Hi!
I use an Apple Watch 5 as my daily watch (except formal ocassions) and I really love it, but noticed that the battery health has dropped to 80% and barely lasts a whole day. I'm really impressed that it held on for so long as I bought it back in 2019 alongside with an iPhone 11 pro. Since then I got an iPhone 15 that I plan to use for at least 4 or 5 years, but I know that my Watch has 1 or 2 years of support (latest WatchOS) and my question is how many iOS versions can I update on my phone till I can not connect the 2 devices? So for the next five years if I update my phone will I be able to connect to my phone or there will be an update earlier that will not be compatible.
The reason is I don't know if I should replace the battery and use till I replace my phone or to buy a newer watch that is basically the same except for a little bigger screen and a full keyboard that may be useful once in a while.
For replacing the battery it costs 87 USD (converted) and getting a new watch is either 390 USD (SE 2022) or 590 USD (Series 9) and I don't know if it is worth the difference since there is nothing new that I would use, my only fear is that there will be a point where I can't use the 2 device connected and I will be there with a watch that does not do it's job for me and I'm uncertain if my next phone is going to be an iPhone so for 1 or 2 years I will not buy a new one. Thanks for your help in advance!
Theoretically, forever. Each watchOS version requires a minimum iOS version (e.g., watchOS 10 requires iOS 17 as a minimum), but it doesn't work that way in the reverse - iOS 17 should be able to pair with any watch going back to the original Apple Watch, as will iOS 18.
That said - people do occasionally have issues when pairing doesn't happen. But it is supposed to work that way. Currently I use an Ultra but I have my backup Series 5 still on watchOS 9 but it remains paired with my 13 Pro running iOS 17.1.1 (I had to unpair both watches when I did a factory reset and restore of my phone last month and re-paired both watches just fine).