My sl500 went into the shop to fix the stuck-in-park problem and sat for 17 days. When I picked up the car it started fine. I drove home a few miles parked in the garage and now it won't start. It acts like a dead starter battery. Electrical seems to work fine, but no start. Removed the starter battery (uh-oh?) and put a charge reader it said 815. the starter battery says sep 12 on the top, I assume that is when it was installed. I have only owned this car for a few months. Can someone advise me on what to do? I don't want to tow it to a shop. Thanks!