What wentouch said. Also, you may want to get something like a battery tender. I got mine a couple weeks ago and plug it in every time I get home from a ride. I don't ride everyday, but the bike is always ready to start up when needed.
I would also suggest NOT bump starting it and instead just getting a charger. unless go and ride the bike for at least an hour the battery won't really get a good charge and you risk having the battery lose capacity and eventaully just not taking a charge.
bump and jump starting are methods of last resort to get you home. after that you really need to put it on a charger.
The same thing happen to me. I called Yamaha the same day and they told me to jump start it using my car battery ...........but don't turn the car on:thumbdown , just use the power already in the battery. It enough to start the bike. Then ride it for about an hour or two. I had no problems since then:wink