Fleet depot EV charging design: meet dispatch windows within available power

A depot charging plan succeeds when the required vehicles leave with enough energy, including on a difficult operating day. Daily kWh is the starting point; a time-based schedule reveals whether chargers, supply and parking operations can deliver it. A large connected charger capacity cannot recover hours when vehicles are still on the road.

This guide focuses on dispatch scheduling and resilience for depot managers. For a broader introduction covering employee cars and factory electrical readiness, use the existing factory fleet and employee charging guide. The example below is a planning exercise, not a design or a vehicle performance claim.

Create a vehicle-by-vehicle energy worksheet

Worked overnight schedule: twelve delivery vans

Assume 12 compatible vans each require 30 kWh added to the battery: 360 kWh per night. Assume 90% overall efficiency from the EV supply meter to the battery, so input energy is 400 kWh. There are eight usable hours, 22:00–06:00. The energy-average input is 400 ÷ 8 = 50 kW, but that alone does not prove the schedule works.

Assume four charging outlets can each deliver 15 kW DC when all four operate together, with no shared-cabinet restriction beyond that total. Each van requires two hours at a constant 15 kW delivered power. Three consecutive groups of four therefore take six hours. At 90% efficiency, the four active outlets need about 66.7 kW input. The illustrative site's verified EV allocation is 70 kW throughout the period. The schedule fits arithmetically, leaving two hours for delays; actual charging curves, auxiliaries and changeovers must then be checked.

If the outlets share one cabinet, or a single controller failure disables several chargers, the outage scenario changes. Record common failure points rather than assuming every gun is an independent spare.

Give load management a measurable job

Specify the maximum EV input at the site boundary, the priority rule for early departures, minimum useful allocations and the response when communications or metering fail. Ask the supplier to demonstrate that the limit is respected while the building load changes. Remote scheduling in a dashboard is not proof of dependable local power control.

Document which sessions may be deferred and how dispatch staff override priorities. Log missed energy targets and their causes: late vehicle, charger fault, utility outage, blocked bay or configuration. The distinction tells you whether to buy capacity, repair equipment or change the operating plan.

Reserve expansion routes without buying idle capacity blindly

Phase one can reserve space for an additional panel, cable routes, foundations or a future transformer while limiting initial equipment to the supported schedule. Re-run the model when vehicle types, routes or shifts change. Solar may offset daytime input, but overnight dispatch cannot depend on sunshine without a separately designed storage or energy arrangement. See the solar carport guide.

Check model-specific shared-output behaviour with the OEM; Exicom's compatible-charger power sharing illustrates why architecture matters. National charging guidance also treats e-bus depots separately; bus or heavy-truck procurement must be assessed against the relevant EVCI guideline provisions and vehicle requirements, not extrapolated from this van example.

Discuss a fleet or CPO rollout Share the site location and your requirement with Secured Engineers. Electrical infrastructure, charger supply, software and ongoing support responsibilities are agreed in the project scope.

Continue planning your installation

• Check charging power against vehicle limits
• Define acceptance and availability evidence

Sources checked 7 November 2026. Confirm the applicable order, equipment revision and site conditions before procurement.