The first thing I would do is have the battery checked, just because a battery charges up does not mean it's a good battery. If the battery is sound and holds a charge off the bike I would look look for something that is still drawing power when the bike is turned off. Usually this will be something that was added to the bike. I've seen it happen a lot with radio's that have two power wires, one that powers the radio when the key is on, but the other is a direct connection all the time for memory.
I put a new battery on it. I charged it first for 2 hours and when I put it on the bike, it cranked right up. But, after riding for about an hour, I came back to the house and shut it down just to see if it would crank up again and got nothing. Dashboard lights up and all but it did not have enough power to turn over. Very frustrating.
Definitely get a permanent voltmeter wired up. I have one built into my valance panel.
You'd be surprised, if you have running lights and a hot headlight, it won't charge the battery. Even mine will only put out 12.4v at idle, climbs to 14.6 on the highway.
The POS aux lights that came with the bike would drop the volts to 12.8 at speed, much less at idle.
Now here's what you need to do. See the three yellow wires coming off your stator? Get your voltmeter out, set it to AC. Pull the connector and check voltage across any three wires. It should read at least 17v at idle, ~60 when above 2500rpm.
Plug it back together. Check your battery voltage (DC setting) across the terminals at idle, and at 2500. Get back to us with the results, we'll go from there.