What is the Difference Between Session Duration vs. Charging Duration?

When analyzing charging data, it’s important to know the difference between session duration and charging duration. While related, these two metrics measure different things and can affect how you evaluate charger utilization and vehicle readiness.

Session Duration

• Definition: The total time a vehicle is connected to the charger.

• Includes: Both the active charging period and any idle time after charging has finished.

Charging Duration

• Definition: The time during which energy is actively delivered to the vehicle’s battery.

• Excludes: Any idle plug-in time once charging is complete.

Why the Difference Matters

• Idle plug-ins reduce charger availability for other drivers.

• Charging duration provides a more accurate picture of actual energy delivery.

• Session duration helps track how long a stall is occupied, which matters for utilization and turnover.

Practical Example

• A car plugs in at 8:00 AM.

• Charging completes by 9:00 AM, but the vehicle stays plugged in until 10:00 AM.

Session Duration: 2 hours
Charging Duration: 1 hour

Best Practices

• Enable idle time alerts to encourage drivers to move vehicles once charging is complete.

• Track both metrics to:

  • Optimize fleet scheduling

  • Improve charger turnover

  • Maximize site utilization

Summary

• Session Duration = total time connected.

• Charging Duration = active charging time only.

• Monitoring both ensures fair access, better utilization, and smarter scheduling.