Glossary

In hybrid vehicles, a small electric motor supplements the combustion engine. It recovers energy during braking ("recuperation") and stores it in a battery. On demand, the e-motor then supports the engine with additional torque and, optionally, to bridge the turbo lag - this is the boost function. In 48V hybrids, even the simplest implementation of this additional support features 15 kW / 20 hp.

When a hybrid vehicle switches to coasting mode (also called sailing or gliding), the combustion engine is switched off while driving and the transmission shifts to idle to save fuel. This happens automatically when the driver takes their foot off the gas. As soon as the accelerator is pressed again, the engine is restarted in a fraction of a second and the transmission re-engages.

Ever since the starter motor replaced the hand crank as a means of starting the engine in 1914, it has been one of the core components of the internal combustion engine. A good starter motor should be virtually invisible - in other words, it should start the engine reliably, smoothly, and quietly. Nevertheless, the process is noticeable.

The starter-generator in a 48V hybrid now makes cold starts and start/stop operations even smoother and faster by interacting harmoniously with the combustion engine.

In the car, there are a large number of devices, safety functions, and comfort features that require electricity – from radio and headlights to electric brake boosters and driving assistance functions.

These are powered by an on-board electrical system, which in vehicles with conventional internal combustion engines operates at 12V. In mild hybrids, it is supplemented by a 48V electrical system. This reliably supplies current to safety-relevant high-performance consumers and enables comfort functions such as roll stabilization or a windshield heater. Furthermore, the 48V hybridization offers additional driving functions such as comfort start, boost, and coasting.

The European Union has imposed increasingly stringent emissions standards for vehicles with internal combustion engines since 1992. These regulate emission limits with regard to pollutants such as carbon monoxide.

Euro 7 is the forthcoming emissions standard, the details of which are currently in negotiations. In order to meet the more demanding regulations and limits, it may become necessary to preheat the catalytic converter, for example. This would significantly reduce the particularly high pollutant emissions during cold starts.

Recuperation means energy recovery. In Formula 1, the KERS ("kinetic energy recovery system") has been around for years. It converts kinetic energy into electrical energy during braking, andlater releases it as an additional boost during rapid acceleration. This technology made the leap to regular passenger cars at the end of 2016. In the simplest implementation form, a 48V recuperation machine replaces the conventional 12V generator in its installation space on the belt. This gives the vehicle additional power and can save 15 - 25% in fuel consumption and CO₂ emissions.

More about 48V hybridization

A conventional internal combustion engine is always equipped with a starter motor and an alternator (also called a generator). The starter motor gets the engine running and the alternator generates electricity for the on-board electrical system while the engine is running.

A starter-generator combines these two tasks in one component. A 48V machine such as the BRM can replace the alternator in its installation space on the belt. It takes over the power generation while also providing a smooth engine start. Through recuperation, the 48V machine can even recover kinetic energy during braking saving 15% or more in fuel and CO₂ emissions compared to a conventional combustion engine car.

The spatial relationship of objects to each other is also called topology. In cars, this refers to the placement of components within the powertrain. For mild hybridization of passenger cars, there are five different positions at which a 48V machine can be integrated. These are termed from P0 (on the belt) to P4 (on the rear axle).

More on the different topologies of 48V hybrids.