How To Use Apple’s iPhone Battery Health Tool


How To Use Apple's iPhone Battery Health ToolPin

There’s a cool iPhone battery health tool built into iOS. Here’s what it does and how to use it!


Apple took a lot of flak some years ago when it was revealed that the company designed iOS to purposely slow down the performance of iPhones as their batteries aged. This had many pundits in the press screaming bloody murder – although they shouldn’t have been.

Apple was simply dealing with the physics and chemistry of batteries. As they age, they lose their ability to keep their capacities filled to a maximum. Since faster computer processes consume more battery power, Apple decided to design iOS to maximize battery life over speed.

It was the right move, as a faster phone that only lasts four hours is a lot less beneficial to the user than a slightly slower phone that continues to last all day. Regardless, Apple probably should have made users more aware they were doing this. That’s why shortly after the uproar, Apple unveiled a new battery health tool in iOS 11.3 designed to do just that.

How To Use Apple's iPhone Battery Health ToolPin

iPhone Battery Health: How iOS’s Battery Health Tool Works

You’ll find the battery health tool in the Settings app. Here’s how to find it:

  1. Open the Settings app.
  2. Tap Battery.
  3. Tap Battery Health & Charging.

At the top of this page, you’ll see an explainer about how smartphone batteries work in general. Tapping the link takes you to Apple’s iPhone Battery and Performance page, where Apple explains:

“While performance impacts are reduced as much as possible, battery aging might still eventually lead to noticeable, possibly temporary, effects. Depending on the battery state and the tasks that your iPhone is handling, examples might include longer app launch times, lower frame rates, reduced wireless-data throughput, backlight dimming, or lower speaker volume.”

Apple

Below the explainer, you’ll find a field labeled “Maximum Capacity” followed by a numerical percentage. If this reads 100% your battery has the exact same full capacity it had when you first bought the iPhone (if it was brand new).

Below the field labeled Maximum Capacity if you see a field labeled “Peak Performance Capacity” it means your battery is in tip-top shape even if its maximum capacity isn’t 100% anymore.

iPhone Battery Health: Optimized Battery Charging

Your iPhone can also learn when you use it and thus need the most battery capacity. Apple calls this “optimized battery charging” and is works by the iPhone learning your usage patterns and thus waiting to charge your iPhone battery to maximum charge until it knows you’ll need it. As Apple states:

“Built-in dynamic software and hardware systems will help counter performance impacts that may be noticed as your iPhone battery chemically ages.”

Apple

Most people will want to keep optimized battery charging turned on. Here’s how to do that:

  1. Open the Settings app.
  2. Tap Battery.
  3. Tap Battery Health & Charging.
  4. Next to “Optimize Battery Charging” toggle the switch to ON (green).

iPhone Battery Health: Clean Energy Charging

Apple also has another battery feature called Clean Energy Charging. This feature intelligently tries to reduce your carbon footprint by waiting to charge your iPhone until lower carbon emission electricity is available. It’s a very cool feature and one that is great for the environment. Here’s how to use it:

  1. Open the Settings app.
  2. Tap Battery.
  3. Tap Battery Health & Charging.
  4. Next to “Clean Energy Charging” toggle the switch to ON (green).

iPhone Battery Health: See Which Apps Are Hogging Your Battery Life

One final cool iPhone battery health feature is the ability to see which apps are hogging your iPhone battery life. Here’s how to use it:

  1. Open the Settings app.
  2. Tap Battery.
  3. Scroll down until you see the “Battery Usage By App” header.

Under the “Battery Usage By App” header, you’ll see a list of the apps on your iPhone that hog most of your battery, from biggest hogs to least-biggest. If you don’t like how much battery life the app is hogging, now you know which apps to use less – or delete from your iPhone completely.

Latest Smartphone Releases


  • Xiaomi 15S Pro

    The Xiaomi 15S Pro didn’t come with a flashy launch, but it brings some seriously heavy hardware to the table. A custom 10-core chip, Leica-engineered cameras, and one of the brightest displays on the market

  • Samsung Galaxy S25 Edge

    At just 5.8mm thick, it’s one of the thinnest Android phones ever made—but don’t let the slim profile fool you. This phone is all flagship under the hood.

  • Nothing Phone (3a) Pro

    It’s got the same slick design and OLED display, but adds a periscope zoom camera and a 50MP front-facing shooter.

  • Nothing Phone (3a)

    The Nothing Phone (3a) nails the formula: give people what they actually want, keep the price low, and make it look cooler than anything else in its class.

