Methodology and Assumptions
This page explains how Voltavena’s calculators work, what assumptions they use, and what the results mean.
All calculations are estimates. They are based on the inputs you provide and simplified physical models. Real-world results vary depending on vehicle condition, driving style, weather, and infrastructure.
Units and conventions
Energy is measured in kilowatt-hours (kWh). Power is measured in kilowatts (kW). Distance is measured in kilometres (km). Currency is based on your selected country. Charging losses are expressed as a percentage of energy drawn from the grid that does not reach the battery.
Charging losses explained
When you charge, some energy is lost as heat in the cable, charger electronics, and battery management system. Typical AC charging losses are 5–10%, while DC fast charging losses are generally lower at 3–5%. Voltavena applies losses to the grid energy, not the battery energy, so you see what you actually pay for.
Default values
All default values shown in the calculators are clearly labeled as examples. Electricity prices vary by provider, tariff, and time of day. Always enter your own tariff for accurate results.
Range estimation
The winter range estimator applies a user-specified consumption increase to account for heating, battery chemistry effects, and denser air. The speed adjustment accounts for higher aerodynamic drag at motorway speeds.
Charging time estimation
Charging time is calculated as energy needed divided by effective charging power, adjusted for efficiency. In reality, charging speed decreases as the battery fills up. DC fast charging in particular follows a curve that can significantly extend the time above 80% state of charge.
Solar charging
Solar EV charging is not free. The opportunity cost is the feed-in tariff you would have received for exporting surplus solar energy. Voltavena uses this opportunity cost as the effective price of solar energy.