English Translation
I’ve been here for hours.
Exactly — “Я бывал тут часами” does not mean “I have been here for hours” in the English present-perfect sense.
Here’s why:
“Я был тут часами”
One concrete past event.
Natural English: I was here for hours (on one occasion).
“Я бывал тут часами”
Iterative/habitual past.
Natural English: I used to be here for hours / I would spend hours here.
It means “this happened repeatedly in the past,” not “I have just been sitting here for hours (and I’m still here).”