Sessions

Sessions list past and ongoing (active) charging sessions from the charging network.

Topics in this document:

Sessions Overview

To access this section in EV Charge, from the Menu, click Sessions. A paginated list of all sessions from a specific period is shown in a tabular format.

To produce charging sessions, please refer to Charging Sessions Integration, to find the guidelines.

To generate the sessions list in a spreadsheet, click CSV. To print, click Print, and to copy, click Copy.

The session list will be empty if no active charging session has been made on the charging network.

For all charging sessions, it shows:

  • the charger and connector used to charge the vehicle
  • the date-time the session started and ended
  • session duration scopes (charge time, park time)
  • the customer ID
  • the total energy (kWh) consumption from the session
  • the monetary amount

An ongoing session (a session in progress) will be shown with a Status flag as In progress. Also, the consumption and amount of the active session will be updated in EV Charge as any live update occurs.

Session Status

Represents the latest status of the session.

Session statusDescription
ReadySession was requested to start by the driver. Central system is waiting for the charger to start the charging process.
RefusedSession refused to start. Reason could be insufficient driver’s resources, configuration issue or other failure.
ReservedSession is reserved for the driver. Only the driver which reserved the charger can proceed to charging until reservation expires.

Reserved session can transition to an actual charging or expires and closes otherwise.
In progressSession is charging.
Limit reachedIndicates that session has reached one of the configured limits:

- Monetary limit

- Energy limit

- Charge time limit

- Not able to authorize additional driver’s resources
ClosedFinal stage when session is completed and driver’s resources are spent.

Final stage of session depends on the session settings configuration, whether it ends by the charging end or by parking end.

See “Session settings”.
Rating failedIndicates that session is over regarding the session settings, but the driver was not monetarily rated.

Retry operation can be used on domand or by an automated job execution.
Billing failedIndicates that session is over regarding the session settings, but the pay-now driver was not billed.

Retry operation can be used either on demand or by an automated job execution.

Session Actions on the Dashboard

Session actionDescription
Force closeWhile session is ready/in-progress, system operator may demand to forcefully close the session by using the EV Charge dashboard, by clicking the close button on the right side.

This operation requests the session to stop on the charging infrastructure, but if the infrastructure is not responding for any reason, session is forcefully closed.

Driver is rated, session closes. See more details of this status in Requesting the Session to Stop.
Retry ratingWhile session is in rating failed status, retry rating button is available for use.

When triggered, session rating is retried. See more details of this status and possible actions in Retry Session Rating.
Retry billingWhile session is in billing failed status, retry billing button is available for use.

When triggered, session billing is retried. See more details of this status in Session Retry Billing.

Idle Session Control

The pre-configured recurring background job checks for idle ready/ongoing sessions and also closes any expired reservations. The session is idle, regarding the Site/Operator settings. See Idle Session Settings.

Session Rating Settings

These are settings which apply for the rating of session, considering different metric types.

Rating settings are determined on the following levels:

  • Site (lowest priority)
  • Operator
  • Charger (highest priority)

Settings are overridable, meaning the settings of the highest priority level are used.

Below are the rating settings available:

Table 1: Description of session rating settings

Setting nameUnit/valueDescription
Energy stepkWhEnergy step for rating authorization control (kWh).
Charge time stepsecondsCharge time step for rating authorization control (seconds).
Park time stepsecondsPark time step for rating authorization control (seconds).
Park time thresholdsecondsDefines seconds threshold, as point in park time duration at which parking becomes ratable.

Difference between the total park time and threshold (park_time minus park_time_threshold) is ratable quantity. Rating authorizations start executing once threshold breaches.
Reservationtrue / falseIndicating whether the charging reservations are being authorized by rating.
TerminationApplicable values of:
- Session end
- Park time end
Indicating which action stops the charging session on the server side.
Monetary limitSite currencyMax. monetary amount allowed for a session.

Zero represents no limit.

When limit is breached, charging session is requested to stop.
Energy limitkWhMax. energy amount to be consumed for a session.

