[Piwoslaw]

Originally Posted by RobertSmalls

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.

I believe that 50V is the "safe limit", that's why we see RE systems (PV, wind) up to 48V, but not many at a higher voltage.

IIRC in the old days cars had a 6/7V system, which got beefed up to today's 12/14V (can't remember which year). In the 1990's there was talk about using 36/42V for all of the "power" accessories (windows, steering, heating). The higher voltage would also open the way for mild hybrids. There would still be a 12/14V system for many things, as lighting is supposedly more efficient at lower voltages.

Extra weight of a 36/42V system? Many cars already have 2 batteries (first example off the top of my head is the Peugeot 607) as 1 would have a hard time with all the electric/electronic gadgets. One more battery in a 2-3 ton luxury car or SUV will hardly make a difference. In fact, the extra 20-40 pounds would hit FE hardest in city driving, where the gains from an engine start-stop or mild hybrid system would be largest.