Go for the PB2S if you don’t want to go bat$#|+ crazy on a charger.
It’s a little bigger than the original PB2, but takes 21700s and as improved handling of powerbank functions (eg, gets rid of the Apple bug). And doubles as a powerbank as well as charger, of course.
Oh yeah, it will fit 26650s to charge, but you won’t be able to keep the lid on it, but it’s nice to know they will fit.