A 48-volt hybrid drive has gone into mass production and could revolutionise the future of hybrid automotive technology.
Jointly developed by German automotive tech giant Continental and French carmaker Renault, the 48-volt hybrid drive will make its debut in diesel production variants of Renault’s Scenic and Grand Scenic models this year.
Continental is claiming a world first for the technology, although a similar 48-volt is already being used in the Audi SQ7.
Continental claims its 48-volt system is a cost-effective solution to reducing fuel consumption and exhaust emissions. Dubbed by Continental as ‘Hybrid Assist’, the system replaces a conventional starter motor with an electric motor that pumps out 6kW permanently and 10kW temporarily via a belt that drives the crankshaft of the engine.
Conventional high-voltage hybrid systems operate at between 300 to 400 volts and are vastly more expensive than 48-volt systems.
Continental is predicting 48-volt hybrid technology will form the basis of the future of automotive technology, providing lower fuel consumption and emissions for only minimal costs. The German tech giant believes by 2020, four million vehicles will be using the technology.
Above: Continental’s 48-volt Belt Starter Generator
With Continental’s system installed in the new diesel Scenic, Renault is hoping to achieve a combined-cycle fuel consumption of just 3.5L/100km while also reducing CO2 emissions to just 92 grams per kilometre. This can be achieved because Continental’s electric motor also converts braking energy into electricity which can then be stored in a small lithium ion battery.
This energy is then used to help power the conventional internal combustion engine, offering as much as and additional 10kW of power and an additional 60Nm of torque. Additionally, the use of a belt drive means 150Nm of torque can be transmitted to the crank shaft, further reducing fuel consumption and emissions.
“We are proud that we were able to secure Renault as the first customer for our innovative 48-volt drive,” said José Avila, Continental Executive Board Member responsible for the Powertrain Division.
“Other production launches for both diesel and gasoline vehicles are in the pipeline for Europe and other markets including China and North America.”
One of the major benefits of the 48-volt ‘Hybrid Assist’ system is that due to its small size (it is no larger than a conventional starter motor), it can be fitted to any existing powertrain, making it a cheap and viable hybrid option.
The system has already achieved a 13 per cent fuel saving during stringent New European Driving Cycle testing but Continental is confident its system can achieve even higher savings in real world use – as much as 21 per cent. This is because in city driving, a greater percentage of driving is spent in the regenerative phase where the internal combustion engine switches off at speeds below 20km/h while the 48-volt system takes over coasting functions such as when approaching traffic lights.
Continental is now working on further 48-volt solutions that would see the electric motor placed between the engine and transmission which would allow for ‘pure electric’ driving in city areas.