|
The voltage has to be high enough to drive high-power devices with reasonable amperage, but not so high that it presents a hazard to your mechanic.
Another big application for higher voltage systems is large starter/generators. That would allow the engine to stop at idle, and start up in a few hundred ms so the system is not disruptive. A really big alternator also allows you to do most of your charging while the driver wants to slow down. The underwhelming Chevy Malibu Hybrid did this with an auxiliary 48V NiMH electrical circuit, which means that system required two batteries, plus a 48V->12V DC-DC converter, both of which add cost.
The downside of changing the voltage is that everything electrical on the car will have to be reengineered. New part numbers for every bulb on the car, you'll need a 48V radio and instrument cluster, and even the throttle position sensor and ECU will need to be revamped. If you want a 12V power socket, that will require a small 12V power supply.
|