Q: Why does the battery go dead if you forget to use park? 2013 Ford Edge

Hello - newer cars are designed with convenience features that keep certain systems (radio and other infotainment systems) "active" UNLESS the car is in Park. This means there is an on-going battery drain, which will run your battery down after a day or two. Most of these systems keep things active for 5-10 minutes, then shut down electrical loads - but ONLY if you are in Park. If your vehicle still drains the battery when storing it in Park, there is a problem with a parasitic drain on the battery, and I would recommend an electrical inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.