Fleet charging schedules are planned rules and time windows that control when, how fast, and in what priority fleet vehicles charge—so the right vehicles are ready by departure time while minimizing electricity cost, peak demand, and site overload risk. Scheduling can be manual (set times) or automated through a CPMS/EMS using load management, tariffs, and vehicle constraints.
What is a fleet charging schedule?
A fleet charging schedule is a set of parameters applied per site, charger group, or vehicle, typically including:
– Allowed charging windows (e.g., 18:00–06:00)
– Priority logic (which vehicles charge first)
– Power limits (site cap, per-charger cap, per-group cap)
– Target energy or state-of-charge (SoC) by a deadline
– Exceptions (urgent vehicles, late arrivals, preconditioning)
Why fleet charging schedules matter
– Ensure vehicle readiness (charge complete by shift start / dispatch time)
– Reduce energy cost using time-of-use tariffs or off-peak pricing
– Avoid demand peaks that trigger demand charges or trip site limits
– Prevent queueing and charger congestion during return-to-depot waves
– Protect infrastructure by keeping total load within transformer/switchboard limits
– Improve utilization by spreading sessions across the night/day
Common scheduling strategies (used in real depots)
Departure-time scheduling (deadline-based)
– Objective: every vehicle hits a target SoC by its planned departure time
– Best for: fixed routes, predictable shifts, buses, delivery vans
Off-peak / tariff-based scheduling
– Objective: shift charging into cheapest hours (or lowest carbon hours)
– Best for: sites with strong TOU price differences, high energy volumes
Power-cap / peak-avoidance scheduling
– Objective: keep site load below a hard cap (e.g., 120 kW total)
– Best for: limited grid capacity, expensive demand charges, constrained depots
Rotation / fairness scheduling
– Objective: cycle chargers between vehicles to avoid one vehicle hogging power
– Best for: many vehicles, few chargers, long dwell times
Priority-based scheduling
– Rules like: “low SoC first”, “earliest departure first”, “critical vehicles first”
– Best for: mixed fleet types, variable arrival times
Opportunity charging windows (daytime/top-up)
– Objective: short top-ups during loading breaks or between shifts
– Best for: multi-shift operations, high utilization fleets
Inputs you need to build a good schedule
– Vehicle arrival time and departure time (or shift plan)
– Required range / target SoC (or kWh needed)
– Charger power (AC kW), number of bays, connector types
– Site capacity limit (main breaker/transformer)
– Tariff structure (fixed vs TOU, demand charge rules)
– Operational constraints (loading, parking, key management)
– Optional: weather/preconditioning needs, battery health limits
Typical schedule “templates” you can deploy fast
Template A: Simple off-peak window
– Allow charging 22:00–06:00
– Site cap: X kW total
– Priority: earliest departure first
– Emergency override for vehicles below Y% SoC
Template B: Two-wave return depot
– Wave 1 (18:00–22:00): charge only vehicles departing before 05:00
– Wave 2 (22:00–06:00): charge all remaining
– Keep a strict site cap to avoid evening peak
Template C: Mixed fleet (cars + vans)
– Cars: slow overnight (low priority)
– Vans: deadline-based to hit dispatch SoC
– Reserve 1–2 chargers for late arrivals/urgent jobs
Best practices
– Schedule around fleet outcomes, not charger outcomes: “ready by departure” is the KPI
– Always set a site power cap and per-group limits
– Build an override workflow (urgent vehicle, missed plug-in, maintenance)
– Use monitoring + alerts: plugged-in not charging, charging stopped, breaker trips
– Review weekly: utilization, peak load, missed readiness events, queueing incidents
– Keep it simple first, then optimize: start with windows + caps, add priorities later
Common mistakes
– Charging everything immediately on return → creates evening peaks and overloads
– No “deadline logic” → vehicles with early departures get stuck waiting
– Ignoring operational reality (vehicles not plugged in, bay blocked, keys unavailable)
– No exception handling → schedule breaks the first time something changes
– Not limiting power at the site → demand charges wipe out savings
Related glossary terms
Fleet power management
Dynamic load management
Time-of-use tariffs
Demand charges
Depot charging
Charging readiness KPI
Active power throttling