My 28 was going from low beam to total darkness then the high beam would kick in 1-3 seconds later, made for fun times. The battery died over a couple days the other week and the lights seemed to get worse.
I haven't riden at night since replacing the battery to see if it has fixed the lights, but it starts easier, idles better and seems to feel a bit more lively.
Might be worth a look at the battery first.