16 volt battery?

[JeffPeoples]

As posted earlier, charging systems output above battery voltage. They must do so, to get the energy to go "back" into the battery. Many racers using 16 volt batteries are not running alternators, so the max voltage the electrical systems see is 16 volts. They do make alternators that are designed for 16 v batteries, and they put out over 18 volts. This pushes the bounds for many electrical components.
Don't know much about the roundy round guys, but the drag racers are looking for the extra voltage to give them a bit more horsepower from the extra ignition output (easier starting is a bonus). The analog MSD boxes can handle the 16 volts, but don't like the higher voltage alternator output. In fact, cars without alternators must make sure the master switch is off when in the pits on the 16v charger between rounds, so as not to kill the MSD.
TurboStart sold step down boxes that would output small amperages of 12 volt power for misc accessories, but they are prone to failure. They also had batteries with a 3rd lug that one could get 12 volt power from.
Since pro touring is about so much more than just horsepower, and these types of cars tend to have a lot of electrical accessories, I would really cautious about 16v batteries in a street oriented car.