iPhone battery not charging to 100%? Here's the fix!

Trying to get your iPhone battery to 100%? Here's how!
(Image credit: Christine Romero-Chan / iMore)

I noticed something strange on my iPhone during a Southern California heat wave last summer: the battery would not charge past 80%. In fact, I remember noticing that it would sit at 80% for what seemed like an hour, with little change in that time — sometimes it would get to 83%, but nothing beyond that point. Even rebooting my iPhone didn't fix the issue.

If you have experienced your best iPhone battery not charging to 100%, here are some things to try and alleviate the issue. 

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Why is my iPhone not charging past the 80% threshold?

Fixing battery issues on iPhone

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If your iPhone is not charging to 100%, you may notice that it remains at the 80% threshold or something close to that (like 83-84% for me). That's because Apple introduced a new feature in iOS 13 called "Optimized Battery Charging." This feature has the software preventing or delaying your device's charging at 80% for as long as you aren't using the device.

With Optimized Battery Charging, the device uses machine learning to study your daily usage patterns and charging routine, so it limits charging at 80% until you need to use it. Believe it or not, always having your phone at 100% actually wears out the battery quicker — the optimal levels are between 30-80%, as these levels get the most out of your battery, especially Lithium-Ion, which is what's inside your Apple devices like your iPhone 14 or iPhone 14 Pro.

So while it may be an annoying feature, Optimized Battery Charging is supposed to help you out in the long run. It prolongs the iPhone and iPad's battery life and helps prevent you from wearing out the battery too quickly.

You may find your iPhone battery not charging to 100% because of the battery temperature. When you overcharge your iPhone or iPad, it may generate a lot of heat, which is detrimental to battery health. The heat that your device generates while charging basically exerts extra stress on the battery, reducing its lifespan. Again, Optimized Battery Charging and iOS can limit charging beyond 80% if the battery temperature exceeds Apple's recommended limits.

How to turn off Optimized Battery Charging

While the Optimized Battery Charging feature is supposed to help you extend your battery's life, maybe you want to turn it off to see if your device can fully charge to 100%. Or perhaps you don't like the feature. Thankfully, turning it off is easy!

  1. Launch Settings on your iPhone or iPad.
  2. Scroll down and tap on Battery.
  3. Tap Battery Health.

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  1. Tap the toggle for Optimized Battery Charging to OFF.
  2. You'll get two options for when turning Optimized Battery Charging to off: Turn Off Until Tomorrow or Turn Off (permanently). Choose which one you prefer.

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To turn Optimized Battery Charging back on, repeat steps 1-4 above, except the toggle should be green instead of gray.

Change charging location to a cooler location

As mentioned earlier, the battery's temperature can affect it, so your iPhone or iPad may not be able to charge to 100% and is stuck at around the 80% threshold. To fix this, you should try moving your iPhone or iPad to a cooler location, which would be more conducive. Avoid things like direct sunlight, rooms with poor ventilation, other appliances, and electronics, or other devices that can generate heat, if you can. If the environment is still too hot, you should try cooling it off with fans or air conditioners before attempting to charge.

Remove your phone case to dissipate heat

Charging iPhone

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While cases are great for protecting your iPhone or iPad from drops and everyday wear and tear, they can also trap heat from your device while it's charging or being used, which again, could cause your iPhone to not charge to 100%. If you have done the previous steps of turning off Optimized Battery Charging and moved to a cooler location, try removing your case. This way, the heat generated from the device can dissipate into the air, cooling off the battery.

You could also keep an eye out for cases that are designed to help dissipate heat, such as the Razer Arctech line of cases. When I tried them out for review, I noticed that it helped keep my iPhone cooler, and it didn't overheat while using resource-intensive apps or during charging.

Try closing out apps that are draining battery

Closing battery-draining apps.

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If several resource-intensive apps are running in the background, it may cause your phone to get warm. It would help to force quit those apps that are using significant battery life to prevent further battery drain as well as reducing strain on the device, allowing the battery temperature to drop slightly.

Use OEM charging accessories

Otterbox Fast Charge Lightning Usb C Cable Lightning

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Sometimes the problem can be because you are using fake or unauthorized charging accessories that don't have the proper Made for iPhone (MFi) certification from Apple. If you've exhausted all other options we've mentioned, try getting one of the best replacement Lightning cables, preferably from Apple if you can.

There are also trusted third-party brands like Anker's PowerLine III Flow cable or OtterBox's Fast Charge Lightning Cable, among others. It's also best to purchase replacement accessories from reputable stores with genuine products and check customer reviews first if you are buying from places like Amazon.

Make that battery last

If you have had trouble with your iPhone battery not charging to 100%, like me, then hopefully, these tips have helped you troubleshoot the issue. But if they haven't, then you may need to take your iPhone or iPad into an Apple authorized repair center to have it looked at or even replaced. That may be a little harder than usual to do right now, but we have a guide on how to contact Apple Support for your iPhone, iPad, Mac, or Apple Watch if you need help.

Updated September 2022: These are still the best tips for troubleshooting an iPhone battery that won't charge past 80%.

Christine Chan

Christine Romero-Chan was formerly a Senior Editor for iMore. She has been writing about technology, specifically Apple, for over a decade at a variety of websites. She is currently part of the Digital Trends team, and has been using Apple’s smartphone since the original iPhone back in 2007. While her main speciality is the iPhone, she also covers Apple Watch, iPad, and Mac when needed.

When she isn’t writing about Apple, Christine can often be found at Disneyland in Anaheim, California, as she is a passholder and obsessed with all things Disney, especially Star Wars. Christine also enjoys coffee, food, photography, mechanical keyboards, and spending as much time with her new daughter as possible.

With contributions from