Introduction
If your phone no longer lasts the day the way it used to, the first question is simple: is the battery itself worn out, or is something else draining it? Checking battery health tells you how much charge the battery can still hold compared with when it was new — different from which apps used the most power today.
This guide shows where to find battery health on iPhone and Android, what the number means, and how to decide whether it points to a battery that needs service or a software problem a new battery would not fix.
Battery health is not the same as battery usage
Keep two ideas apart before you open any menu.
Battery health (maximum capacity) is a long-term measure. It compares the charge your battery can hold now with what it could hold when new. A reading of 88% means a full charge today stores roughly 88% of the energy it did on day one. It falls slowly over months and years as the battery chemically ages, and it does not go back up.
Battery usage is a short-term record: how much power each app and system feature used over the last day or so. One misbehaving app can make usage look terrible on a day when the battery itself is perfectly healthy.
The fixes are different. A worn battery is a hardware matter: no setting restores lost capacity. Heavy usage is usually a software matter — an app stuck in the background, a poor signal, or a feature left running. Check health first, then check usage.
If your main problem is that the battery runs down quickly during the day, start with our companion guide — Why Is My Phone Battery Draining So Fast? — which diagnoses drain app by app. This article covers the other half of the job: measuring the battery itself.
How to check battery health on iPhone
Apple has shown battery health in Settings for years, and newer iPhones show more detail than older ones. The menu name depends on your model.
iPhone 15 and later
- Open Settings.
- Tap Battery.
- Tap Battery Health.
You will see Maximum Capacity as a percentage, plus Cycle Count, Manufacture Date, and First Use (on iOS 17.4 or later). A charge cycle is completed when you have used battery power equal to 100% of capacity — not necessarily in one charge. Using 70% one day and 30% the next adds up to one cycle.
iPhone 14 and earlier
- Open Settings.
- Tap Battery.
- Tap Battery Health & Charging.
You will see Maximum Capacity and a note under Peak Performance Capability. These models do not show a cycle count in Settings.
What Apple’s design figures mean
Apple designs its batteries to retain up to 80% of their original capacity after a set number of complete charge cycles, under ideal conditions:
| iPhone generation | Designed to retain up to 80% capacity at |
|---|---|
| iPhone 14 and earlier | 500 complete charge cycles |
| iPhone 15 and later | 1,000 complete charge cycles |
These are design targets, not guarantees.
What the messages on the screen mean
Peak Performance Capability — normal means the battery can support normal peak performance. Performance management applied means the phone has limited performance to prevent an unexpected shutdown. A “Service” message next to Battery Health means the battery’s health has dropped substantially — consider a replacement through Apple or an authorized service provider.
Apple does not publish a single percentage at which every battery must be replaced. The 80% figure matters because it is the design target above, and because AppleCare+ covers a battery replacement at no extra charge once capacity falls below 80% of the original, for as long as the plan is active. Outside warranty or AppleCare+, treat 80% as a prompt to look at real-world behaviour rather than as a hard deadline.
How to check battery health on Android
Android is less uniform than iPhone. Whether your phone shows a health figure at all depends on the brand, the model, and the software version. Work through the options in this order: the built-in Settings page first, the maker’s own diagnostic tool second, and a third-party estimate only if neither exists.
Google Pixel: the built-in Battery health screen
Android 16 brought a native Battery health screen to Pixel phones. On a Pixel 8a or later, go to Settings > Battery > Battery health. You will see a status — Normal or Reduced — and, by tapping Battery capacity, an estimated capacity as a percentage of a new battery. Google is explicit that this is an estimate from the battery’s fuel gauge, not a direct sensor reading.
For the cycle count, go to Settings > About phone > Battery information, which also shows the manufacture date and date of first use.
Two limits apply. First, Google states that the Pixel 6a, Pixel 7, Pixel 7 Pro, Pixel 7a, Pixel 8, and Pixel 8 Pro do not show a battery health status — only the Pixel 8a and later models get the capacity figure. Second, if you do not see the option at all, update the phone first; the screen arrived with Android 16.
Google rates Pixel 8a and later batteries to retain up to 80% capacity for about 1,000 charge cycles, and older Pixel batteries (Pixel 3 through Pixel 8 Pro and Pixel Fold) for about 800 cycles. Google calls a battery Reduced below 80% and recommends replacement — but that is Google’s guidance for Pixel phones, not a universal rule.
Samsung Galaxy: Battery information and Samsung Members
Samsung has traditionally not put battery health front and centre the way Apple does, but newer models running recent versions of One UI show more detail.
