my first HP, a 15c, stays home, safe & sound, with it's original spine-bound manual. I think I've replaced the batteries three times in some thirty-five years.
also have a 32sII that I bought off a friend who'd gotten it as a gift for his gf who was starting some math/sci class … but "she didn't like it" (which I read as, "wth is RPN". her loss!)