What is depot charging?
Depot charging is the charging of electric fleet vehicles at a dedicated operating base, usually overnight or between shifts, while vehicles are parked during their scheduled dwell time. It is a common charging model for electric buses, delivery vans, trucks and service fleets that regularly return to a central location.
Unlike en-route charging, which takes place during a vehicle’s journey at charging locations along the vehicle’s route, depot charging is defined by control and predictability. The operator knows when each vehicle returns, how long it stays and when it must leave, so charging can be scheduled around the grid capacity available, the electricity price and the fleet’s own priorities.
How does depot charging work?
Five things have to line up for every vehicle to leave with enough charge:
- Grid connection. The depot needs enough electrical capacity for its fleet, and a new or upgraded connection is often the longest lead-time item. TwentyForty, a UK freight infrastructure body, reported in July 2026 that an 11 kV depot connection takes 18 to 36 months to build even in a market that works. Actual timelines depend on local network capacity and the scope of the project.
- Charger selection. Charger power depends on vehicle type, battery size, daily energy use and dwell time. AC charging at 7 to 22 kW suits light commercial vehicles with long overnight stops; electric buses and heavy-duty trucks usually need higher-power DC charging. A 2021 National Renewable Energy Laboratory (NREL) study found that the short-haul fleets it examined met their overnight needs at 100 kW per vehicle or less.
- Charging schedules. Each vehicle’s departure time, state of charge on return and required energy set its charging window.
- Managed charging. A charge point management system (CPMS) shares the available power across chargers by vehicle priority, departure time and site power limit, using dynamic load management to keep the combined demand under that limit; dynamic load management is one form of smart charging. In the same NREL study, about 80% of the 36 distribution substations examined could supply modeled loads for 100 heavy-duty trucks charging at up to 100 kW each without upgrades. Managed charging raised that share by about 10 percentage points. The findings reflect the fleets and networks studied.
- Integration and reporting. Charging software can take departure times and routes from telematics and fleet management systems, and report energy use and cost by vehicle, driver or charge point.
Depot charging vs. other fleet charging models
Most fleets run more than one model: the depot covers the regular routes, public charging covers the days a vehicle runs beyond them, and drivers who take a van home charge it there.
| Aspect | Depot charging | En-route and public charging | Driver home charging |
|---|---|---|---|
| Location | Dedicated fleet depot or operating base | Public or third-party charging sites | Employee’s home |
| Scheduling | Planned around fleet operations | Fleet plans stops, but access depends on site availability | Coordinated with the driver |
| Electricity costs | Site tariff; managed charging can shift load into cheaper periods on time-varying tariffs | Public charging tariffs | Domestic tariffs, often reimbursed |
| Typical power | AC 7–22 kW; DC commonly 50–150 kW for buses and trucks | DC 50–350 kW | AC 7–11 kW |
| Best suited for | Return-to-base fleets | Long routes and mid-shift charging | Vehicles kept at home overnight |
Electric bus operators often pair overnight depot charging with opportunity charging: short, high-power top-ups at terminals or along the route.
Benefits and limitations of depot charging
The advantage is control over charging schedules and energy costs. Fleet operators can shift charging into lower-cost electricity periods, rely less on public charging networks and see energy use vehicle by vehicle. Where the tariff has a demand or capacity charge, the highest peak in the billing period sets part of the bill. Lowering that peak with managed charging then cuts costs even when the energy price is flat.
The limitations are on the infrastructure side. Grid connection capacity, charger installation, civil works, parking layout and, on a leased site, the landlord’s consent all affect cost and timing. The economics then rest on the site tariff, how hard the vehicles are worked and a schedule that gets every vehicle to its departure charge without creating a new peak.
What regulation is driving depot charging?
EU regulation puts manufacturers on a fixed timeline for electric heavy-duty vehicles. Regulation (EU) 2024/1610 requires manufacturers to cut the average CO2 emissions of the new trucks and buses they sell by 45% from 2030, 65% from 2035 and 90% from 2040, for the vehicle groups it covers. It also requires 90% of new urban buses to be zero-emission from 2030 and 100% from 2035. Fleet operators therefore need to plan the grid connection well ahead of vehicle replacement, since the connection can take several years.
How AMPECO supports depot charging
AMPECO’s EV charging management platform for fleet operators supports depot charging with dynamic load management, which shares power across the depot’s charge points to keep the site within its power limit. Charging priorities put operational vehicles ahead of lower-priority users such as employee cars.
Its APIs connect the platform to vehicle telematics, route management and other fleet software, and usage and cost reporting runs by charge point, vehicle or driver.
For vehicles that charge away from the depot, the same platform covers en-route charging through EV roaming and employee home charging.
Frequently asked questions
Do depot chargers need to be DC?
Not always. AC charging suits electric vans, cars and other light commercial vehicles that sit overnight and use a modest amount of energy each day. Electric buses, heavy-duty trucks and fleets with short charging windows usually need DC charging because they must take on more energy in less time. Overnight fleets often plan about one charge point per vehicle so everything plugs in on return, while a DC charger with shorter sessions can serve several vehicles in turn.
How much grid capacity does a depot need?
Grid capacity depends on the number of vehicles, their daily energy needs, their charging windows and the site’s other loads. Dividing the fleet’s daily energy by the hours it is parked gives a starting estimate, but the connection must also cover overlapping schedules, charging losses and the resulting peak. Managed charging spreads power across vehicles instead of running every charger at full output at once, which lowers that peak and can defer an upgrade. For example, 20 vans that each need 40 kWh during a 10-hour overnight window need an average of 80 kW, before charging losses, other site loads and overlapping schedules.
Related terms
- Dynamic Load Management (DLM)
- Smart Charging
- Load Shifting
- Peak Shaving
- Workplace EV Charging
- En-route EV Charging
- Vehicle-to-Grid (V2G)
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