Range planning for electric fleets: make energy demand and reserves traceable

Range planning for an electric fleet means matching the vehicle energy available to the energy required for a specific assignment. You need a current starting condition, suitable consumption assumptions, a justified reserve and reliable charging opportunities. A displayed range in kilometres alone does not fully describe these operating conditions.

Good planning makes uncertainty visible. It shows which values have been measured, which assumptions are being used and when another check is necessary. Dispatch can then respond to changing assignments without relying on a number presented without explanation.

Describe the assignment as an energy requirement

Start with the planned distance, including necessary additional trips. Also record payload, time windows and known special conditions. A schedule with several short trips may create different requirements from one continuous journey of the same distance.

The government guidance on planning EV journeys identifies terrain, temperatures and speed among the factors affecting range. Use these factors to structure your own assumptions. Do not turn them into blanket deductions for every vehicle.

Also define which trips must be covered. A known additional assignment can be included directly. Tasks that cannot be planned precisely need an explicitly justified reserve. Record who decides its size and when it will be reviewed.

Use consumption values with a suitable reference

Assign consumption to the relevant vehicle group and an appropriate operating profile. To calculate the battery energy required, it must be clear which measured quantity is being used. Electricity drawn for charging may include additional losses and therefore has a different measurement reference from a vehicle-side consumption figure.

Document the timeframe and source of the planning value. If you do not yet have your own data, mark the assumption as provisional and plan a review during operation. One favourable working day is not a reliable basis for every subsequent assignment.

Planning uses this simple relationship: distance in kilometres × assumed energy demand per 100 kilometres ÷ 100. The result remains an estimate subject to the limits of the inputs. New findings should be able to change the planning value in a traceable way.

Determine the energy available with a clear reserve

For a simplified calculation, you can multiply the assumed usable battery energy by the current SOC fraction. Both inputs must suit the specific vehicle. A historical capacity figure and an old state-of-charge value do not provide confirmed current energy reserves.

Subtract the defined operational reserve separately. This keeps it clear which portion is intended to be available for the planned assignment. The reserve is a planning decision, not a universal percentage. The vehicle's technical limits must also be considered.

Check the data status immediately before a relevant assignment. The article on SOC monitoring in the fleet describes how missing or outdated reports enter the workflow. The energy calculation depends on a suitable data foundation.

Worked example: an additional appointment changes the plan

Illustrative planning example, not a range guarantee: A vehicle is assumed to have 60 kWh of usable battery energy. At a current SOC of 70 percent, the simplified calculation gives 42 kWh. An illustrative operational reserve of 9 kWh leaves 33 kWh for the planned assignment.

The original 140 kilometres require a calculated 28 kWh at an assumed 20 kWh per 100 kilometres. The plan therefore has 5 kWh of headroom above the defined reserve. All figures serve only to explain the calculation.

A new appointment increases the distance to 180 kilometres. Calculated demand rises to 36 kWh, exceeding the 33 kWh available for the assignment. Before release, dispatch therefore checks an additional charging opportunity or a different vehicle assignment. The software should record the changed input and decision in a traceable way.

Add charging opportunities and a point for reassessment

If the assignment requires charging en route, access, the time window and the required energy amount must be plausible. Nominal charging power alone does not say how much energy will actually be taken on within the available time. Also plan a suitable alternative if the intended opportunity is unavailable.

Define a point at which the plan is reviewed again: for example, an additional appointment, a changed return time or an unusual consumption report. The person on the road needs a clear contact route and an understandable rule for what to do.

A planning sheet with the following information is sufficient to start:

1. Vehicle and current data status.

2. Distance including known additional trips.

3. Consumption assumption with its source and operating context.

4. Assumed usable energy and reserve.

5. Required charging opportunity with a time window.

6. Trigger for reassessment and responsible role.

Route planning for electric vehicles connects this energy check with appointments and operational workflows. At StromNow for fleets, you can discuss relevant questions about charging organisation. A specific range-planning or dispatch function needs to be checked for your environment.