When Valiants Overran San Francisco

What did they do to make them "battery saving alternators"?

Installed them as standard equipment instead of DC generators. The '60 Valiant was the first car on the American market with an alternator as standard equipment. Chrysler's alternators weren't super-strong at idle, but they did give about 10 amps, which was 10 amps more than a DC generator at engine idle.