I dunno if this is already known of but I share it anyway - I usually put special weapons or magics in a quickslot to save time and I had done this for melfs ring and the ring of invisibility. When I got better rings I unequiped them and stuck them in with the rest of my inventory but when I tried using the spells they allowed from my quickslots they sitll worked even though they werent equiped! pretty cool eh? I think it may be a bug but not 1 I'm complaining about

I never did it with rings, but I'll give er' a go tonight. But I've noted that with most "active" (must be invoked) magic items they don't need to be equipped to use and therefore I store them out of the way in my various bags of holdings...

HOWEVER, I've also noted that many items do NOT recharge if in a bag of holding. So some you MUST keep out.