I've had my RX-8 since November '04. Recently, over last few months, if I leave my car sit for 3 days or so the battery dies. I took it to the dealer (Maple Shade Mazda) for the third time this week and for the third time they replaced the battery. The service guy told me the since I don't drive that often that I should have a trickle charger on it. I pretty much told him that he was out of his G-- Damn mind and that the next time this happens I'm getting a new car under NJ's lemon law. Has anyone else had this problem? I check for a bad ground and to see if the regulator was over charging the battery. Any suggestion?

 

Your service guy is an idiot. Leaving a car sit for three days should never drain a battery. 6 months, maybe... But three days? Get outta here!

The dealer need to properly diagnose the problem. It seems that you have some kind of electrical device that's draining your battery. Aftermarket stereos and alarm systems are notorious offenders.

This is not rocket surgery. Talk to the general manager at the dealership and tell them that you insist on a proper diagnosis.

If the problem is credibly determined to be an aftermarket device, be prepared to pay the bill, even if the car is still under warranty... Although, if that happens, I would personally lobby for a free repair after all you've been through.

 

There would be a dozen threads covering this. Most people find that their trunk has accidentally been left open, and the battery is drained by the illuminated trunk light. One at least one occasion, a faulty Nav unit between the rear seats drained the battery.

Whatever the reason, it's not normal for a battery to be drained because the car hasn't been moved in three days. That service manager has rocks in his head if he's changed three batteries in a week.

 

This thread doesn't belong in General Automotive, BTW.

 

Im sure the service guy checked this (I hope), but if your battery ports are corroded/dirty the battery will not charge correctly while the car is running. I had this problem about a week ago in my lexus.