Menu

Let flexible sessions wait

Let flexible sessions wait for cheaper hours, so the cars that need to leave soon get the circuit's current first.

3 min readEdit this page
On this page

On a shared circuit, every car that wants more gets an equal share. To put some cars first, tell Flowion which sessions can wait: give a session a finish time and the energy it needs, and Flowion moves its charging into the cheapest hours before that time. While it waits, its share goes to the cars charging now.

A fleet van that is parked overnight and leaves at 07:00 can wait. A visitor who leaves in an hour cannot. Mark the van, and the visitor charges faster while the van fills up later at a lower price.

This needs prices for the location: a supply contract and a price zone, so Flowion knows what each hour costs. See Use day-ahead electricity prices.

Mark a session as flexible

Once a session is running, set when it must be done and how much energy it needs:

PUT/v1/transactions/$TRANSACTION/deadlinebash
curl -X PUT "$API/transactions/$TRANSACTION/deadline" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"chargeBy": "2026-10-02T05:00:00Z", "energyKwh": 40}'
200Response
{
  "chargeBy": "2026-10-02T05:00:00Z",
  "energyKwh": 40
}

  • chargeBy is when the session must be finished. It can be as far ahead as price forecasts reach; further is 422 invalidValue.

  • energyKwh is the session's total at the meter, including what it has already charged — not the battery's size and not what is still missing. More than 0 and at most 1000.

  • Both are needed. A chargeBy without energyKwh changes nothing about how the session is shared.

  • Setting it again replaces it. Leaving out energyKwh on a later call clears the goal.

It needs the session.deadline.manage permission.

What Flowion does with it

Flowion looks at the price of every 15 minutes between the car plugging in and chargeBy, and picks the cheapest ones that still deliver energyKwh in time. Outside those, the session is paused at 0 A or held lower, and the current it leaves is shared between the other cars on the circuit.

  • It finishes on time first. When the time left only just covers the energy, the session charges now, whatever the price.

  • It never flaps. A session does not switch between paused and charging more often than every 10 minutes, because some cars end a session when that happens.

  • A goal it cannot meet — too little time even at full power — means the session simply charges now, uncapped by price.

  • After the goal is met, it keeps charging only in hours as cheap as those it already used.

  • The circuit still comes first. A flexible session never gets more than its circuit can spare.

Flowion starts planning once the session has reported a couple of meter readings. If it has no prices for the location, the session charges like any other.

Check, change or clear it

GET/v1/transactions/$TRANSACTION/deadlinebash
curl "$API/transactions/$TRANSACTION/deadline" \
  -H "Authorization: Bearer $TOKEN"

204 means the session has none. To remove one:

DELETE/v1/transactions/$TRANSACTION/deadlinebash
curl -X DELETE "$API/transactions/$TRANSACTION/deadline" \
  -H "Authorization: Bearer $TOKEN"

See the plan

GET /projects/{projectId}/planned-schedule lists, for each session with a finish time, the periods ahead and the current each is allowed. In the allocation log, changes made for a flexible session carry the reason priceWindow (waiting for or charging in a cheaper hour) or deadline (charging now to finish in time).

Endpoints

Charging Priority · Energy

In the API reference