At 11 years old I felt it was probably time to invest in a new Battery. Although the old one showed no obvious signs in daily use of failing I had become aware that the Stop/Start rarely cut in. I had also done some 'unofficial' discharge tests on the old one such as turning headlights and heated window on and seeing how the voltage held up. The voltage seemed to head south pretty quickly hitting around 12 volts after just a minute or two and very quickly reaching the 11.8 region. It was OK like