Texas Jim
Texas..It's a Whole 'nuther Country
The one in the car is the original battery....
Car was built in March of 2006... so the battery was built even before then...
6 years on a battery isn't too bad.. and if I didn't forget to turn off the radar detector and cell phone charger all the time.... I probably wouldn't need a battery now.
Neither one of those should be enough to kill a battery.
You should be able to leave 'em both on for several days and still start the car.
I've also had no luck with Delco batteries. The two that came in my truck were both less than three years old when I got it, and would barely turn it over. True, they were a little undersized (675cca) for a diesel, but they were what the GM book called for. Swapped 'em out for a pair of Kirkland (Costco brand) 800cca batteries and it's been cranking like a champ.
The car sometimes don't get started for a week or more at a time...
It just sits in the garage...

When it was new... it took 2 weeks to kill the battery..
A couple of years ago it took at least a week.
Yesterday it had only been sitting for a little over 3 days...and it was dead...
Had to put the battery charger on it for a few minutes to get it to start...



At least it stayed clean for 4 or 5 days!