I've done this adjustment, it works as Truckernix says. You'll want to set the voltage a bit over 9 volts. That said, expect to go through light bulbs a little faster. I've had no other problems with my 8 volt battery, but it is time for a new one, and I'll be screwing the cutout relay back to 7.2 soon!

Karl

It may not be the easy way, but it is the Cowboy Way - Ranger Doug
Beware of the stories you read or tell; subtly, at night, beneath the waters of consciousness, they are altering your world. - Ben Okri
1953 Chevy 3100
1960 Volvo PV 544
1941 Chevrolet Special Deluxe