SYSTEM OF PROPULSIONSYSTEM OP PROPULSION - Google Patents
Patent number: 1095967
Filing date: Nov 7, 1910
Issue date: May 1914
This is a great innovation. A car with 2 batteries, a small combustion engine a generator and an electric motor. The combustion engine is used to power the generator. One battery is charging the other is powering the car. The battery with the lowest voltage is charged first. If demand in current goes up the generator and the charging battery supply extra power. Because the voltage of the batteries is almost the same they can be switched in parallel without the one charging the other.
The patent is from 1910, today we have capacitors and batteries good enough to make this charge/discharge system.