Battery information in Settings. On some newer Samsung phones, such as the Galaxy S25 series running One UI 7 or later, go to Settings > Battery and look for Battery information. Where present, it shows battery health as a percentage, the cycle count, and the manufacture date. Availability depends on model, region, and firmware, and Samsung has not published a list of supported models.
Samsung Members diagnostic. The Samsung Members app, pre-installed on most Galaxy phones, includes a built-in diagnostic. Open the app, tap Support, select Phone diagnostics, then tap Battery status and run the test. The result is a condition rating — Normal, Weak, or Bad — rather than a percentage. You can also reach it through Settings > Device care > Diagnostics > Phone diagnostics.
Other Android phones
If your phone is from another maker, check Settings > Battery for anything labelled Battery health, Battery information, or Battery status — some makers, including Motorola and Xiaomi on recent software, have added similar pages, but the rollout is uneven. If no built-in option exists, a well-regarded app such as AccuBattery can estimate health from real charge sessions over several days; treat its figure as an estimate, and avoid apps promising an instant percentage after one charge. Dialer codes such as *#*#4636#*#* open a hidden testing menu on some phones, but they are undocumented and inconsistent — a last resort, not a first step.
How to interpret your result
A single percentage never tells the whole story. Read it together with the phone’s actual behaviour.
| What you see | What it usually means | What to do |
|---|---|---|
| 95–100% | Battery is close to new | Nothing to do; if the phone drains fast, look at usage, not health |
| 85–94% | Normal wear for a phone used a year or more | Keep using it; check again in a few months |
| 80–84% | Noticeably reduced capacity | Watch real-world runtime; plan for a replacement |
| Below 80%, or a Service / Reduced / Weak message | Substantial capacity loss | Consider a replacement, especially if runtime is poor |
| Percentage drops sharply, or the phone shuts down at 20–30% | Possible battery fault | Get the battery checked by the maker or an authorized repairer |
Three cautions matter more than the number. First, do not apply one maker’s threshold to every phone — Apple’s 80% figure and Google’s “Reduced below 80%” label are each maker’s own guidance. Second, a low number with good real-world runtime is not an emergency. Third, health figures are estimates: a one- or two-point change between checks is normal variation, so look at the trend over months.
Signs your battery needs service vs. signs of a software problem
| Points to the battery | Points to software or usage |
|---|---|
| Runtime has gradually shortened over many months | Drain started suddenly, after an app install or update |
| Percentage jumps (30% to 5% in minutes) or the phone shuts down with charge showing | One app dominates the battery usage screen |
| Unusual heat during light use or charging | Drain is fast in one place (poor signal) but normal elsewhere |
| Service, Reduced, Weak, or Bad message, or capacity well below 80% | Runtime varies day to day with no change in the health figure |
| Phone only works while plugged in | — |
If the back feels swollen or the screen is lifting at the edges, stop using the phone and have it checked promptly — do not charge a swollen battery. If the signs point to software, the fix is in usage, not hardware: our guide on why your phone battery drains so fast walks through finding the app or setting responsible. To slow further ageing, avoid heat and switch on your phone’s charge limit or optimized charging if it offers one.
FAQ
How often should I check battery health?
Once every few months is enough. The figure moves slowly; check sooner if runtime suddenly gets worse or the phone starts shutting down unexpectedly.
Is 85% battery health bad?
Not on its own. For a phone a year or two old, the mid-80s are ordinary wear. What matters is whether the phone still lasts your normal day and whether it shows any service warning.
Why does my Android phone not show a battery health percentage?
Most Android phones have no built-in health screen. On Pixel, only the Pixel 8a and later show a capacity figure; on Samsung, the Battery information page depends on model, region, and firmware. Use the maker’s diagnostic app or a reputable estimator app instead — and treat the result as an estimate.
Can a software update improve battery health?
No. An update can improve battery life — how long a charge lasts — by fixing a power-draining bug. It cannot restore capacity a battery has already lost.
Should I replace the battery or buy a new phone?
If the phone otherwise does what you need and only the battery is worn, a battery replacement is usually the cheaper option — price it through the maker or an authorized repairer first. If the phone is also struggling with updates, storage, or performance, a new phone may make more sense.
The bottom line
Battery health is a simple idea with an uneven reality: iPhones show it clearly, Pixels from the 8a onward show it well, newer Samsung phones show it sometimes, and many Android phones do not show it at all. Find the figure your phone offers, read it alongside cycle count and real-world runtime, and do not treat one maker’s 80% line as a universal deadline. When the number, the messages on screen, and the phone’s behaviour disagree, trust the behaviour — and if the drain looks like a software problem, work through the drain diagnosis in Why Is My Phone Battery Draining So Fast? before spending money on a repair.
