After playing at the park for another 45 min, we got the family buckled and strapped into the Denali to go home and discovered that the battery was dead. Well, it wasn't completely dead--the lights, radio, windows, memory seats, power mirrors all worked. There just wasn't enough power to start the engine. Luckily enough, the first people to walk by had jumper cables and they were kind enough to help us get on our way.
Why did I use the Stabilitrak symbol for this post? Because I learned about how the GM stability control system works on the Denali. After getting jump started, the Stabilitrak light went on indicating a problem with the traction and stability control system. At first I thought maybe the next time I restarted the engine the light would go off. But when I got home and restarted the engine right away, the light stayed on. I thought maybe a blew a fuse when I was trying to crank the starter. But I couldn't find a fuse related to the Stabilitrak system.
So after hooking up the Denali to the battery charger, I took out the owner's manual and read the following information about the Stabilitrak system:
When you first start your vehicle and begin to drive away, the system performs several diagnostic checks to ensure there are no problems. You may hear or feel the system working. This is normal and does not mean there is a problem with your vehicle. The system should initialize before the vehicle reaches 20 mph (32 km/h). In some cases, it may take approximately two miles of driving before the system initializes.
If the system fails to turn on or activate, the StabiliTrak® light along with one of the following messages will be displayed on the Driver Information Center (DIC) (TRACTION CONTROL OFF, SERVICE TRACTION CONTROL, STABILITRAK OFF, SERVICE STABILITRAK).
If these DIC messages appear, make sure the StabiliTrack® system has not been turned off, then turn the steering wheel clockwise from the nine o’clock positions to the three o'clock position. If this does not clear the messages(s), then turn the vehicle off, wait 15 seconds, and then turn it back on again to reset the system.
Sure enough, after I disconnected the battery charger and restarted the Denali, the lights were off and everything was back to normal.
I didn't expect the battery to die so easily, but I guess I hadn't driven it very far each day this past week. And maybe the XM Radio/GPS antenna system uses extra power. I know I'm uncomfortable about everything retaining power even with the key out of the ignition. From now on I'm keeping own jumper cables in the back of the Denali.