iPhone 7 Plus Battery Life

I got a used iPhone 7 Plus as a temporary phone that I bought off of a friend. I set it up partially, because I don’t have access to set it up from a backup or from iTunes.

Because of that, I had to set it up as new, and download essential apps, and download the latest iOS update to restore from an iCloud backup.

I’m also in a place with horrible WiFi and no cell reception. I have TMobile, and I’m in the middle of nowhere, so it takes “bad” and makes it even worse.

So, currently I have no cell reception, poor WiFi signal, apps attempting to download, and a software update downloading. Are these all going to be contributors to a bad battery life? The battery health is at 82% maximum battery life, and my friend’s phone is currently at 89% and it lasts a pretty long time. Once I get home to a strong WiFi connection and cellular signal should I see a slower drop in battery life?

It’s currently in low power mode, but went from 52% to 44% in about 30 minutes. I’m not SUPER worried because I paid very little, and it’s a temporary phone, but of course I’d at least like it to work for me.

I also plugged it in, and it kept repeatedly making the charging sound. Is this also contributing to the problem? If it’s a real serious problem, is it anything apple can fix?