What current solutions are there and why is wired charging still the better option?
Today, our smartphones are our constant companions, regardless of whether in our free time, at work, or in vehicles. In order to be able to use many functions of the smartphone such as radio, music streaming, and navigation in the car, the smartphone must be able to communicate with the vehicle somehow.
Here, you often encounter questions such as: Do I need to use a cable to connect my mobile phone to the vehicle or can this be done wirelessly? Where do I find the USB port to connect my phone? Do I have an adapter cable with me? If so, is it the right cable with the appropriate connectors?
Of course, then people ask the question whether a wireless connection between the vehicle and smartphone wouldn’t be better. It is precisely this question that we want to answer in this blog post. Here you will learn what possibilities there are at the moment for connecting smartphones to a vehicle and which functions you can use this way.
What does “wireless” mean?
Essentially, the term “wireless” comes from telecommunications and describes wireless signal transmission via electromagnetic waves.
With wireless charging, the energy is transmitted inductively, that is, via moving magnetic fields, between the sender and receiver. For this purpose, both devices (charging device and smartphone) must have the appropriate equipment.
With regard to wireless charging, there are four different types:
- IR wireless (data transfer via infrared radiation, restricted range),
- Fixed wireless (modem-bound, home and office areas),
- Mobile wireless (wireless, permanently installed devices such as car telephones), and
- Portable wireless (autonomous wireless devices with rechargeable batteries, such as mobile phones).
The Wireless Power Consortium – the standard for wireless charging
Since 2008, the WPC (Wireless Power Consortium) has focused on the development and maintenance of standards for a wide variety of wireless power applications. This open group, which meanwhile includes more than 400 member companies from all industries, is working on the large goal of making all wireless charging devices and wireless power sources around the world compatible with one another. Against the backdrop of continuously developed, portable devices and applications, such as laptops, tablets, drones, and kitchen devices, a common, up-to-date standard makes complete sense.
The best-known standard in this area is surely the Qi standard (pronounced “chee”), which is used primarily for charging smartphones. With the baseline power profile, currently small electronic devices can be charged with up to 5 watts; with the extended power profile, the charging application can handle up to 15 watts. The members of the WPC are working on optimizing the power profile in order to be able to charge laptops and notebooks with the same technology in the future. Here, power levels between 30 and 60 W are being striven for.
The Qi standard includes worldwide certification for wireless devices and thus ensures that all Qi-certified devices are compatible with one another, regardless of their manufacturer, country of origin, version, or other factors. And the safety considerations with regard to heat protection and foreign body detection also play an important role.
Integration of smartphones into the vehicle’s infotainment system
At the moment, there are two basic ways in which smartphones can be integrated into the infotainment system of modern vehicles. On the one hand, there is Android Auto for incorporating smartphones with the Android operating system, and on the other hand, CarPlay for incorporating iOS-based iPhones. The somewhat older MirrorLink application no longer plays an important role in recent vehicle generations; however, it is still used in many cars and smartphones.
MirrorLink (developed by the Car Connectivity Consortium) describes an interface for data transmission between a vehicle’s infotainment system and a mobile end device. Connectivity is used primarily for navigation and media playback, in that particular (conforming) apps on the smartphone interact with the vehicle’s infotainment system (IVI – in-vehicle infotainment) and their user interface appears on the display. These application programs are controlled by various switch elements in the cockpit or via the display.
The goal of the Open Automotive Alliance, which was established in 2014 under the leadership of Google and the chip manufacturer NVIDIA, is and was to put Android Auto in vehicles, optimally as a real, independent operating system for the infotainment system.
Under the general term “Android Auto”, we currently make a distinction between different versions such as
- Android Auto (mirrors smartphone apps on the display),
- Android Auto for smartphones (stand-alone app that can only be used on the smartphone), its successor Google Assistant Driving Mode (mirroring on the display, two apps can be used simultaneously, only portrait format), and
- Android Automotive (complete operating system for infotainment).
As the latest development from Google, in the future Android Automotive should serve as an independent basic operating system (no smartphone required) for infotainment, dashboard, and climate control in the vehicle. Volvo and Polestar are already using this system. Developments on the system platform are underway at Fiat Chrysler, among others. General Motors is also considering using it.
