Well I am a new rider, I am riding my brothers yamaha r1 2002, 12k miles. It has been sitting in the garage since 08 without running, Last week i pulled it out the garage and changed the oil, gas, and battery. It started up perfectly and ran.
The only problem was when it started the rpm idled at about 1300 then it started dropping as soon as the bike starting warming up, however it still ran perfectly and did not stall on the streets.

Now yesterday i was cruising and the bike randomly stalled out. This happened to me a couple times and i have no idea why, and now today i rode down the street came back everything good but the battery died. Which makes no sense because is a new battery. This is the first time the battery has died since i started riding about a week ago.

Anyone know what the problem could possibly be? And is it because of the battery that my idle rpm is under 1,000?

Thank you all.