48-volt auto-AC systems coming

Delphi is among a number of leading automotive component suppliers investing heavily in 48-volt electrical systems for hybrid cars in the quest for improved fuel efficiency and lower carbon dioxide emissions.

Citing figures from Global Insight IHS predicting that 48-volt systems are expected to be used in more than 95 per cent of the world’s mild hybrid cars and about half of all hybrid vehicles by 2025, Delphi claims 48-volt systems have already demonstrated they can offer at least 70 per cent of the benefit of high-voltage mild hybrids at 30 per cent of the cost.

Significantly, Delphi emphasises that air conditioning and other parasitic accessories such as power steering, water pump, active safety systems and heated items such as windscreen, seats and steering wheel, can be optimised by transferring the accessory load off the engine and on to a 48-volt system.

According to the company, the migration of high-friction belt-driven ancillaries such as the HVAC compressor and power steering pump from the engine to a 48-volt system will provide a more efficient and “on-demand” operating environment, providing a significant benefit for the world’s major vehicle manufacturers as they look to make incremental reductions in CO2 emissions. 

Delphi expects to have a 48-volt system available for production during 2017, combining with a conventional 12-volt electrical architecture, although demand is expected to increase as more sophisticated systems that can accommodate a wide range of components are developed over the next four years.

Air conditioning compressors are likely to be among the high-priority targets given their power requirements. 

Other companies working on 48-volt systems include Valeo, Continental and Bosch. 

Bosch recently provided an update on its work in electro-mobility, highlighting that a 48-volt system for hybrid vehicles “uses less expensive yet fuel efficient components, and enables additional comfort features as well as dynamic acceleration thanks to a boost function”.

It said the entry-level 48-volt hybrid is anticipated to be “a new attractive option for drivers in Europe, North America, and Asia” and that it expects some four million new vehicles worldwide to be equipped with the system by 2020.