At Chargetrip we have learned a lot about electric vehicles (EVs) during the development of the Chargetrip EV routing engine. For anyone who wants to learn more about the topic or external developers who are starting to work with the Chargetrip API, we want to share our knowledge and get you familiar with the new EV routing paradigm.
In this article, we will first discuss how EV routing differs from routing for internal combustion engine (ICE) vehicles. Secondly, we will delve into battery range and how car characteristics can impact it. Third, we will talk about connector types, charging speed and how they affect the computation of routes.
In order to start building the next-generation of electric mobility tools, it is important to understand what aspects of driving an EV are different from driving a car with an ICE. Routing solutions for ICE only need to consider origin and destination. Finding somewhere to fuel is simply not a difficult issue.
With an EV, this is different. When driving an EV from A to B you need to bear much more in mind: when to charge, where to charge, how long it will take, check whether you can activate and pay at that charge station, how to spend your time while charging, and whether there aren’t any alternative or faster routes via different chargers.
For EV routing, drivers not only want to know how to get from A to B, but more importantly, they need to know what the optimal charge stations are in between. Refueling or charging is a core part of the end-user experience and significantly impacts the planned journey. The compound challenge is that the optimal charge stations on that same route from A to B will differ, depending on the EV make and model you drive (since all EVs have different energy consumption models), the battery level of your EV when you depart, what the weather is like, and the real-time (dynamic) availability of the different charge stations.
For this reason EV routing at its very basic requires four inputs:
The EV model
Current state of charge (SOC) of the EV
With these four input variables, the Chargetrip routing engine can compute the best route, including the optimal charge stations along the way.
The Chargetrip routing engine takes into account all the characteristics of your vehicle, what we call a car profile; its consumption under different circumstances, the optimal charge speed for the EV, payment profiles of the driver, outside impact variables like weather, temperature, and elevation; the dynamic availability of a charge station and driver preferences like amenities at a charge station. The result is a predictable route plan for EV-drivers, giving them the confidence and ability to use their EV as their primary car.
Range of electric vehicles
All EVs have a battery with fixed capacity and consumption. There are two dominant types of range measurements for EVs:
EPA range measured by the U.S. Environmental Protection Agency;
WLTP range measured by the Worldwide harmonized Light vehicles Test Procedure.
The tests are conducted in a controlled environment where all the variables that affect the range are predefined and fixed. This means that the actual range for each EV can be different depending on various factors, for example the weather condition, terrain, elevation, the number of passengers in the car and more. The Chargetrip routing engine uses these and many more dynamic variables to calculate the range.
It also includes over 120 active car profiles with sophisticated corresponding consumption models. This way we are sure that our routing engine computes the most optimal route for that specific car in a specific time frame, and navigates the driver to suitable charging stations.
Charging of electric vehicles
As mentioned earlier, charging an EV is fundamentally different from refueling an ICE vehicle. You also need to consider that every electric vehicle comes with its own connector (also called plug or connector standard). Multiple standards for connectors exist, as well as for power throughput.
Connectors & standards
The most common connectors for electric vehicles are CHAdeMO, Type 2 (J1772 in USA) and CSS. Each plug has a different pin layout and supports different types of electric current — AC or DC. If your car has a certain connector but you need to connect to a different type in order to charge, you could use an adapter. The Chargetrip routing platform takes into account what connectors are supported by a car and all plug adapters a car owner may have.
The battery of an EV has a fixed capacity expressed in kilowatts and supports different types of chargers. There are three types of EV chargers that correspond to different power outputs. Chargers that are up to 25KW/h, from 50 to 100 KW/h and from 150 to 350 KW/h. Each of them has a different charging speed.
Chargers with a maximum capacity of 25 KW/h are considered regular or slow chargers. These chargers can mostly be found at places where a car is parked for many hours. A good example is a domestic charger at a parking space next to your house, where you will leave your car overnight. Chargers from 50 to 100 KW/h are considered to be fast chargers. These are the type of chargers that you would usually find along the highway.
The fastest chargers go from 150 to 350 KW/h. These chargers can charge the battery to 80% of the maximum capacity in around 20 minutes.
The Chargetrip Platform & EV Routing algorithm
In this article we have outlined how EV routing is fundamentally different from routing for ICE vehicles. We have read about the main variables that affect EV range, and learnt about the different types of chargers and connectors on the market. When computing an optimal route, the Chargetrip API takes these and many more variables into account, including user preferences.
You can learn more about building a route and all the configurable parameters in our API reference.
Throughout this article we have described the different standards that exist in the EV ecosystem. Now that the EV market is getting more and more mature, the different standards are being evened out. It is important to know that the Chargetrip API follows the Open Charge Point Interface (OCPI) standards. So when you start building EV routing solutions you can find the OCPI names for connectors in the official reference.
Before you start developing amazing EV tools, let’s make sure we all speak the same language. Below, you will find a list of acronyms you will often encounter when dealing with electric mobility.
AC/DC — Rock band. 🤟
AC — Alternating Current. The current reverses, alternates, on a regular basis. (Europe: 50 times / second, US: 60 times / second).
DC — Direct Current. The positive and negative terminals of a battery are always, respectively, positive and negative.
EV — Electric Vehicle.
CPO — Charge Point Operator.
EVSE — Electric Vehicle Supply Equipment. Charge station or charging point.
EPA — Environmental Protection Agency. Government organization in the US that measures range for EVs. EPA range is the range issued by this organization.
ICE — Internal Combustion Engine. Engines in which fuel and oxygen are burned to an oxidized gas mixture that sets the engine in motion. When we speak about ICE vehicles we mean traditional fuel powered cars.
OCPI — Open Charge Point Interface. Open standard for charge points created by The Netherlands Knowledge Platform for Charging Infrastructure (NKL). The NKL is an independent not-for-profit organisation, set up by EV market players, Dutch central and local governments, universities and grid operators, with the goal to lower the total cost of the charging infrastructure and promote measures for the development of a mature market for EV.
WLTP — Worldwide harmonized Light vehicles Test Procedure. Standardized testing method for EVs. WLTP Range is the range measured by this testing procedure.
Where to go next?
The EV ecosphere is new and can sometimes feel a little bit complicated. We are sure that after reading this article you will have a very good basic understanding of EV routing. If you feel like you are missing information, do not hesitate to get in contact with us.
Learn more about the Chargetrip EV Routing Platform in our documentation.