She let it sit for a year! Both batteries died!

Leaving a car parked and unused for an extended period, like a whole year, can lead to unfortunate battery issues. Both the main car battery and any secondary batteries can fully discharge if not maintained, often resulting in a no-start condition. From my experience, modern car batteries slowly lose charge over time through a process called parasitic drain; electrical components such as alarm systems, clocks, and onboard computers draw power even when the car is off. Exposure to cold temperatures during storage can further accelerate this discharge. To avoid this, it’s crucial to either start and run the engine periodically or disconnect the battery if you expect the car to sit for months. Using a smart battery maintainer or trickle charger is another highly effective way to keep the batteries in good shape over long periods. Regular checks are recommended as well, since a completely dead battery often can't be revived and needs replacement. When dealing with a dead battery roadside, having access to reliable roadside assistance can save considerable time and hassle. Sometimes, jump-starting may help, but severe battery failure might require a tow or battery replacement. Remember, preventive care before leaving a car unused is always better than emergency fixes. Taking simple steps can extend battery life and avoid the common frustrations of dead car batteries after long storage.