How do I keep a car battery from dying if the car is not used often?

A battery maintainer delivers a continuous low-level charge that keeps the battery topped up without overcharging. It is the most reliable method for vehicles stored for weeks or months at a time.

Running the engine periodically lets the alternator recharge the battery, counteracting both self-discharge and parasitic drain from onboard electronics. A short drive is more effective than idling alone.

Removing the negative cable from the battery physically isolates it from the car's electrical system, stopping parasitic drain from clocks, alarms, and onboard computers. This is a simple, zero-cost way to slow discharge during storage.