The advent of 48V technology within the automotive industry, and with major OEMs like Delphi forecasting fitment to 10% of all new cars by 2025 – 11 million cars per year, it would appear it’s here to stay.
A need for an additional voltage level was identified several years ago as vehicle manufacturers rushed to develop hybrid vehicles to meet the emissions reductions targets imposed by global legislation. The need to enable greater power loads from components such as power steering pumps, electrical heating systems, and compressors was compelling, but some components and systems, while requiring the higher voltage level, are not required to be permanently on. This is important as energy efficiency is the key; if a system doesn’t have to be switched on and using energy, then it should be switched off but available on demand. In addition, this voltage enables the “KERS” type systems used in Formula 1 to be suitable for a small family hatchback and also enables an air-conditioning system to get the car heated up or cooled down far quicker than a conventional system.
The Audi SQ7 has debuted the first 48V electrically powered compressor to support the two turbochargers on its 4.0 V8 TDi, and both the SQ7 and the Bentley Bentayga use 48V to enable active body roll stabilisation systems. It’s a win-win situation with the vehicles manufacturers having a technology that helps them to get nearer the emissions and environmental legislation, and the consumer gets a hybrid car with better performance. For electric compressors, such as that from Audi, there is no real “lag” which makes for a more responsive vehicle. The same can be said for the active roll control systems for the Audi SQ7 and the Bentayga; the 48V system enables faster responses and better body control than would otherwise have been possible.
Additionally, by replacing a conventional starter motor with an electric motor that they’ve titled a “Hybrid Starter Generator” (HS) on a Tucson Hybrid concept, Hyundai has sown the potential for a “mild hybrid” system. The HSG supports the engine during acceleration, but then becomes a generator during deceleration. This system weighs just 20kg, boosts engine power by 10%, reduces emissions “significantly” and yet is far cheaper than a conventional hybrid system, some reports suggesting as much as a 75% reduction in cost.
As this growth in 48V technology takes off, it won’t be too long before body shops will be faced with repairing cars featuring this system. We are already seeing this technology from Bentley and from Audi and a concept from Hyundai. But this is coming in volume, as a great number of OEM and vehicles manufacturers are developing the technology and assessing the potential applications. As we’ve already seen, it can enable advanced body control system on high-end vehicles, more efficient electrical air-conditioning for hybrids and EV, and low-cost mild hybrid systems for family hatchbacks, 48V is already often referred to as “the people’s hybrid”. This is very much the one to watch as it is a good solution to a good many technical and legislative challenges for the automotive industry.
It’s important to be aware, however, that these will not replace 12V architecture (at least, not yet) but will instead be alongside these within the vehicle’s electrical system. It’s even more important to be aware that they need to be kept in use in the event of an accident and repair. A bridge or arc between the 48V and 12V systems will get very expensive very quickly as pretty much every 12V component will need replacing.
Over the coming months, Thatcham Research will be investigating this technology and its challenges in far more depth to ensure that when it does impact the volume market, we are ready to support with the appropriate technical information and training needed to allow the body shop of today to become the body shop of the future.