For a long time, the connection between mobile device and vehicle was only possible with a USB cable. More recent vehicle generations support a wireless data transmission via Wireless Android Auto or Android Auto over Wifi with a 5 GHz Wifi connection. The telephone function still works via Bluetooth. For the initialization of the wireless connection, it must be possible to establish a one-time connection between smartphone and vehicle with a USB cable.
The essential advantage of Android Auto is surely the consistent operation and look, regardless of the vehicle and a simple, clear display of the functions. In addition, the same database in the cloud can be accessed in the car and from the smartphone.
Basically, CarPlay functions just like Android Auto, with a few minor differences. CarPlay is integrated into nearly all brands of vehicles, with the exception of Tesla (status as of March 2022).
The advantages certainly include Apple’s intuitive operating concept on the optimized CarPlay interface for displays and the innovative voice control (Siri – Speech Interpretation and Recognition Interface), with which most functions such as telephony, music, news, and navigation can be operated without a great distraction factor (use of the hands). This definitely provides added value, including the important safety factor.
Apple is also approving more and more third-party apps for CarPlay such as Google Maps. This way, people can save additional costs for an expensive infotainment system when purchasing a vehicle.
Via CarPlay wireless, it is possible to establish a connection between a smartphone and vehicle via Bluetooth and Wifi. Of course, a wired connection is also possible.
Another advantage is the CarPlay update function, including newer functions, directly via the iPhone.
The only noteworthy disadvantages of CarPlay are the restricted functional scope with regard to vehicle functions such as climate control and the number of available apps, which is still somewhat restricted. However, according to the announcement at WWDC 2022, from autumn 2023, there will be a new version that can also control climate devices. Porsche and Audi have been named as partners.
Advantages and disadvantages of wireless solutions
A great advantage of wireless approaches is that there is no need to plug in peripheral devices. In the same vein, as a user, you no longer need to keep additional cables in the vehicle interior.
Furthermore, the charging ports for smartphones are saved and you don’t even need them. Thus, a weak point, namely regarding dust and water protection, is reduced. In contrast to wired solutions, where you always have to have the right cable with the right connectors, with the Qi standard, you can combine all possible manufacturers and brands (charging device and mobile phone) since most devices will be compatible with one another.
The biggest disadvantage of the wireless approach is the relatively low charging power that can currently be transmitted. As mentioned before, the maximum charging power is 30 to 60 watts. At the same time, the amount of power loss – in the form of heat – is pretty high. Current USB applications can provide up to 100 watts (via cable) and for new generations, up to 250 watts may be possible. Due to the lower effectiveness as compared to cable connections, however, you have to make enormous compromises when it comes to charging speed. There is no quick charging here. The heat generated by charging also certainly does not have a positive effect on devices’ rechargeable batteries, which is why greater wear is likely. In addition, the mobile phone must be positioned precisely in the charging compartment to ensure perfect charging. If it slips due to slight shocks, the charging process is interrupted – and this without informing the vehicle’s passengers.
Surely something positive worth mentioning is the wireless data communication between the mobile end device and the vehicle or the respective control unit via Wifi or Bluetooth, as this already works perfectly. Here, many applications can be transferred to the multimedia system, and you can forgo wired solutions with a clear conscience.
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Wireless vs. wired connection between vehicle and smartphone
Secure is secure: wired connection
The more reliable and effective charging possibility is surely a direct connection of the smartphone to a USB charging module developed for this purpose via an adapter cable. Such modules are installed as standard with a charging power of up to 100 watts in single or double ports in vehicles.
In order to save a bit more space on the dashboard, you can also rely on so-called offset solutions, where only the customer interface is installed on the dashboard and the associated electronics are “hidden” somewhere else (e.g. in another control unit).
Summary and conclusion
In summary, it can be said that the wireless charging function is a completely practical feature that still has potential for improvement regarding charging power and effectiveness. Wired charging is definitely the more secure and effective option if the concerns are speed and security.
When it comes to wireless data transmission (Android Auto, CarPlay), there has been a lot of progress. Communication with the vehicle works very reliably via Bluetooth and Wifi, and all necessary applications can be transmitted to the infotainment system. Only for the initialization of Android Auto is a cable connection required.
Android Auto im Test: Funktionen, Apps, Auto-Hersteller, Varianten – PC-WELT (pcwelt.de)
Apple Carplay im Test: Funktionen, Apps, Anbieter, wireless Carplay – Macwelt
Induktives Qi-Ladegerät im Auto: Wozu? | mobile.de