This doesn't involve the quantified self component but: CoconutBattery Online (http://online.coconut-flavour.com/ http://online.coconut-flavour.com/) has massi

This doesn't involve the quantified self component but: CoconutBattery Online (http://online.coconut-flavour.com/ http://online.coconut-flavour.com/) has massively aggregated Coconut Battery data ("over 150,000" data points) from the last five or eight years of Apple laptop models. It helps give a sense of laptop cohort's battery longevity.