Have a 99 Buick Riviera, 3.8L Supercharged, 8 Years on original battery, 2 on 2nd. 3rd six Months. Battery dead after sitting 2-3 days. Mechanics checked parasitic draw, within spec. Checked all fuses, alternator, battery etc etc. No cause. Security light stays on full time now when driving. Frustrating. No one can pinpopint the problem.
Battery Dies on 1999 Buick Riviera
what kind of batteries are you using?? if they are cheap ones, then this is the result. make sure the cca are correct and make sure the cables are extremely clean.