this is the third case I've seen of this, seems to be a problem with our cars. My IROC's battery died sometime in the past three-four months I was away from school. I've never ran the thing since, went out to start it and found it was completely drained of it's juice. the same thing happened to my old RS when I let it sit over the summer, completely drained battery. My friend's 89 Formula responded similarly when he let it sit for a month at my school's parking garage. Has anyone ever experienced this? Why did our batteries just lose all their juice from sitting? it's frustrating cause $50 a piece for batteries can get pricey! any thing I should check for and disconnect that might be bleeding out the juice. if you're wondering, I've got a fixed antenna on the IROC and the motor for the mechanical antenna on the RS was disconnected after is stopped working, so that eliminates a probable cause. not sure about my friends 89 Formula. anyways, shed some light on this for me, it's frustrating

 

Most anything electronic could be draining the battery(I see alternators do this often, even though they do charge while running). Some drain is normal, the car does 'use' the battery while it sits. If you aren't going to drive it for a few weeks or months, unhook the battery. Oh, and if it does become drained, charge it for a few hours .

 

It's normal for any car to do that, that's why new cars when shipped have fuses and breakers pulled. The ECM, and radio memory place a small drain on the battery that eventually will discharge it. You can either disconnect the battery or just purchase a little wall type trickle charger(14 bucks@whitney). The 200-500ma trickle charge will power the memory and provide minescule charging keeping the battery fresh. My rock sits a lot, I charge it once a month for a couple of days and the battery is always fresh. Lead acid batteries should always be kept in a state of charge, otherwise it's useful life is cut by more than half. Also the longer it stays discharged the less likely it will be able to be recharged.