... I have been able to roll start it since as soon as the bike takes off even at idle its fine.
How old is your battery? Batt cable terminals clean, shiny and protected with dielectric goop? Don't over look the positive terminal at the starter. Disconnect the ground cable prior to getting involved under the starter cover. Sparks bad.
Using a VOM, check battery voltage at idle revs at the battery terminals, then rev engine to 3K+ and check for a charge coming to the battery. What'cha see?
Your GEN lamp appears to be doing its job. The little bulb is a vital part of the
exciter circuit within the charging system. The Airhead's alternator does not provide but a tiny charge until the engine revs get up a bit -about 3-4K is where you get a full bump from the alternator. So, putt putting around town at low revs will drain the battery. Couple days of this and it's flat.
Flat battery=BAD. Battery Tender Jr=GOOD.
So. It's the weekend. Get crackin' and give us a heads up on your test results.