This is 3rd battery in a year . 06 GT shaker 1000 . Any idea ?

 

Have you had the alternator load tested? The charging system in these S197's is mediocre at best. Usually, when one component goes, it takes out another.

The 05's and 06's are notorious for draining the battery if the Shaker system isn't turned off. The amp will continue to draw power and kill the battery.

 

The charging system in the 06 is less than ideal, I think I read that the stock system needs ~1 hour drive to fully recharge. Couple that with the Shaker head-end/amp shutoff known issues, and you are bound to have battery issues.

My 06 is a garage queen during the work week and I found my battery completely dead a few times when I had the Shaker 500 unit installed. I replaced the Shaker 500 with an aftermarket system and have not had a single battery issue since the swap. (and I always turned the Shaker off prior to shutting the car down per forum recommendations)