I replaced the battery on my 94 Deville about 6 months ago. I haven't had any issues unless the car sits for about 2 weeks without being started. If that happens, the battery is dead. A couple of days ago I got in the car after driving it for about an hour, and the battery was dead. I was able to jump it with a jump box. Once it is started, everything seems fine. I have good lights and everything so the charging system appears to be working. I can't figure out why the battery is not charging. I took it home and put it on a slow charge for a few hours until the battery showed a full charge. The car started right up just it should. A few hours later and it was dead again!