This estimator calculates the time needed to add energy to an EV road-trip charging stop. It limits charging power to the lower of the charger rating and the vehicle's acceptance rate, adjusts for charging efficiency, and adds fixed connection or queue time.
The result is useful for itinerary planning, depot scheduling, and comparing charger options. Real sessions can take longer because charge power usually tapers at high state of charge, battery temperature affects acceptance, and a public charger may not deliver its nameplate rating continuously.
Enter battery capacity, starting state of charge, and the target charge level.
Use the charger power available at the stop or depot.
Enter the maximum power the vehicle can accept.
Set charging efficiency and any queue, connection, or setup minutes.
Compare active charging time with the total window including overhead.
The model uses average effective power. It does not build a vehicle-specific taper curve, so charging near 100% may take longer than the estimate.
The main result is the complete charging window, including active energy transfer and the overhead entered.
Use a conservative power assumption when charger reliability, cold weather, or high-SOC tapering is material.
Given: 78 kWh battery, 18% start SOC, 80% target SOC, 150 kW charger, 170 kW vehicle limit, 92% efficiency, and 12 minutes of overhead.
Calculation: Battery energy = 78 × (80 − 18)% = 48.36 kWh. Grid energy = 48.36 ÷ 0.92 = 52.57 kWh. Effective power = 150 kW. Active time = 52.57 ÷ 150 = 0.350 hours. Total time = 0.350 + 0.200 = 0.550 hours.
Result: The estimated stop is 0.55 hours, or about 33 minutes.
The vehicle and charger form a constrained pair. The lower of the two power limits controls the estimate.
Not explicitly. Enter a lower average charger or vehicle power to represent tapering, especially for high target SOC values.
Include expected queueing, parking, connector setup, payment, safety checks, or depot handling that is outside active charging.
Yes. Enter the AC charger output and the vehicle's AC acceptance limit using the same kW unit.
Charging is not perfectly efficient. Conversion, cable, thermal-management, and battery losses increase energy drawn from the grid.