Fleet Depot Charging Design and Consulting

Start from the duty cycle

Daily distance, load, terrain, ambient conditions and auxiliary use determine energy consumed. That number, not the battery, sets what has to be replaced overnight.

Where telematics data exists, use it. Where it does not, the first step is collecting it, because designing a depot against an assumed duty cycle is designing against a guess.

The dwell window is the real constraint

Energy divided by available hours gives required power. A fleet that returns at 18:00 and departs at 06:00 has twelve hours, which usually means modest AC charging is sufficient. A fleet with a two-hour turnaround has a completely different problem.

Shortening the assumed dwell window is the single fastest way to inflate a depot's cost, and it happens whenever operations and engineering do not talk.

Sequencing beats simultaneity

Not every vehicle needs to charge at once, and designing as though they do multiplies the supply requirement. Sequenced charging across the dwell window, prioritised by departure time, typically supports the same fleet on a fraction of the connection.

Bay count and vehicle movement

Charge points can be fewer than vehicles if there is a plan for moving them, and shunting vehicles overnight has a labour cost that has to be compared against the capital saved. Where nobody is on site overnight, one point per vehicle becomes the practical requirement.

Contingency

The design must answer what happens when a charge point fails, when a vehicle does not charge overnight, and when the depot loses supply. A fleet that cannot start its shift is a business interruption rather than a maintenance ticket.

Growth

Fleets electrify in tranches. Infrastructure sized for the first tranche, with no plan for the second, is the most expensive way to arrive at a fully electric depot. Establish the end state early even if it is built in stages.

Depots are the easiest place to schedule and the easiest to oversize

A depot is the most favourable charging environment there is. The vehicles are known, the dwell time is known, the departure time is known, and no driver is waiting at the charger. Almost every constraint that makes public charging hard is absent.

Which is why depots are so often oversized. Sizing against simultaneous full-rate charging produces a supply requirement, a civil bill and a capital number that the operation never needed. Sizing against the departure schedule produces a different answer, usually a much cheaper one, and the vehicles still leave full.

The general principle we work from is that availability matters more than power. A point that is free when the vehicle arrives beats a faster one that is occupied. In a depot that translates directly into more points at lower power, less supply reinforcement and fewer vehicles waiting.

How we work with you on this

Depot work is done with your operations team, not just your engineering team. The constraint that decides the design is the departure schedule, and that lives with the people who run the fleet.

We will frequently recommend less charging capacity than was budgeted. A depot sized against the departure schedule rather than against simultaneous full-rate charging usually needs considerably less, and telling you that reduces what you buy from us.

What we actually provide

To be clear about scope: we provide the technical charging solution. We do not design the depot itself, and a depot layout consultant is a different engagement.

1. 1

   Plug in and charge, with no QR

   A depot driver should not be scanning anything at the end of a shift. Vehicles are recognised on connection, by RFID or by our own recognition technology, and the session starts, which removes the step most likely to be skipped. ISO 15118 Plug and Charge is not part of this today.

2. 2

   Load management across many vehicles

   A depot charges everything at once or it charges nothing sensibly. Allocation against the connection, and against departure times where they are known, is what makes the supply work.

3. 3

   Analytics

   Energy per vehicle, per route, per shift. Cost attribution that a fleet manager can actually use, rather than a site total.

4. 4

   Spares and stock

   Uptime in a depot is not negotiable, because a charger down is a vehicle that does not leave. Holding spares and having control over the hardware is what makes a response measured in hours rather than weeks.

Why hardware control matters here more

In public charging a unit down costs a session. In a depot it costs a vehicle out of service, which is a different order of problem.

That is the argument for owning the hardware relationship rather than renting it. Spares on site, a supplier who can diagnose remotely, and firmware you can update without waiting in a supplier's queue. A depot running on equipment that cannot be serviced quickly is a fleet with a single point of failure in its car park.