Currently using the iPhone Air and my Series 7 Apple Watch battery is getting tired. It is showing 68% battery capacity now and that it needs service. I'm not really interested in paying for a battery replacement so I ordered a refurbished Apple Watch Ultra 2. I do use the cellular feature of my current watch, so I'll transfer that over to the Ultra 2 when it arrives. I was thinking about keeping the old Series 7 (Apple says I could get $65 for it but I don't really shop at the Apple Store ever) to wear to bed since I really like tracking my sleep, and it should be a good bit smaller than the Ultra 2. Is it really as simple as putting it on and raising my wrist in order for the iPhone to detect that I'm wearing a different Apple Watch? That's what Apple says......