This has been happening to my 2002 XG350 since i purchased it new. The original went dead 18 months and had to replaced with an "upgraded" one at the dealer. This "upgrade" one lasted about another 18 months. Then I purchased a $110.00 Sears Diehard which died just short of 1 year. This Sears battery being replaced was under warranty and didn't cost me any $$, due to the 3 year warranty. The small electrical test they do on the system said all was well after the new battery was install. My question is, what could be causing such a drain on the batterys I've had over the years and has anyone experienced this problem themselves? Batteries in my past cars have lasted anywhere from 3-5 years....and I think I got 6 years out of one once. There are also NO battery lights showing on the dash. The battery light does go on at ignition lamp test, but goes out within a few seconds. Thanx for any replies or ideas contibuted so I can take care of this situation. Steve S.