Back in our July 2000 issue, we briefly looked at the way in which vehicle electrical systems are changing. The use of high-output alternators and 42V electrical systems were being mooted as technical solutions to the ever-increasing electrical power demands in cars. What’s happened since? Well, in a few words – a lot!

General Motors see the inclusion of 110VAC power sockets in their mild hybrid pick-up truck as a major selling point of hybrid technology. The circuits are protected by ground fault detection and up to 14kW is available.

Toyota in Japan currently sells a car with a 42V electrical system, while GM in the US is this year releasing a 42V pickup truck – and some organisations are already using pre-delivery vehicles. New technical standards are being developed to cover everything from 42V battery terminal and fuse design to the colour-coding of 42V wiring. Automotive component suppliers have developed 42V alternators, starter motors, circuit breakers and other components. Some are predicting that by 2010 as many as half of all vehicles will use 42V electrical systems. In 20 years, the forecasts suggest that all cars will use this voltage.

Even more interesting is the relationship developing between "mild" petrol/electric hybrids and 42V electrical systems. Throw in the increasing availability of mains power in cars (yes, that’s right – in the USA you can now have a factory-fitted mains power socket in your car!) and the whole area of car electrical systems is undergoing a change of a magnitude never seen before.