I replaced the OEM Varta battery on my 2004 (Sep 2003 build) @23K miles. I guess over 10 and a half years of life isn't too bad even with the limited mileage. The funny thing is that even after such a good life, it had some juice left in it. I had played the radio for about an hour while washing cars the other day and then when I went to start her up, the engine wouldn't quite turn over. Waited an hour and she started right up. I figured it was time and traded it in on a new Autocraft.