Battery/Charging issues

[DEVO!]

Well I am on mt SECOND battery in 3 months!
I ride my bike daily and every once in a while it would not have enough power in the battery to start my bike. I replaced the battery and it worked fine for about 2 weeks and yesterday I came home from work parked in the driveway shut down and 10 minutes later I came out  to go to Cafe Desmo and it would not start no power. I dont get it my ride every day is about 20 miles one way back and forth to work and during my commute it seems fine. It did seem to get progressively weaker but I have no clue on how to check it and see what the problem is. I called the dealer and there are no appointments until Oct1st and they said to check it  with a voltmeter, does any one know how to do this? and if I do find out I have a charging problem what parts do I need to be looking at to replace or fix. I am really getting frustrated and batteries aint cheap!

[Howie]

This will walk you through the diagnostic steps:

http://www.electrosport.com/technical-resources/library/diagnosis/fault-finding-guide.php