Hint: Use a descriptive title for your new message If you're looking for help and want to draw people in who can assist you, use a descriptive subject title when posting your message. In other words, "2009 Genesis" isn't going to indicate to anybody that you need help. However, "Need help with my 2009 Genesis Sedan" will. Be as descriptive as you can. Please use common sense... This message can be closed by clicking the X in the top right corner.
I've had my ignition on (not just accessory) for about 40 minutes with stereo at an audible level just outside the car with windows down (not blasting). Started the car right up and let it run a good 15 minutes. I don't know if I would risk it longer than that - lots of electronics running on that thing.