Charging with Session Targets

Setting Session Targets

eDRV provides developers the ability to start sessions in a fire and forget mode. This means that eDRV's session intelligence takes care of the post session monitoring for you in specific use cases, allowing you to shape the session once at start time.

You are free to design sessions in any combination of the following targets:

• Energy (kWh)
• Time (Minutes)
• State Of Charge (Percentage)
• Money (Amount)

For e.g. you may choose to start delivering energy within a session at 6Pm and have it stop when 30kWh has been delivered.

Let us go through each of these available targets in a little more detail.

Energy Target

Energy (kWh): E.g A session is started via a POST /sessions API call with an E kWh limit.
eDRV attempts to stop a session when session.metrics.energyConsumed >= E*1000
(No default session energy target)

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Use Case: Session with an Energy Target

When charging a fleet delivery vehicle, refuel the battery with the expected energy required for a round trip delivery.

Time Target

Time (Minutes): E.g A session is started via a POST /sessions API call with a T minutes limit.
eDRV attempts to stop a session when session.metrics.energyPeriod >= T*60.
(Default session time target is 12 hours)

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Use Case: Session with a Time Target

Where operators prefer to discourage drivers from squatting on a connector.

Vehicle State Of Charge Target

State Of Charge (SOC): E.g A session is started via a POST /sessions API call with a SOC% limit.
eDRV attempts to stop a session when session.metrics.energyPeriod.state_of_charge.value >= SOC.

NOTE: Only DC Chargestations report a vehicle State of Charge

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Use Case: Session with a State Of Charge Target

A fleet operator wants to top-up a vehicle to a target State of Charge %.

Cost Target

Money (Amount): E.g A session is started via a POST /sessions API call with a $M limit.
eDRV attempts to stop a session when session.cost.amount >= M
(No default session money target)

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Use Case: Session with a Cost Target

Prepaid EV charging, where the driver has paid for $M of charging.

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Accuracy of Session Target Detection (Energy, Time, Cost)

Please note that the chargestation sends energy reports every 30sec-1min to eDRV and it may take another 30seconds for the chargestation to respond to a session stop command from eDRV.

Because of this delay, consider adding some padding to the values when setting targets (Energy, Time, Cost) for a session. Most of the real-world charging sessions last for hours at a time in which case adding a couple of minutes (time) or 0.5 kWh (energy) padding to your targets may be advisable.

When testing with session targets with very short sessions (e.g. 2 minutes) please look out for unexpected behavior.