> ## Documentation Index
> Fetch the complete documentation index at: https://docs.spirii.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Prioritised charging
> Keep the vehicles that can't wait at the front of the queue when power is short.
Prioritised charging gives a chosen vehicle the maximum power available at its connector whenever the site's power is being limited, ahead of everything else charging there.
## Overview
On a site where the fuse can't supply every charger at once, power is shared. That is the point of [DLM](/capabilities/energy-management/dynamic-load-management) — but an even share is the wrong answer for an ambulance, a police car, or the one van that has to be out at 05:00 whatever else happens.
Prioritised charging is the exception mechanism. Priority travels with the [charge key](/components/access/charge-keys), not with the vehicle or the connector: mark a key as prioritised, and any session authorised with it is prioritised at any location where you've allowed prioritisation.
Prioritised charging only does something when a power-limiting capability is active on the location. With no limit in place, every connector already delivers full power, so there is nothing to prioritise and priority keys are simply ignored.
## How it works
Two settings have to line up: the location has to accept prioritised sessions, and the charge key has to be marked as prioritised. When a session authorised with that key starts on that location, it is allocated the maximum power it can draw, and the remaining capacity is shared among the other vehicles under the normal distribution rules.
```mermaid theme={null}
flowchart TD
A("Session authorised with a prioritised charge key") --> B("Location accepts prioritised sessions?")
B -->|"yes, and a power limit is active"| C("Maximum available power to this connector")
B -->|"no, or no limit active"| D("Normal distribution")
C --> E("Remaining capacity shared among the other sessions")
```
When two prioritised vehicles charge at the same time, they split the available power evenly, each up to the maximum it can draw. Everything else on the circuit shares what is left, which on a tight circuit is very little. Priority is a blunt instrument by design, so mark keys sparingly — a fleet where half the keys are prioritised has no priority at all.
### What it does to the other capabilities
* **With DLM**, the prioritised session is served first from the circuit's capacity, then the rest is distributed.
* **With [scheduled charging](/capabilities/energy-management/scheduled-charging)**, a prioritised session ignores the schedule and charges immediately rather than waiting for the next selected interval.
* **With [grid balancing](/capabilities/energy-management/grid-balancing)**, priority does not win. Grid balancing sits above prioritised charging in the order things resolve, so a frequency activation still trims power on an enrolled charger.
### A worked example
A municipal depot runs eleven vans and two rapid-response vehicles on a circuit that can't supply them all at full power. The two response vehicles carry prioritised keys; the vans don't. On a normal night all thirteen share the circuit. When a response vehicle plugs in at 02:00, it takes the maximum its connector can deliver and the vans absorb the reduction between them. Nobody reconfigures anything, and the operator doesn't have to decide in the moment who matters.
## Options and configuration
| Setting | Where | Effect |
| -------------------- | -------------------------- | --------------------------------------------------------------------------------------------------------- |
| Allow prioritisation | The location, in Connect | Prioritised keys have an effect here. Off by default, and with it off the setting on the key does nothing |
| Prioritised | The charge key, in Connect | Every session authorised with this key is prioritised, at any location that allows it |
Both lists can be filtered on the setting, so you can see at a glance which locations accept prioritisation and which keys carry it. Completed sessions can be filtered by whether they were prioritised, which is how you check after the fact that priority went where you intended.
## When to use it
* **Emergency and response fleets.** The original case: the vehicle has to leave with as much charge as it can get, and a fair share isn't good enough.
* **A mixed depot with a few critical vehicles.** Refrigerated transport, on-call service vans, the vehicle covering the early shift.
* **A premium tier at a shared site.** Priority keys as a paid service for tenants or members who want the fastest charge available.
## Set up
Both settings are yours to make in Connect; there is nothing to enable on Spirii's side.
Prioritised charging has no effect on a location where nothing is limiting power. If the site has neither DLM nor a schedule, start there.
Edit the location and switch prioritisation on.
Edit each key that should carry priority.
## Dependencies and limitations
* **A power limit has to be active.** Without DLM or a schedule on the location, the platform has no allocation to bias and priority keys behave like any other.
* **Priority belongs to the key, not the vehicle.** Anyone charging with that key is prioritised, on any location that accepts it.
* **Spirii network only.** Priority doesn't travel over roaming — a prioritised key charging on another operator's network is treated as an ordinary session.
* **Grid balancing still applies.** An enrolled charger can be trimmed during an activation regardless of who is plugged into it.
* **The same charger model validation applies** as for the rest of energy management, per model and per firmware version.
## Related
Where priority is set, and how keys are issued to drivers.
The limit that makes priority meaningful in the first place.
A prioritised session charges immediately instead of waiting for its window.
Where a completed session records whether it was prioritised.