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Electric Truck Charger Utilization Calculator

This calculator measures how intensively an electric truck charger is used during a selected reporting period. It compares total connected charging hours with the charger's available hours and also estimates energy-based utilization from delivered kilowatt-hours and rated power.

The two views help depot operators identify scheduling congestion, oversized equipment, or differences between time connected and time actively charging. Utilization alone does not show whether every truck departed on time, so it should be reviewed alongside queue time, charging completion, and route readiness.

Calculator inputs

sessions
hr/session
kWh
kW
days
%
Result
—
Connected-time utilization
Energy-based utilization—
Connected hours—
Available hours—
Average energy per session—

1. Count charging sessions
Use completed or connected sessions within one reporting period.

2. Measure connected duration
Enter the average time a truck occupies the charger, including taper and post-charge dwell.

3. Enter delivered energy
Use metered kWh for the same period.

4. Set charger rating
Enter the nominal maximum output of the charging port.

5. Define the reporting window
Enter days and reduce availability for downtime or planned closures.

6. Compare both utilization views
Use time utilization for bay occupancy and energy utilization for asset throughput.

Available hours = Reporting days × 24 × Availability percentage

Connected-time utilization = Sessions × Average connected time ÷ Available hours × 100

Energy-based utilization = Energy delivered ÷ (Rated power × Available hours) × 100

What the result means

Connected-time utilization shows the percentage of available charger hours occupied by trucks.

Energy-based utilization may be much lower when vehicles remain connected after power tapers or charging finishes.

Given: 90 sessions, 1.8 connected hours each, 35,000 kWh delivered, 350 kW rating, 30 days, and 96% availability.

Calculation: Available hours = 30 × 24 × 0.96 = 691.2 hours. Connected hours = 90 × 1.8 = 162 hours. Time utilization = 162 ÷ 691.2 × 100 = 23.44%. Energy utilization = 35,000 ÷ (350 × 691.2) × 100 = 14.47%.

Result: The charger is occupied about 23.4% of available time and used at 14.5% of its theoretical energy capacity.

Why are there two utilization percentages?

Time utilization measures occupancy, while energy utilization measures delivered energy relative to theoretical maximum output. They answer different operational questions.

Can connected-time utilization exceed 100%?

It can only do so if inputs are inconsistent, such as overlapping sessions assigned to one port or underreported available hours. Check whether the charger has multiple independently usable connectors.

Should downtime reduce available hours?

Yes. Enter an availability percentage that excludes maintenance, faults, and intentional closure periods.

Does high utilization always mean the charger is undersized?

No. High utilization can be efficient if schedules remain reliable, but it may leave little resilience for delays or extra routes.

How can dwell after charging be identified?

Compare connected-time utilization with energy-based utilization and session logs. A large gap can indicate tapering, completed vehicles remaining plugged in, or low-power operation.