Home versus public EV charging costs.

Home charging

Home charging commonly uses AC Level 1 or Level 2 equipment. The applicable utility rate may change by time of use, season, tariff, or household plan, so record the rate that applied when the session occurred.

Public charging

Public stations commonly use Level 2 or DC fast charging. A network may charge per kWh, per minute, per session, for parking, or through a membership, which makes the receipt total the safest comparison input.

A fair comparison

For each session, divide the final amount paid by delivered kWh. Then compare like periods and charging types. Separate AC and DC sessions because convenience, speed, and pricing often differ.

Account for charging losses

A home utility meter can record more energy than the vehicle reports as stored because charging equipment and battery conditioning consume energy. Use one measurement basis consistently and label it when sharing results.

Choose based on the full trip

Price is only one factor. Availability, charging speed, parking rules, route convenience, and the energy needed to reach another station can affect the practical choice.

Sources

• U.S. Department of Energy — Charging Electric Vehicles at Home
• U.S. Department of Energy — Charging Electric Vehicles in Public
• U.S. Department of Energy — Electric Vehicles for Consumers