probably more like 4 really.16 hours of continuous use is going to be hard to find. All of the wireless models that are just earbuds and a connecting wire have very small batteries. Your best bet if you really need that much play time is to get 2 sets of semi-decent earbuds.
another reason why i'd never buy wireless earbuds (the other being i hate earbuds)My Jaybird X2's lasted probably 9-10 hours when I first got them. I could go to the gym for 2 weeks (4x a week for about an hour or hour and fifteen minutes) but the battery has noticeably degraded in quality. They are probably 2 years old at this point though. But I probably get like 6-7 hours out of them now.
I also have the Apple Airpods and those have pretty damn good life, although they don't block out as much sound as the X2's do. They sound a lot better than I would have expected though.
More like another reason you'd never buy anything with a rechargeable battery in them.another reason why i'd never buy wireless earbuds (the other being i hate earbuds)