Read the charging curve before the peak power

A peak charging figure is easy to compare and easy to misinterpret. It describes a point in a session rather than the session itself. A vehicle programme or fleet buyer needs to know how much useful energy can be added during the available stop, under conditions it is likely to encounter. Reading the charging curve turns a headline power figure into an operational question.

Use the relevant charge window

Define the arriving and departing charge conditions that matter for the journey. A comparison based on a different window may favour a vehicle without improving the fleet's actual stop. The required departure condition should follow the remaining work and reserve policy, rather than a habit of filling every battery to the same target.

Then examine energy delivered and time across that window. Average power over the useful interval helps explain the practical result, but it still needs supporting conditions. Include the point at which energy delivery begins and whether the measurement excludes connection, authentication or other steps that consume time during a real visit.

Record why the curve changes

Battery condition, vehicle control and infrastructure capability can affect the session. The Alternative Fuels Data Center identifies state of charge, battery and charger characteristics among the factors governing charging time. This means a curve should arrive with a test description, not as an unexplained line on a presentation.

Record battery temperature, software configuration, charger output capability and any power sharing. If the vehicle was prepared specifically for the test, state how that preparation was achieved. This lets the buyer distinguish a reproducible operating routine from a favourable starting condition that the proposed route rarely provides.

Compare several useful sessions

Request results for the situations the vehicle will encounter. A first rapid stop after a prepared journey may answer a different question from a later stop during repeated motorway work. Where weather or site capability differs, test the relevant combination rather than assuming one published curve covers it.

Keep the same measurement definitions across vehicles. If one result starts when the connector is inserted and another starts after charging begins, separate those stages before comparing them. The aim is a like-for-like account of energy and time, not a contest between whichever reporting method produces the most attractive number.

Translate the graph into a stop plan

A dispatcher needs departure readiness, charger access and a workable fallback. Combine the charging evidence with site availability and the time required to enter, connect and leave. A fast energy-delivery interval may still be unsuitable if the vehicle cannot use the bay or depends on an unreliable access arrangement.

The final comparison should show what the curve means for the particular journey. It may support a shorter stop, a different departure target or a revised charging location. Peak power remains useful as a component of that explanation, but the purchasing decision should rest on the complete, evidenced session that the vehicle can deliver within its operating plan.