EV Road Trip Charger Utilization Calculator

1. Enter daily session demand

Count the charging connections expected during a typical operating day.

2. Estimate energy per session

Use the average kWh delivered during one connection.

3. Set average delivered power

Use realistic average power rather than only charger nameplate power.

4. Define charger capacity

Enter charger count and the hours each unit is available.

5. Include connection overhead

Add non-charging occupancy such as parking, plug-in, and release time.

6. Review utilization and concurrency

Use average utilization together with simultaneous charger demand to assess capacity.

Session occupancy = Energy per session ÷ Average power + Overhead minutes ÷ 60 Daily charger demand = Sessions per day × Session occupancy Daily charger capacity = Chargers × Available hours per charger Utilization (%) = Daily demand ÷ Daily capacity × 100 Average simultaneous chargers = Daily demand ÷ Available hours

Utilization above 100% means the stated demand cannot fit into the available charger-hours without changing the schedule, power, or infrastructure.

What the result means

Utilization shows the share of available charger-hours consumed by the average daily demand.

Average utilization does not measure queue probability or short-duration peaks. Use time-of-day scheduling data for those questions.

Given: 86 sessions per day, 42 kWh per session, 105 kW average power, 8 chargers, 18 available hours, 6 minutes overhead, and 30 operating days.

Calculation: Session occupancy = 42 ÷ 105 + 6 ÷ 60 = 0.50 hour. Daily demand = 86 × 0.50 = 43 charger-hours. Capacity = 8 × 18 = 144 charger-hours. Utilization = 43 ÷ 144 × 100 = 29.9%.

Result: Average utilization is 29.9%, with about 2.39 chargers occupied on average during the window.