Scheduling electric-fleet charging when two vans need one charger

Two electric delivery vans return to the depot at 6:00 p.m. Only one charger is available. Van A leaves for a short route at 5:30 a.m.; Van B leaves at 7:30 a.m. for a longer route. A lower battery percentage on one dashboard does not, by itself, show which van needs the charger first. Scheduling electric-fleet charging means finding the charging order that makes both next assignments feasible, using each departure time, route energy need, vehicle condition and actual charger availability.

This is a fleet-dispatch decision for a scarce charger. It does not describe a charging-operations career or interpret an employment offer's charging duties. The owner must translate two next-day assignments into minimum readiness targets, estimate each van's charge time with a margin, and decide when to swap the connector. If both cannot be ready with the available equipment, the dispatch plan needs an explicit change before the morning launch.

Start with each van's next assignment

The next assignment sets the required departure and likely energy demand. Record route ID, start time, expected distance, stops, load, terrain or operating conditions relevant to the fleet's own energy model, and the return or recharge opportunity. A route labeled "short" can still consume more energy than expected if the vehicle carries a heavier load or operates in conditions that reduce efficiency. Use actual route history and fleet-approved estimates rather than a generic miles-per-percent rule.

Confirm which vehicle is assigned to which route. If the vans have different usable battery capacity, charging limits, cargo configuration or maintenance status, their assignments may not be interchangeable. A plan that assumes any van can cover either route may fail when one carries equipment needed only on the longer run. Check the departure commitment too: a van should be ready before drivers begin loading or vehicle checks, not merely reach its target at the exact gate departure minute.

For the worked example, Van A's short route starts at 5:30 and requires a modest energy addition; Van B's longer route starts at 7:30 and needs a larger addition. The scheduler has one overnight charging position and a safe, authorized way to swap vans. These conditions matter more than the visible battery percentages alone. A vehicle with a higher percentage can have a larger absolute energy gap for its assigned trip.

Keep non-charging readiness separate. A van under maintenance, with a tire problem or missing route equipment, is not dispatch-ready even if fully charged. The charging plan should not hide those issues. Scheduling electric-fleet charging addresses the energy constraint while the fleet's normal release checks address the rest of the vehicle.

Read state of charge with the vehicle context

State of charge describes battery level as a percentage of a vehicle's usable battery capacity. Record the reading and time when each van returns, along with any vehicle warnings or charging limits. A 35% reading on one van is not automatically less usable route energy than 45% on another if their batteries, health or energy consumption differ. Translate the display into the fleet's approved range or energy model for that specific vehicle.

Do not treat displayed range as a promise. It can respond to recent driving conditions and may not reflect tomorrow's load or weather. Compare the estimate with actual energy use on similar routes and with the reserve policy the fleet uses. If the vehicle has a battery or charging fault, route it to the responsible maintenance process instead of building a schedule around a normal charging rate it may not achieve.

The U.S. Alternative Fuels Data Center notes that charging time varies with battery depletion, battery capacity, vehicle charging capability and charging equipment, and that power can vary by vehicle and state of charge. That is why a simple division of needed energy by the charger's advertised maximum may be optimistic. Use actual charging-session data for these vans and this charger when available. State the assumed rate and the uncertainty rather than turning it into a guaranteed finish time.

In the example, suppose Van A returns at 42% and Van B at 28%. Van A's earlier departure may still make it first, provided its needed addition can be completed early and Van B then has enough charger time. Conversely, if Van B's long route needs far more energy and cannot fit after A, it may need the first block. The comparison must be about time to readiness, not a ranking of percentages.

Estimate route energy and reserve for both vehicles

Route energy is the energy required for the assigned work under the fleet's planning assumptions, including an approved reserve. Use recent actual data for the route or a validated route model. Record whether the route includes a planned charging stop, a depot return before the end of shift, or no practical recovery point. A van that can recharge midday has a different overnight requirement from one that must finish a long route before reaching any charger.

Calculate each minimum departure target in the unit used by the fleet: energy, state of charge, or verified route range. Include the reserve the operation requires; do not invent a universal percentage. Then compare the target with the current vehicle state to find the energy gap. If the target exceeds the vehicle's usable capacity, charging order cannot fix the assignment. The route, load or vehicle choice must change.

For illustration, assume the fleet's own route model says A needs to add about 18 kWh to reach its departure target and B needs about 42 kWh. These numbers describe the hypothetical schedule only. Suppose recent sessions at the available charger suggest A needs roughly three hours and B roughly seven, after allowing for the observed charging behavior. With more than thirteen hours between return and B's departure, a sequential plan may be feasible. The exact schedule still depends on when vehicles can be moved and how much buffer the fleet requires.

Check the target after any route change. An added delivery area or a substitution from a van with a different battery changes the needed charge. Avoid copying yesterday's target into a new assignment without rechecking the energy gap. The charging order is a plan for tomorrow's actual work, not a standing preference for one vehicle number.

Map the charger dwell available to each van

Charger dwell is the time a vehicle can occupy the charging position before it must be moved or released for its route. Record the charger type, connector compatibility, power actually available at the depot, start time, any site power limits, and who can perform an overnight swap. The Alternative Fuels Data Center discusses fleet charging schedules and staggering charging events. That capability depends on the equipment and depot setup; a shared physical connector still needs a workable handoff between vehicles.

