Economical efficiency is widely regarded as the most significant factors for enabling a more widespread adoption of electric cars. High battery costs are one of the key reasons why electric cars are so expensive, prompting automakers to try and develop cheaper, durable batteries, and invest in the EV charging infrastructure. These are some of the goals of the RheinMobil project, which has been created as a joint effort between Fraunhofer Institute for Systems and Innovation Research (ISI), French tire manufacturer Michelin, Karlsruhe Institute of Technology (KIT), Siemens, and e-Motion Line, a German company that provides mobility services.
The RheinMobil project aims to find out how electric cars can be used in a more economically efficient manner, and help reduce the costs of owning an electric vehicle. Over the past few months, researchers have been trying to determine how different charging methods affect EV batteries and utilization rate of the vehicles. They have employed six minibuses with seven seats each, along with one compact vehicle, with each of them traveling about 1,800 miles per month, in an effort to see how much they can help reduce CO2 emissions, and which charging technology provides the best protection for car batteries.
During these commutes, researchers are using two charging technologies: quick charging and conventional charging.
The difference between Quick and Conventional charging
With quick charging, a car’s battery can be fully recharged in less than 30 minutes, whereas conventional charging recharges a battery in about nine hours. However, quick charging puts much more strain on the battery, reducing its lifespan drastically.
On the other hand, conventional, or slow charging, recharges the battery in a more balanced manner, at 230 volts of alternating current, thus reducing the effect on the battery’s life expectancy. This means that using fast charging exclusively will cause EV owners to replace their cars’ batteries with new ones much more frequently, which probably very few of them can afford, considering that they can cost anywhere between $2,000 and $3,000.
But, recharging your car through a conventional charging station only is not very convenient, since it takes a lot of time and requires breaks of 8-9 hours during longer trips.
What researchers have discovered
This is why researchers with the RheinMobil project suggest mixing these two charging methods. “The first 100,000 km (62,000 miles) yielded an important result: Although quick charging is the prerequisite for a high utilization rate, we cannot entirely focus on this technology. The right approach is to use the controlled mix of both quick and conventional charging. In this way, a high vehicle availability can be brought in line with the sustainable use of this technology”, said Dr. Kevin Stella, one of the project coordinators.
According to the RheinMobil team, the ideal solution would be using conventional charging whenever possible, such as when the vehicle is not being used for several hours, and only use fast charging when there is no time for longer stops.
These findings provide can be of great use to EV owners, who are looking for ways to strike a balance between having their vehicles recharged relatively quickly, and prolonging the life of their batteries.