The 911 guys have also had back luck with Optimas. Now, many of those cars sit for the winter, and I don't know how many use battery maintainers, but it doesn't seem that Optimas like to be run down. There was also an opinion that Optima quality has gone downhill, starting 4-5 years ago, but that was just an opinion.....shared by a number of folks who had Optimas from the start. Ron Porter