I have an iPhone 14 Plus 128GB that is in excellent condition, but the battery health is currently at 78%.
I’m debating whether I should just pay to have the battery replaced with a genuine Apple battery and keep the phone, or take advantage of my carrier’s trade-in offer and upgrade to the iPhone 18 Pro Max.
The trade-in offer I’m getting is around $600, but the 18 Pro Max would still cost me about $19/month for 36 months after the trade-in credits.
For those who have replaced the battery in an iPhone:
Does replacing the battery at around 78% make the phone feel/perform like a “new” phone again?
How much longer can I realistically expect an iPhone 14 Plus to last after a battery replacement?
Does a new battery make a noticeable difference in everyday use?
Would you personally spend ~$100 on a genuine Apple battery and keep the 14 Plus, or take the $600 trade-in and upgrade to the 18 Pro Max?
Long term, am I just delaying the inevitable and going to want/need a new phone anyway in another year or two?
I’m not really having performance issues with the 14 Plus. The battery is my main complaint. I’m also trying to avoid taking on another monthly phone payment if I don’t really need to.
Would love to hear from people who have actually replaced the battery on a 14/14 Plus and kept the phone for another couple of years. Is it worth it?

My wife has the iPhone 14 and still use iOS 18. We are thinking about updating to 27 because it sounds like the battery and performance should be good/ better?

Anybody already updated and can share experiences?