My '07 Limited Coupe still has the original factory battery in it. But I only have a little over 12k on the ODO. So the car sits most of the time. When we do drive it occasionally around town, the alternator doesn't have enough time to "charge -up" the battery. So every 6 months or so, I hook up the battery charger to the factory battery and let it get a good charge during a weekend afternoon. So far no battery-related starting issues.