Are you asking if it will zero out the hours? If so, I can't imagine this to be the case. Otherwise, people could rollback their hours by simply disconnecting their battery. I would imagine they are storing that information on non-volatile memory, which is not affected by a power loss.
It should not reset the stored information but it should reset the computer itself. If it were "locked up" or you were having an intermittent issue with it, then disconnecting the battery for at least a minute (sometimes longer) should cause it to reset and clear any intermittent errors.
Of course, this is just an educated guess.