Zero represents no limit.

When limit is breached, charging session is requested to stop.
Charge time limitsecondsMax. duration allowed for a session to charge.

Zero represents no limit.

When limit is breached, charging session is requested to stop.
Payment auth policyApplicable values:
- None
- Initial auth only
- Auth control
Payment authorization policy which applies for pay-now customers and defines how charging session is controlled by payment provider’s authorizations.
Payment auth amountSite currencyAmount used for session’s payment authorizations.
Charge time priceSite currencyPrice per hour of charging time.

Used in scope of simple pricing.
Park time priceSite currencyPrice per hour of parking time.

Used in scope of simple pricing.
Energy consumed priceSite currencyPrice per kWh of energy consumed.

Used in scope of simple pricing.
Home roaming energy priceSite currencyHome roaming energy price (per kWh).

Applies for monetary amount calculation, if session is in roaming on CPO of Tridens EV Charge, but customer/driver is of third-party roaming eMSP.
Home roaming charge time priceSite currencyHome roaming charge time price (per hour).

Applies for monetary amount calculation, if session is in roaming on CPO of Tridens EV Charge, but customer/driver is of third-party roaming eMSP.
Home roaming park time priceSite currencyHome roaming park time price (per hour).

Applies for monetary amount calculation, if session is in roaming on CPO of Tridens EV Charge, but customer/driver is of third-party roaming eMSP.
Home roaming reservation time priceSite currencyHome roaming reservation time price (per hour).

Applies for monetary amount calculation, if session is in roaming on CPO of Tridens EV Charge, but customer/driver is of third-party roaming eMSP.
Home roaming reservation fixed priceSite currencyHome roaming fixed reservation price (flat fee).

Applies for monetary amount calculation, if session is in roaming on CPO of Tridens EV Charge, but customer/driver is of third-party roaming eMSP.
Start Restriction - Connector Occupiedtrue / falseIndicates whether the connector/socket is required to be occupied (EV connected) for the charging session start request to proceed.

Requesting the Session to Start

Sessions can be initiated in the following ways:

  • Driver as mobile user requests to start the charging session on the selected connector. The central system verifies that customer for the sufficient monetary resources and in case of success, it forwards the request to the charging infrastructure and requests it to start the charging process, upon which the charging session is expected to start.

  • Driver swipes an RFID device, uses NFC, Plug & Charge or any other way to initiate the session authorization at the charger side. Charger uses the identification means and asks the central system to verify the customer, whether he/she has sufficient monetary resources to charge and in case of acceptance, the charging is expected to start.

  • Driver starts charging immediately on the charging station, without prior authorization. In this case, the session customer is not known and not charged.

When customer is detected, but is not successfully authorized for the charging session, the session is persisted as rejected. Otherwise no session is persisted.

Duration Scopes

While the charging session is in progress, the applicable charger’s connector status impacts how the session is being tracked by the Tridens EV Charge central system and thus how it appears to the drivers on mobile application.

Session duration is being separated into scopes of charge time, park time, reservation time and fault time. See table below to see which status applies for the specific duration scope.

Table 2: Duration scopes and applicable Connector statuses

Duration ScopeApplicable Connector Statuses
Charge timeCharging
Park timePreparing,
Occupied,
Suspended EV,
Suspended EVSE,
Finishing,
Available.
Fault timeFaulted,
Unavailable
Reservation timeReserved

Requesting the Session to Stop

While session is ready/in-progress, system operator may demand to forcefully close the session using the Tridens EV Charge dashboard, by clicking the close button on the right side. This operation requests the charging session to stop on the charging infrastructure, but if the infrastructure is not responding for any reason, session is forcefully closed.

Driver is rated, and the session closes.

The table below shows how session stop requesting may reflect on the charging infrastructure.

Table 3: Charging infrastructure reflecting the session stop command

Stop Response TypeDescription
AcceptedCharging infrastructure accepted the stop request. It is expected that it will send the session stop event.
RejectedSession is not being closed on the charging infrastructure.

