42 Volt Is Coming...Eventually

The implementation of 42-volt systems in European automobiles has experienced numerous delays in recent years. The initial enthusiasm for the change has dampened as the high conversion costs become apparent. Nevertheless, the shift to a higher voltage is inevitable, it is just a question of when.

The switch to 42 volts requires significant changes to the electrical system of the car. With all the risks involved, the respective automakers are reluctant to be the one to lead the way. It now appears that the fuel consumption and emissions regulations in 2008 will be the necessary spur for change. According to the regulations, European automakers must reduce average emissions of carbon dioxide from 180 to 140 grams by the year 2008. This means a reduction in average consumption from 7.6 to 5.8 litres per 100 kilometres.

It is expected that the majority of European automakers will introduce 42-volt systems around the year 2008. Even then, it is likely to be implemented only in limited number of vehicles, mainly high-end vehicles and medium range ones which can gain the greatest advantage in terms of fuel economy. The majority of these systems will be dual voltage systems, with 14 volts continuing to be used for less high power applications. Pure, single voltage 42-volt systems will take even longer to appear, with the first ones being introduced at the end of this decade. They will not start to appear in significant numbers until after 2010. 

There will however be some dual voltage systems on the market even before 2008. The French carmaker PSA is expected to make the first steps next year with a dual 14/42 voltage vehicle featuring an integrated starter-generator. Hybrid sport utility vehicles made in the USA, for example by Ford, are expected to appear on the market in the next couple years. Toyota is also expected to be a leader in the introduction of 42 volt. They already have such a vehicle on the market in Japan, the Toyota Crown. 

The Japanese and the French have been the most active in pushing the 42 volt technology recently, while for example German carmakers have decided to adopt a more conservative approach. This situation is the reverse of a few years ago, when the Germans were the ones forcing the issue. DaimlerChrysler, who originally planned introduction for 2005, have postponed their plans. Audi have already introduced 42 volts for windscreen heating, using a DC/DC converter. However, this is only for an isolated application, and the majority of the functions in the car will still run on 14 volts. 

Although they have developed much of the technology necessary to introduce 42 volts, the philosophy of most automakers is to wait until there is a real demand for these systems. At the moment, their strategy is to push the 14 voltage based electrical systems as far as they will go. The fuel emission directives will provide the first real impetus for change. When there is an increased demand for other functionality, such as electric power steering and brake wire, then 42 volts will start to appear in larger numbers. 

Once the first systems are implemented, and some experience is gained, we will see a noticeable increase in the use of 42 volts. In 2008, it is estimated that around 1.3 million vehicles will be using 42 volt technology. By 2012 up to a third of all vehicles, over 5 million, will feature 42 volt systems. 



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