is a production date that I can't seem to find, that anything before is supposed to be of better quality. Anything afterwards, is supposed to be of lesser quality. I heard it was due to the inner materials for the core are not as good as they once were.
I had one on the old Z and it ran like a champ. Bought a new red top around a year or so and it crapped out around 6 months later. Turned it in and got another one. Talked to the auto store district manager who is a buddy I grew up with and says that was the story. He also said they've had about 3 times as much returns for them. This was last year around this time when he told me this. Don't know if they've changed anything about the battery production though since then.
