Battery Dead problems of the 2008 Lexus LS460

The contact owns a 2008 Lexus Ls460. The contact stated that the vehicle would not start unless the vehicle was jump-started. The vehicle was taken to the dealership where the battery was replaced twice; however, the problem still occurred. The dealer performed a diagnostic test but could not find the cause for failure. The contact called the manufacturer but was told that no failure could be found. The failure mileage was approximately 5,700. Updated 11/22/10 the battery failed several times. Updated 11/12/10.