A bad voltage regulator (VR) will cause the same symptoms you have. On a SEUC (no help to you), it's easy to see: the voltage gauge will show about 14 volts when the system is running properly, but will only show battery voltage (about 11 with the cheap gauges HD buys) if the stator isn't making electricity or the VR is burnt out.
When the charging system goes bad, the battery can keep the bike running for a fairly long time, often long enough to get you home, but b/c it's been drained down, it doesn't have enough juice to run the starter--and each time you hit the start button, it discharges what little is left in the battery. Sometimes the battery will be fine after getting a fill-up from a full-power charger (not a battery tender), but if it's been drained too far and left for too long, not.
So, the problem could be any one of the three (stator, VR, battery), or any two of them, or all three. I'd start troubleshooting by fully charging the battery, then try starting the bike 3 or 4 times in a row. If it works, the battery is probably OK (and check the cables for corrosion), so you'll need to check the VR and/or stator.