OK so I'm cheap .... Wal-Mart Shumacher battery tender for $19 bucks keeps me chraged and even does my garden tractor automatically sensing that it is 6 volts.
"sometimes you're the windshield .... sometimes you're the bug"
2014 328i Mojave Metallic
2009 328i Black Sapphire Metallic
2007 328i Black Sapphire Metallic
2007 Honda S2000 Berlina Black
(Hey Jim... am I diversified?)