48 V – Four Times the Voltage

The latest technology making the rounds in the automotive world is a 48-volt system. This quadrupling of the onboard voltage from the earlier 12 volts reduces the current required for a given amount of power by a factor of 4 (P = U x I). A smaller current makes thinner cables possible. Considering the length and number of wires installed in today’s vehicles, the new approach results in a notable reduction in weight and thus fuel consumption.

A so-called mild-hybrid car will combine the technology with a newly developed, extremely efficient starter. In contrast to a traditional alternator bolted to an engine block, the latter can be integrated into new generations of motors and offer not only starter functionality, but also a start-stop system and a boost mode. In addition, it recovers energy from braking and coasting and stores it temporarily in a 48-volt battery. This kind of integrated solution makes the most sense in the luxury segment, whereas belt alternator starters could make it relatively easy to retrofit smaller vehicles.


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