Battery in a 1973 Volkswagen Super Beetle?

Sounds like voltage regulator is not disengaging and overcharging your battery. Check with a voltmeter with nothing on to insure return voltage to battery does not exceed 14.75 volts and drops to 12.65(roughly) after battery is fullly charged. With a fully charged battery the voltage regulator should disengage within 5 minutes. Autozone can check it in the car if you take it there.