EV charging cost is not simply battery capacity multiplied by the electricity rate. Energy is lost during charging, and the amount of electricity drawn from the wall is usually greater than the energy stored in the battery.
Home charging calculation
Charging cost = wall energy × electricity rate
If 50 kWh must reach the battery and overall charging efficiency is 90%, roughly 55.6 kWh must be drawn from the wall. At $0.17/kWh, that session costs about $9.45.
Cost per mile or kilometer
For travel comparisons, combine electricity price with the vehicle's real-world energy consumption. Seasonal temperature, speed, heating, air conditioning and driving style can change efficiency.
Home versus public charging
Public charging may use a different per-kWh rate, session fee or time-based fee. Use the actual network price rather than your home electricity tariff when comparing public charging.
Inputs that matter most
- Energy actually added to the battery.
- Charging efficiency.
- Your current electricity tariff.
- Real-world vehicle consumption.
- Any public-network session or parking fees.