Greater Efficiency for Light Trucks with Power Net Technology from Continental

At the heart of the design is a double-layer capacitor, also known as a supercap. These energy storage devices, which are new to the automotive sector, offer much faster charging and discharging rates than a conventional battery. “Even at very low temperatures, an almost unlimited number of cold starts are possible without overtaxing the electrical system battery. At the same time, all electrically operated on-board equipment, such as air-conditioning or navigation systems, will remain fully functional, even when a large amount of power is required to restart the engine,” explains Dr. Carsten Götte, Head of Development Power Net Systems at Continental, Division Powertrain. In addition, high-performance electronics ensure that the energy harnessed by recuperation becomes available to the system in a fraction of a second. This technology is not only adaptable and scalable in every respect, it is also compatible in terms of voltage with all established vehicle electrical systems worldwide.

Double-layer capacitor complements the conventional battery

Start-stop systems are one of the most cost-effective technical means of achieving a substantial reduction in fuel consumption in everyday driving. Delivery trucks that operate around town stand to benefit more than most. When the vehicle is stationary, for example at a red light, the engine is automatically shut down. However, frequent restarts place a great strain on the vehicle electrical system, the starter motor can briefly draw up to 600 amps of power. With conventional system architecture, this can mean that the engine cannot be shut down, because the active on-board electrical consumers are taking up so much energy that there is not enough available for restarting. Innovative Power Net Technology from Continental stabilizes these heavily stressed electrical systems. In developing the technology, Continental was able to draw on the applications engineering expertise acquired working on Peugeot’s eHDI models.

“Core of the technology is a double-layer capacitor with a capacity of up to 3,000 farads per cell – enough to handle several restarts in rapid succession,” explains Dr. Götte. “This method of storing electrical energy has the advantage of offering complementary characteristics to those of a conventional battery. It can store and discharge its entire energy content in just a few seconds, which makes it the ideal means of handling peak loads or storing the energy recovered by recuperation.” Such supercaps retain their performance at temperatures way below zero and can handle up to one million charging and discharging cycles. Based on Power Net Technology, Continental’s engineers have put together an energy storage system that also takes in the starter battery, combining the advantages of the supercap (high power density) with those of the battery (high energy density) to best effect. A battery controller governs the flow of energy to or from the respective storage device.

Scalable technology that can be integrated into any on-board power network

Power Net Technology is designed for scalability. The energy storage media can be connected in series or in parallel. The optimum configuration will result in each case from the existing system architecture. So in one case the supercap will complement the existing starter battery while in the next it will replace one of multiple batteries in a vehicle’s electrical system. The Power Net system can be integrated into any vehicle electrical system – even those that work with two different voltages. As a result, Continental’s high-performance electronics technology is already geared to future developments in on-board power networks.