Q: My 2010 Mazda 3 hatchback's battery has died. When I get into the car, it sounds like something is on, when nothing is on.

Late model cars use a lot of power while the key is off. We call that "parasitic drain." In normal cases it doesn’t exceed 200 milliamps and at that rate the battery should stay alive. Like your computer, your car goes through a shut down procedure that takes about 20 minutes and sometimes when something goes wrong, not everything shuts down as it should. This can drain a battery overnight. Figuring out what is not shutting down can be challenging and requires a pretty thorough knowledge of your cars systems. To have it checked out at your convenience, contact YourMechanic. They can send a technician to your home or office to check out your electrical system and let you know what it will take to solve your problem.