Force session close covers the following issues:

  • Remote stop request is accepted by the charge point, but no stop event confirmation comes from the charging infrastructure.

  • Remote stop requests are always rejected by the charging infrastructure.

  • Charging infrastructure is not responding due to lost connection to the central system, lost track of the session.

Termination Strategy

Once the stop session event comes from the charger, it depends on the Tridens EV Charge’s configuration of session termination strategy (see Session Rating Settings) how the event impacts the session.

If desired, the session can be completed at that point, or alternatively the session can continue to be tracked for the idle/park time, until the connector remains connected to the vehicle.

Park time end detection may be different based on the charger implementation by the manufacturer, as different actions may indicate when the charging session is over, as it can be by unplugging the connector, or until leaving the parking spot completely. So this can be configurable on the charger side.

Table 4: Session termination strategy

Strategy nameDescription
Charging endAt the session stop event from the charger, the central system stops tracking the session and applies the final session fees for the driver. Session gets closed.
Parking endAt session stop event from the charger, the central system keeps tracking the session in park time, until connector is released. At the time of connector’s final release, the central system stops tracking the session and applies the final session fees for the driver. Session gets closed.

Session Retry Rating

Session in rating-failed status indicates that the charging session is over, but the driver was not monetarily rated. Thus, retry rating operation can be used to charge the driver/customer of the charging session. The driver’s payment type, billing and payment may also apply afterwards.

Session’s rating-failed status may arise for the following reasons:

  • Invalid Monetization rating configuration, which causes that session can not be rated for the customer. This could be a configuration issue of rate plans, products, rating metrics or customer’s subscription-plan setup.

  • System maintenance work.

Session retry rating can be used in different modes to determine rating session identifier, used for Monetization charge event rating when session is in rating-failed status.

See the table below.

Table 5: Rating identifier modes of session retry rating

Rating Identifier ModeDescription
Use existingExisting session rating identifier is being used for Monetization rating. Default option.
Use existing, otherwise generate newExisting session rating identifier is being used for Monetization rating. If rating fails, new rating identifier is auto-generated by the system and rating automatically retries.
Assign newNew explicit session rating identifier is assigned in the request and used for Monetization rating.
Generate newNew rating identifier is auto-generated by the system and used for Monetization rating.

Session Retry Billing

Session in billing-failed status indicates that the session is over regarding the session settings, but the pay-now driver/customer was not billed. Thus, retry billing operation can be used to retry billing and payment of a driver for the charging session.

Session’s billing-failed status may arise for the following reasons:

  • Invalid Monetization rating and billing configuration, which causes that session can not be rated for the customer. This could be a configuration issue of rate plans, products, rating metrics, customer’s subscription-plan or billing profile setup.

  • System maintenance work.

Idle Session Settings

Session on the central system is considered as idle when not receiving event reports from the charging infrastructure after a certain configured time of Site or Operator. Operator’s settings have higher priority, if set.

When session is detected as idle, the central system closes/completes it, which means that such session is not being tracked anymore.

Setting nameDescription
Ready session expirationAllowed inactivity in seconds for a ready charging session.
When background job detects a ready session’s inactivity exceeding this time, it finalizes it (rating and closing).
Ongoing session expirationAllowed inactivity in seconds for an ongoing, in-progress charging session.
When background job detects an in-progress session’s inactivity exceeding this time, it finalizes the session (rating and closing).
Session closed verification timeAmount of seconds since the session stop request, after which session is verified to be closed. Used in scope of force stopping and idle sessions stopping.
Limitation: This settings only applies for the Site currently.

Table: Session expiration settings

Pre-configured idle sessions job operation is responsible for detecting idle sessions based on expiration settings of Site and Operator.

Job’s execution interval determines how often the central system checks for the idle sessions.

Consider these effects in scope of ready-session-expiration:

Consider these effects in scope of ongoing-session-expiration: