The battery in Little Red exploded when I tried to start it after it had been driven 30 miles or so with a overcharge of 15.5.

You shouldn't get any more than 14.5 volts on your meter while the engine is running. A fully charged battery can register 13.3 or thereabouts, but 12.86 is considered fully charged

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)