Work backward from each readiness deadline. Van A's 5:30 departure might require charging complete by 4:45 to allow a check and loading. Van B's 7:30 departure might require completion by 6:45. With the illustrative three-hour and seven-hour charging needs, charging A from 6:30 to 9:30 p.m. and B from 9:45 p.m. to 4:45 a.m. would leave both ready under the assumed rates. The fifteen-minute connector change is an assumption that must match depot practice and available staff.

Test the reverse order too. Charging B from 6:30 p.m. to 1:30 a.m. and A from 1:45 to 4:45 a.m. could also fit, but it leaves A with almost no charging delay margin before its readiness deadline. The first sequence protects the earlier departure and still gives B time before 6:45. The decision is therefore based on feasible slack, not on the fact that B's battery reads lower.

Check whether an overnight swap is actually possible. If the depot has no authorized staff or automated switching arrangement at 9:30 p.m., the proposed A-then-B sequence exists only on paper. The operator might need to start B first, adjust assignments, arrange an earlier authorized swap, or use another approved charging option. Do not leave a plan dependent on someone noticing a phone alarm after the depot closes.

Protect a departure buffer against charging uncertainty

A departure buffer allows for charging-rate variation, a late return, a short equipment interruption and routine release work. Set it using fleet experience rather than a universal number. If one vehicle reaches its target only at the exact departure time under ideal charger output, the schedule is fragile. The U.S. Alternative Fuels Data Center's explanation of variable charging times supports treating estimated finish as a range, not a fixed appointment.

Look at the latest safe start time for each charging block. If A needs three hours and must be ready by 4:45, it must start before 1:45 a.m. with no margin; a planned start much earlier protects the launch. If B needs seven hours and must be ready by 6:45, a start after 11:45 p.m. would leave no margin under the illustration. The chosen swap at 9:45 p.m. gives B time to absorb some variation. Recheck the calculation with the actual charger and vehicle data.

Consider another possibility: Van B returns at 10:00 p.m. instead of 6:00. It misses the planned 9:45 swap, so its charging block starts later and its buffer shrinks. The dispatch owner should rerun the latest-finish check before keeping the A-first plan. A delayed return can turn a feasible two-van schedule into a one-van constraint.

State the escalation point. If a charging session underperforms by a specified time or the vehicle reports a fault, the named owner reassesses the morning assignments while alternatives are still possible. Waiting until the driver arrives at 5:00 a.m. leaves little room to switch vehicles, shorten a route or arrange another authorized charger.

Assign the charger and verify the actual sessions

Write the plan in a form the depot can execute: A on the charger from the confirmed start until its target, then B; identify the person or system responsible for the swap, the readiness targets and the morning check. Make sure both vans and the charger are compatible and physically accessible in that order. A blocked parking position can prevent the swap even when the electrical schedule is sound.

Record actual session starts, stops, energy added and final state of charge from reliable vehicle or charger data. The charging system may show a connector attached while no power flows because of a fault, schedule setting or interrupted session. A green indicator is not enough if the next assignment needs a known energy target. Check the vehicle state before dispatch and compare it with the fleet's route requirement.

If B is short of target at 5:00 a.m. but A is ready, the owner still has time to decide whether B can continue charging until 6:45, whether its route should be reassigned, or whether a permitted alternative charging stop is available. Do not quietly dispatch B below the approved route target. The decision should be recorded with the revised route or vehicle plan and communicated to the driver.

After the vans depart, compare estimates with observed results. If A consistently finishes earlier than planned, the schedule may gain slack. If B regularly needs longer than seven hours, the fleet should adjust its planning model or charging capacity. Scheduling electric-fleet charging works when the morning vehicles are actually ready, not when the spreadsheet shows a theoretical overnight fit.

Handle an infeasible one-charger night

Suppose the charger becomes available only at midnight and the two vans still need three and seven hours. Ten hours of charging cannot fit before both departure deadlines, even if the charger supplies its expected rate without interruption. The owner must change a constraint: use another authorized charger, swap route assignments, reduce a route's energy demand with a verified plan, delay a departure through the proper process, or substitute a ready vehicle. A paper schedule with overlapping blocks does not create charger capacity.

Choose an alternative by preserving the most time-sensitive valid handoff and documenting its effect. A route reduction must reflect actual stops and customer commitments, not a lower reserve invented to make the numbers fit. An en-route charge is useful only if a compatible station, dwell period and route timing are credible. A different van must meet the route's cargo and maintenance requirements as well as energy need.

If charger faults recur, investigate the equipment and the shared planning path. Test the repair with the affected session and a later normal charging night before relying on it. Preserve the missed-readiness record; a corrected dashboard does not undo a delayed departure. The fleet may need a second charging position or more schedule flexibility, but that investment decision requires actual utilization and route data beyond one difficult night.

Readers exploring adjacent logistics work can use the driver guide hub, and job seekers can review the Fort Wayne driver careers page. For the two vans, the charger goes first to the vehicle whose timing and energy gap need that block, with a verified swap and enough margin for the other van's departure.