How long do I need to idle the bike to charge the battery when not riding it for a couple of weeks? I try to ride all year in Colorado but there are some weeks when it is just colder than I want to ride. This morning I wheeled the Canyon Dancer out of the garage door and let it idle for about 10 minutes then shut if off and rolled it back in the garage. Am I using more battery to start it than I am putting back in with the idling? I have a battery tender (Schumacher) but am using it on my classic car right now.
Exactly what Rocky said. Alternator putting out 14v at idle will indeed charge your 12.5v battery. My voltmeter shows battery a little over 12v and with engine running at an idle, alternator goes to over 14v.