After more than 15 years covering everything Apple, it’s with a heavy heart we announce that we will no longer be publishing new content on iMore and the iMore forums will be closing as of November 1st, 2024.
If you're using your new phone more, that will be a factor. Go to Settings > General > Battery and scroll down to see which of your apps are battery hogs.
Welcome to iMore! In addition, make sure you're running the latest version of iOS. Earlier iOS 9 releases had a lot of reports of battery issues. Did you set your iPhone up from an iCloud/iTunes backup or set it up as a new device? Setting up as new generally sees improved battery performance. It takes a lot of time but I think it's worth the extra effort.