In-Vehicle Charging

Last edit: 2024.05.24

In-Vehicle Charging, specifically EV (electric vehicle) charging, plays an important role in the future of the Automotive industry, with more and more OEMs introducing electric vehicles to the market and countries all over the world investing in EV infrastructure. This change in the Automotive industry comes with additional complexity for EV drivers when it comes to managing routes, availability of charging stations, and travel time.

TomTom aims to reduce this complexity for EV drivers by offering an integrated solution for planning an optimal route that takes into account the charging needs of the car, available charging points (EVSEs) en route, and seamless integration with e-mobility service providers (e-MSPs). An e-MSP is a service that provides electric vehicle drivers access to charging points in a particular geographical area. Integrating an e-MSP with TomTom Digital Cockpit allows the driver to start and stop the charging process and to pay for charging using that service from within their IVI system without using a dedicated app on their phone.

TomTom Digital Cockpit provides an architecture that allows different e-MSPs to be integrated into the system at the same time allowing the end-user to pay for the charging transaction using different providers. Typically an e-MSP would be configured by a carmaker to be used in specific geographical areas based on the supported e-MSP and the agreements between the carmaker and the e-MSP.

Tomtom Digital Cockpit comes pre-integrated with Deftpower, an e-mobility service provider's app. This allows carmakers to provide their customers with the ability to charge their vehicle and pay for charging using only their vehicle dashboard with little integration effort compared to if they had to integrate an e-MSP from scratch.

A single common and consistent user interface is also provided as part of the TomTom Digital Cockpit application suite which allows the driver to charge their vehicle and pay for charging using different charging providers in the same way. Carmakers can opt to use this user interface in their in-dash systems, customize TomTom's offering, or provide their own to their customers.

In-Vehicle Charging Glossary

Many domain-specific terms that relate to In-Vehicle charging exist. This section provides a brief overview of the most important ones.

A charging station (location) is operated by a charging point operator (CPO) and contains one or more charging points. A charging point has an electric vehicle supply equipment (EVSE) and consists of one or more physical connectors of different types and power ratings.

Common abbreviations:

  • Charging Park/Pool: A grouping of charging stations that share a close location.
  • Charging Station/Location: A station is a physical grouping of one or more EVSEs, sharing a common user identification interface.
  • Charging Point/EVSE: Electric Vehicle Supply Equipment (EVSE) is the part of a station that will handle the charging process of one EV at a time. An EVSE may have one or several connectors but only one can be used at a time.
  • Connector: The connector is the physical interface connecting to the car.
  • CPO: Charge Point Operators install and maintain charge stations. CPOs can either own and operate Charging Park/Station or operate them for third parties.
  • e-MSP: e-Mobility Service Provider is a service that provides electric vehicle drivers access to charging points in a particular geographical area.
  • EV: Electric Vehicle.
  • OCPI: Open Charge Point Interface is an open protocol for communication between EV charging stations and e-MSPs.

High-level overview

The technical architecture of the In-Vehicle Charging domain within TomTom Digital Cockpit consists of three main layers:

  • The EV Charging frontend
  • The EV Charging platform services
  • The EV Charging e-MSP services

The first layer is the EV Charging frontend which comes with TomTom Digital Cockpit's application suite. This provides the driver with a user interface to search for a charging station compatible with their vehicle, select a suitable charging point, start charging their vehicle, monitor the charging process, stop charging, and see the cost of the charging session in a receipt.

In the second layer, there are the platform services called the EvChargingMediatorService and EvChargingStationService. The EvChargingMediatorService is responsible for controlling the access to the different e-MSP integrations in the system. The EvChargingStationService is responsible for providing additional information on charging stations to the mediator.

Finally in the third layer, are the IVI services that provide access to a specific e-MSP which comes with TomTom Digital Cockpit's application suite. These services would typically call the relevant APIs to access an e-MSP's cloud backend in response to user actions on the UI. For example, if the driver used the In-Vehicle UI to start charging their vehicle, then the EvChargingMediatorService from the layer above will select a suitable e-MSP from those available in the system and then the selected e-MSP service will call the relevant e-MSP's API to connect to the e-MSP's cloud backend to start the charging process.

The following diagram provides an illustration of this EV Charging architecture:

In-Vehicle Charging domain high-level overview image

An e-MSP can be integrated into the platform by creating an IVI service that implements the EvChargingService interface. This interface can only be implemented by discoverable IVI services and hence more than one can exist in the system.

The platform service EvChargingMediatorService internally holds references to all the known e-MSP integrations and mediates access to each of them. This service exposes the state of the charging session and can be used by the UI frontend to display the correct charging state to the driver. For example, it contains APIs that allow the UI to monitor when the user has an active charging session, and based on this state, it is possible to display a "charging progress" panel to the driver to monitor the current progress.

Integration with Navigation

Navigation will provide deep integration with the EV Charging domain. It will take the need to charge an EV into account when a route is planned and will add charging stops as waypoints during this route planning. All this is based on the current charge level of the EV. This reduces the range anxiety of the driver, reduces driving distraction, and makes sure that the destination is reached with enough charge left.


The waypoints added by navigation will contain charging stations. These charging stations will have an ID which needs to be understood by the e-MSP when requesting to start a charging session. To get the right charging station IDs the navigation API key needs to have the right entitlements.

EV Charging Station Entitlements

The same entitlements are needed for the navigation API key as for the EV Charging Station API key. This is to make sure that the charging station IDs provided by navigation are understood by the EvChargingStationService.

Interaction of modules and services

Starting a charging session involves several modules and services to work together. Navigation needs to indicate when the driver has arrived at a charging station, the EV charging frontend will provide the driver with the possibility to start a charging session, and the EV charging platform services will handle the charging request and start the charging session.

The interaction between all the modules and services is illustrated in the following sequence diagram: In-Vehicle Charging domain start stop charging image