I just ordered a Note 4 and a Otterbox case, cause, hey, I'm paranoid. Just wondering if I get a wireless charging back, I imagine it won't work through a Otterbox?
I wireless charge my Note 5 through a fairly thick Seidio case. Some chargers have a hard time with the thickness of it though, others are just fine. Your results may vary.
That said, My girlfriend has a note 4 with a charging back on it, and it's hit or miss if it'll charge even with just a thin bumper/back style case.