using popular vehicles as examples.
We'll start by introducing you to the main factors that affect your bill, and then show you how to calculate the costs depending on the type of charging station, the technical characteristics of your vehicle, and average charging prices.
What factors determine the charging price?
EPS battery capacity
As explained in our post "Improve your knowledge of electric vehicle batteries," the amount of energy a battery can store is measured in kilowatt hours (kWh).
For example, the 2025 single-motor Polestar 4 model has a battery capacity of 100 kWh, which can take you up to 482 kilometers on a single charge.
Typically, the larger the battery capacity, the longer it will take to charge, although this can be offset by other factors.
Charging station output current
The charging station's current (amperage) is the maximum amount of electrical current it can provide.
Combined with the supply voltage, we get the output current of the station, measured in kilowatts (kW).
This should not be confused with kilowatt hours (kWh), which indicate the amount of energy stored in the battery.
As an example, the ELNexus EV7 charging station is a popular Level 2 charging station with a maximum output of 7.4 kW. If you leave the vehicle plugged in for one hour, the station will add 7.4 kWh of energy to the battery. If you leave it plugged in for two hours, it will be 14.8 kWh, and so on.
EV charging capacity
A vehicle's charging capacity rating depends on the charger it has built in. No matter how fast the charging station is, it can't charge faster than the vehicle can accept energy.
For example, the Ford F-150 Lightning with extended range has a built-in charger that supports a capacity of 19.2 kW, which is faster than the output current of many Level 2 charging stations.
Alternating current (AC) vs. direct current (DC)
Level 2 charging stations use alternating current (AC), which is then converted to direct current (DC) by the vehicle's onboard charger before being sent to the battery.
DC fast charging stations (level 3) convert the current themselves and send it directly to the vehicle battery, significantly speeding up the charging process.
Billing methods
While many drivers focus on the number of minutes or hours their vehicle is plugged into a charging station, charging is increasingly being billed per kilowatt hour (kWh).
Example of cost calculation
Let's take for example the 2025 Nissan LEAF with a battery capacity of 40 kWh and an onboard charger with a capacity of 6.6 kW.
We pair it with an ELNexus EV7 Level 2 charging station, which has a maximum output current of 7.4 kW.
We calculate the time it will take to charge the battery from 0 to 100 percent by dividing the battery capacity by the capacity of the built-in charger or the output current of the charging station, whichever is less.
In this case, we will use the capacity of the built-in charger (6.6 kW).
Example 1 - Calculating costs per kWh: Price per kWh: 0.36 BGN.
For 40 kWh: 7.20 BGN.
Example 2 - Calculating hourly costs: 6 hours of charging time x 2.80 BGN per hour = 16.80 BGN.
