Bhavanga is not something that one experiences actively (i.e., they are not “thoughts”.)
– All citta (loosely called “thoughts”) arise in citta vithi. Each citta vithi has 17 citta, and millions of them can run through the mind in a second.
– Bavanga is the “state of the mind” in-between citta vithi. But the does not register ANYTHING while in bhavanga.
– In most bhavanga states, the mind does not “feel” anything. It is thus normally in a “neutral” bhavanga state. But right after a strong sensory event, the mind may retain that “mindset” for a while. For example, if X hears that his father just died, that “sad mindset” could be with X for many days.
– In contrast, there will be citta vithi flowing during meditation. You may be thinking about the “calm mindset” during meditation. But those are still citta vithi, with “good thoughts”. That is why they provide calmness.
You may want to read the following post:
“Bhava and Bhavaṅga – Simply Explained”
If you still have questions, please feel free to ask.