Marty54

The LS460 is an electrical hog on the battery, all the electrical systems wear down that battery if your just going 3 mile short drives. Your car requires a certain load to start that car, and in the short few minutes of use, you have not enough charge time from the alternator to offset the start load. Do this about 3-4 times a day, and your battery is not going to survive more than 18 months. Do a couple long drives per month, and this should easily double your battery life. Remember that car batteries like to be used and then properly recharged. The longer drives successfully extend battery life.

Doublebase

Yes and I'll add, even someone like me (who drives 600 miles a week) has experienced premature battery failure. I think the problem with a car like this, is it's abundance of accessories. The telescoping steering wheel for example...how many amps does that draw? And it telescopes when the engine isn't running...which places the load directly on the battery. Same with the power trunk most of the time and the self closing doors...the puddle lighting, the alarm...all those things are draws on the battery and the battery alone. Yes the alternator will replenish the battery, but most cars don't experience these consistent demands when the car is off, this one does. It's not the keep alive memory that is a strain it's the actual electric motors that operate the steering wheel, doors and truck...that's a heavy load. In time it diminishes the battery's ability to charge. Today's battery's don't handle deep cycling very well, the plates are thin and the sponge lead eventually doesn't stick back on as much as it needs to.

I think the best bet is to buy a battery with a good warranty and from a place that will actually warranty it. That way you'll get it replaced for free or have it prorated. And the testing of the battery is also crucial...these hand held testers used to test a battery today go very easy on the battery, you'll get a lot of false passes with them. However if a carbon pile tester is used, those questionable batteries will fail the very same test that the handheld testers, passed.

I think if you're getting five years out of these batteries you're probably living in a warmer climate, you probably don't start the car multiple times a day and you're not using your automatic trunk feature all that much.

tbilisi79

I'm facing the same issue right now.
Yesterday the car didn't want to start. Last week as well. I have to jump,it with my Lincoln.
Both cars get driven few times a month. I'll take it back to,autozone as their last battery lasted only 2 month. Let's see if this one is defective as well.
I even let the car idle for an hour once a week to keep juices flowing.

Doublebase

If the battery is only lasting two months I'd tend to think you have a parasitic draw on your battery, a lot of people have mentioned the door witches as a culprit. Perhaps that's the problem? Because the workload of this car - although strenuous - shouldn't cause a battery to fail every couple months.