How do we get from point a to point b? Thanks to the invention of the electric bike, not to mention its hip cousins like the monowheel and the e-scooter, there are more answers to this question than ever. New means of transportation are undermining the supremacy of the car, but they also present manufacturers and users with challenges. How do you ensure, for example, that the batteries of all the different kinds of e-bike can easily be charged everywhere?
Electric bikes are hot property. Last year, half of all the bicycles sold in Belgium were powered electrically. The rise of speed pedelecs is particularly notable. These are e-bikes that can go up to 45 km per hour: ideal for commuting, as increasing numbers of commuters are discovering. In June of this year, 33,090 speed pedelecs were registered in Belgium, more than triple the numbers in 2018. This is a growth curve that leaves those of electric cars in the dust.
Professor Jan Cappelle, Head of the Energy and Automation Research Group at the Ghent Technology Campus, is an experience expert: he commutes 32 kilometres from his home in Waregem to the campus in Ghent on a speed pedelec. He thus also knows how important it is to be able to charge the battery in a user-friendly way. That is also what commuters with electric bikes expect from their employers.
Unlike for electric cars, there is no standardized charging process for electric bikes. Almost every brand has a different charger.
But it is easier said than done. Unlike for electric cars, there is no standardized charging process for electric bikes. Almost every brand has a different charger.
“It is often a question of making do,” Professor Cappelle says. “You have to take your own charger with you on your bike. They are heavy and at risk of breaking from the bumps. You can of course buy a second charger to keep at work, but they cost a few hundred euro. The charging infrastructure that employers provide often doesn’t consist of much more than a socket near a bike shed. You have to leave your charger unguarded and the cable usually just hangs loose.”
“There are also types of little letterboxes on the market in which you can keep the charger and sometimes even the battery itself. But due to the diversity of the batteries, these little boxes aren’t suitable for every type of battery.”
Professor Cappelle tells an anecdote to illustrate the fact that the inconveniences of charging electric bikes can cause considerable frustration. “For a number of projects, we lend electric bikes to employees of companies who want to test them. We once had a man who glued a pipe to the charger so that he could fasten it to something. It is quite telling that somebody would do that with an expensive, borrowed bike.”
Plus and minus
Things could be much better, the research group thought. For the project ULive (Universal Charging Infrastructure for Electric Bikes), they joined forces with twenty partners in the sector. The researchers analysed all the existing charging systems: which battery types, plug types, and communication protocols do they use? Checking out these protocols was rather like detective work because the majority of manufacturers prefer to release little or no information. The research group then used the data they could find to develop a universal, user-friendly charging system.
The result: a smart charging station that includes theft protection. “From the battery connection on the bicycle, we connect two cables to clamps on the front fork, which function as the positive and negative electrodes for the battery. When you push your front wheel between the two bars of the bike rack, your bicycle locks into place.”
“Both the bicycle and the charging station have a QR-code. You scan the code with your smartphone so that the system can identify the type of bike and other necessary information to charge the battery. The system has a central power electronic converter that converts the ac grid voltage into a dc voltage of 60V. Per bicycle clamp, a small charge regulator is connected to this 60V-bus that charges the bike battery according to the correct charging protocol. It is more efficient and cheaper than applying traditional chargers per bicycle.”
Users can monitor and control the charging process with an app on their smartphone. “This provides a solution to the irritation that users of electric bikes will recognize. It sometimes happens that people park their bike next to yours and accidentally bump your charger, making the socket fall out. When it’s time to cycle home, you realize: Damn, the battery isn’t charged. Our system notifies you if the charging process is interrupted.”
The app can also help companies to charge a large number of electric bikes as economically and ecologically as possible. Users indicate when they intend to leave, and the system ensures that the battery is full at that time. This allows for flexible planning of precisely when and how quickly the battery charges. For example, an algorithm can ensure that the charging process makes optimal use of the available solar power or prevents overloading the grid. In other words, it is a way to integrate electric bikes in the smart grid, the smart electricity grid of the future.
The benefits of the universal charger are self-evident. This model will not be released on the market as such. “The primary intention of this prototype was to show the partners in the project what all the options are,” Professor Cappelle says. “And we definitely succeeded: we have planted a seed. The idea of integrating a lock and the fact that bikes can play a role in buffering solar energy was an eyeopener to many of the partners. The project also exposed the problems of a lack of standardization.”
“We didn’t invent anything new as such, but we did demonstrate a new application of existing technology, while researching and answering a whole series of questions: how can we guarantee security with universal charging, what are the minimal requirements of a possible standard charging process, can we charge bikes more efficiently in bulk… This demonstrates the possibilities of new technology to a sector that is not familiar with it. To me, this project is an excellent example of the way in which industrial engineers can identify and solve problems.”