iphone randomly turning off with battery remaining

Hi there Jamiielee,

Welcome to the Apple Support Communities! It sounds like your iPhone 6 and your husband's iPhone 5s are shutting down when they hit 50% battery life, despite letting the devices drain completely and then charging them fully. I rely on my iPhone every day, so I know how important a reliable battery is. I'll be more than happy to help you get this resolved.

Let's take a look at the battery usage on both devices as a starting point. This link has some great tips for maximizing battery performance:

Batteries - Maximizing Performance

This section specifically will walk you through how to check battery usage and background activity:

View Battery Usage information

iOS 9 is designed to be the most battery-efficient iOS ever. And it gives you more precise ways to manage your device’s battery life, because you can see the proportion of your battery used by each app (unless the device is charging). To view your usage, go to Settings > Battery.

Here are the messages you may see listed below the apps you’ve been using:

Background Activity. This indicates that the battery was used by the app while it was in the background — that is, while you were using another app.

• To improve battery life, you can turn off the feature that allows apps to refresh in the background. Go to Settings > General > Background App Refresh and set the switch to Off.
• If the Mail app lists Background Activity, you can choose to fetch data manually or increase the fetch interval. Go to Settings > Mail, Contacts, Calendars > Fetch New Data.

Location and Background Location. This indicates that the app is using location services.

• You can optimize your battery life by turning off Location Services for the app. Turn off in Settings > Privacy > Location Services.
• In Location Services, you can see each app listed with its permission setting. Apps that recently used location services have an indicator next to the on/off switch.

Home & Lock Screen. This indicates that the Home screen or Lock screen was displayed on your device. For example, the display was awakened by pressing the Home button or by a notification.

If an app frequently wakes your display with notifications, you can turn off push notifications for the app in Settings > Notifications. Tap App and set Allow Notifications to Off.

No Cell Coverage and Low Signal. This indicates that either you are in a poor cell coverage area and your iOS device is searching for a better signal or that you’ve used your device in low-signal conditions, which has affected your battery life.

You can optimize your battery life by turning on Airplane mode. Swipe up to open Control Center and tap the Airplane mode icon. Note that you cannot make or receive calls while in Airplane mode.

You'll want to look at the section that's labeled "Last 7 Days" and also tap on the clock icon. From there, make note of any apps or processes that have been pulling a lot of battery or are running in the background. From there, you can go into Settings and adjust the refresh rate, etc. Test out your device to see if these changes prevent your phones from turning off at the 50% mark.

If you're still running into issues, we'll want to create a backup of your devices. Here's a resource on how to do that:

How to back up your iPhone, iPad, and iPod touch

After the backup is complete, you'll want to try resetting the settings on both iPhones. This will not impact any personal data (e.g. pictures, apps). You will need to adjust user-specific settings, like wallpaper and ringtones. Also, make sure that you have your preferred Wi-Fi network names and passwords available, as this step will delete those. Test both devices after the reset to see if the issue persists. To perform the reset, go to Settings > General > Reset > Reset All Settings.

Finally, we would want to restore both devices to factory settings temporarily. This step allows us to isolate whether there is a hardware or software issue present by installing a fresh copy of iOS. Once the device is restored as new, you'll want to see if there are still issues with battery performance. If everything checks out, you can restore your backup. These articles have information on completing both steps:

Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings

Restore your iPhone, iPad, or iPod touch from a backup

Have a fantastic day!

This does not address the question, does it?

Phone should not turn off at 50% battery life

For the past 2 nights at around 1:30 to 2:00 am my phone shut off with 50% to 60% battery remaining. when it shut off the first time i was at work and couldn't do anything it stayed off 3 hours then turned itself on to let me know it now needs to be charged. tonight it did it again only this time i was home and could google it to see if there was anything i could do, it taught me how to force start my phone. I have tried the reset with itunes and it still happened tonight. I am running IOS 10.3.3 is there anyone who can help me with this?

Hi to all. I have iPhone 6s and have exatly same problem. My phone turn of even battery remaning on 40-50% sometimes in 60%. It's not normal even all function turn on ( lovation service, automaticly mail push and everthing else). I try factory reset, I try full discharege and fully charge phone but problem still the same.

@Alex _oz I think that you van agree with me that even all background process are ON the phone don't going to OFF with 50% battery remaning. It's not normal. In that case phone can be faster discharge but not turn off.

I think that is some hardware problem and phone must be replaced...