According to Edmunds, a car may sit anywhere from a few weeks to a few months before the battery depletes enough to prevent starting the car. Because an older battery may drain in a few weeks, driving the car every two weeks should keep the battery charged.
Although a typical car can sit between a few weeks and a few months before the battery loses its charge, the automotive website Type 2 notes that small electronics in the car can deplete the battery more quickly. Parasitic loads like security lights, aftermarket alarm systems and clocks can run down a battery.
Under typical conditions, starting and driving a car at least once every two weeks should keep the battery sufficiently charged. Drivers with a lot of electronics in the vehicle, though, should start and drive the car more frequently.