  • Motorola EDGE 60 Pro

    With a bold design, flagship-like display, and surprisingly refined camera system, it’s one of the most interesting mid-range phones of 2025.

  • Google Pixel 9

    I’ve been using the Pixel 9 for a few weeks now, and honestly? It nails all the basics—and a bit more. Killer stuff all round!

  • Google Pixel 9 Pro

    I’ve used the Pixel 9 Pro as my daily device, and it’s hands-down the best balance of power, practicality, and photography you’ll find on Android right now.

  • OnePlus 13

    I’ve been using the OnePlus 13 as my daily driver for a few months now—and I’ve got to say, it’s easily one of the best Android phones I’ve tested this year.

  • Xiaomi 15 Ultra

    After using the Xiaomi 15 Ultra for over a week, I can confidently say: this phone is an absolute beast. It’s made for camera nerds, power users, and creators.

  • iPhone 16 Pro Max

    If you’ve been holding out for a truly complete iPhone, the 16 Pro Max delivers—hard. After using it daily, I won't be going back…

  • Google Pixel 9 Pro XL

    Big screen, big battery, and even bigger brains—this is the Pixel to get if you want Google’s best hardware and longest support.

  • Google Pixel 9a

    The Pixel 9a brings Google’s flagship-level smarts to a budget-friendly package, and it’s easily one of the best-value Android phones of 2025.

Best SIM-Only Plans & Deals


  • iD Mobile 1 Month SIM-Only: 108GB

    Another high-data, low-cost option with no contract. 108GB for just £9, full 5G access, and the same goodies you get with 12-month deals.

    +

    Data: 108GB

  • iD Mobile 1 Month SIM-Only: 20GB

    The lowest price option. 20GB for £6 with all the same perks as pricier plans. Great if you don’t use much data and want to save every penny.

    +

    Data: 20GB

  • iD Mobile 1 Month SIM-Only: 110GB

    This plan gives you big data and zero commitment. 110GB for just £10 with all perks intact. If you need more data but want the freedom to cancel, this is the one.

    +

    Data: 110GB

  • iD Mobile 1 Month SIM-Only: 60GB

    More data, same price. For just £8/month, you get 60GB on a no-strings 1-month rolling plan. Ideal for users who stream often but don’t want long commitments.

    +

    Data: 60GB

  • iD Mobile 1 Month SIM-Only: 40GB

    Perfect if you want full flexibility. You get 40GB and all of iD Mobile's perks with no lock-in, annual increases, or setup fees. Great for short-term users.

    +

    Data: 40GB

  • iD Mobile 12 Month SIM-Only: 60GB

    One of the best pound-per-GB plans around. You get 60GB for £8 with £25 cashback, which means you’re effectively paying closer to £6/month. Includes roaming and data rollover.

    +

    Data: 60GB

  • iD Mobile 12 Month SIM-Only: 108GB

    This deal gets you a healthy 108GB of 5G data for less than a tenner, with no upfront costs and £24 cashback. All the perks are included too: data rollover, roaming, and loyalty rewards.

    +

    Data: 108GB

  • iD Mobile 12 Month SIM-Only: Unlimited Data

    This iD Mobile plan doesn’t just compete on price, it’s up there with the best of them. Unlimited everything, a year-long lock-in with no price rises, and £42 cashback straight to your pocket. It’s like getting nearly 3 months free.

    +

    Data: Unlimited, No Speed Caps

  • Mint Mobile 20GB Plan

    If you're looking to save some cash on your bills, this plan is an awesome option. You'll get 20GB of data per month and 20GB hotspot data allowance. For moderate to heavy users, that should be more than enough. I seldom use more than 10GB of data a month, and I'm always using my phone

    +

    Data: 20GB

  • Mint Mobile 15GB Plan

    If you don't use a lot of data, this plan is a great option. You'll get 15GB of data per month and 5GB hotspot data allowance. It's not a lot but for light users, it is likely more than you'll ever need

    +

    Data: 15GB

  • Visible+ Pro Plan

    Visible+ Pro is built for heavy users who want it all: 4K streaming, ultra-fast hotspot speeds, and premium 5G access on Verizon’s best network. No throttling. No compromises. Just pure, high-performance mobile.

    +

    Data: Unlimited

  • Visible+ Plan

    If you’re tired of overpaying for unlimited data, Visible is one of the best alternatives out there—especially right now. For a limited time, you can get Visible’s unlimited plan for just $20/month, and that price is locked in for an entire year when you use code SAVE5 at checkout.

    +

    Data: Unlimited