Yikes. . If the battery light is coming on and off, thats one of two things.
Thing #1, regulator rectifier is possibly failing.
Thing #2, regulator rectifier isnt connected fully, loosly connected, or battery termninals are loose

My SS/CR's battery light came on and off like that, and then one day came on, stayed on, and left me stranded (luckily only 5 miles from home).

I'd check it out before taking it on any 500 mile rides...

EDIT

I've got some regulator testing info up here:
http://www.rebelpacket.net/mai....html