Open Settings → Battery and look for Battery Health or Battery Health & Charging. Check maximum capacity, any service message and how long the phone lasts in the work you actually do. A capacity reading is most useful when you consider it alongside the pattern of battery use.
Find the readings for your iPhone
Start in Settings and open Battery. The name of the health panel and the information shown depend on the model and software version. Look for maximum capacity and any message about service or performance. Newer models can show additional information, including cycle count, in the battery settings. If a label in a guide does not match the one on your phone, search Settings for Battery Health and check Apple’s model-specific guidance before assuming the feature is missing.
Write down the phone model, iOS version and date with the reading if you intend to compare it later. If the phone has been repaired, check its service history where supported. A message about an unverified battery or an unavailable reading calls for a different check from a normal gradual decline. For an existing repair, ask the provider to identify the part and explain the message. Do not try to infer its condition solely from a percentage that the phone says it cannot verify.
Understand maximum capacity and cycle count
Maximum capacity estimates how much charge the battery can hold relative to when it was new. The percentage at the top of the screen represents the current level of charge. A phone can show a full charge and still hold less energy than it did when it was new. The health estimate describes the size of the available reserve, while the charge indicator describes how much of that reserve remains right now.
A cycle represents cumulative use equal to one full battery capacity. You can complete one over multiple days or charges. It does not count every time you plug in. Apple’s battery service guidance describes design targets and notes that real results depend on use and charging. Compare the guidance for your model rather than applying a single cycle count to every iPhone. A capacity estimate is also different from a warranty decision. Confirm service terms with Apple or an authorized provider for your location and device.
Look at what consumed the charge
In Settings → Battery, look at the available activity and app usage information. Match a period of rapid discharge to what the phone was doing. Navigation with the screen on, uploading video, and working in an area with poor reception can make a day look very different from one spent mostly on Wi-Fi. Compare days with similar conditions. If a certain app appears near the top, check how long you actively used it and whether it did work in the background.
Try a short test that reflects your own complaint. If the phone drops quickly overnight, record charge before bed and after waking, and check for activities in that period. If it struggles during commuting, repeat the same trip and compare signal conditions and screen time. Avoid drawing a conclusion from one day immediately after setting up a phone or restoring data, when downloads and other background work may be atypical. Our Android battery troubleshooting guide explains the same general method of comparing similar periods, although the menus differ.
Distinguish a charge limit from battery wear
Review the charging options available on your model. An enabled charge limit or an optimized charging feature can deliberately delay or limit charging in certain situations. Check the setting and the status message before deciding that the battery is unable to reach full charge. A health percentage and a charging limit can show similar numbers for unrelated reasons. Write down both if you are seeking help.
If charging pauses unexpectedly, look for any alert about temperature or accessories. Try an appropriate charger and cable that you know work, and test under ordinary indoor conditions. For a USB-C iPhone, our USB-C cable guide explains why appearance alone tells you little about a cable’s capabilities. A problem with just one accessory should be diagnosed separately from short runtime on a battery that did charge normally.
Decide whether service would solve your problem
Consider service when the phone consistently fails to last through your normal day or when the settings recommend service. An older phone used mainly at home may be usable for your needs even after some wear. A phone used for long shifts, navigation or emergency contact may need more runtime. Describe the problem in terms of real behavior when asking for help. Unexpected shutdowns, charging interruptions, and low capacity can require different checks.
Use Apple’s or the authorized service provider’s instructions before sending the device in. Make sure you can reach your important photos, files and account recovery information from another device. Our backup verification guide gives examples of checking recovery instead of relying on a success message. If the phone shows signs of physical damage or a swollen battery, follow Apple’s service and safety guidance and arrange professional help. Avoid pressing a lifted screen back into place or opening the phone yourself.
Track the change over time
Record maximum capacity occasionally under normal use and keep a brief note of the circumstances when a problem happens. A reading that changes by a small amount does not tell you how much practical runtime you lost on one specific day. Compare the trend with repeatable observations. If the phone begins to lose charge at a similar rate across several normal days, that pattern is more useful for service than an isolated screenshot.
If your daily routine changes, update the test. A new watch, travel schedule, or app can add background work or change network use. Start with the settings and activities you can observe. Change one thing at a time and check whether the phone lasts longer without losing a feature you need. This gives you a record of what helped and a clearer description of the remaining problem if you seek service.
If you are evaluating a used iPhone, ask to see the battery information on the device itself and check that the seller can demonstrate ordinary charging. A short inspection cannot establish how long it will last through your whole day. Factor potential service into the price if battery life is important to you, and confirm the model’s repair options before buying. Give any displayed service message more weight than a seller’s estimate of the number of hours the phone should last.
Frequently asked questions
Does a reading below 100 percent mean the battery is faulty?
Capacity normally changes with age and use. Compare the number with runtime, service messages and the guidance for your model.
Does plugging in count as one cycle?
A cycle is based on cumulative battery use equivalent to one full capacity. Several partial uses can add up to a cycle.
Can I compare two iPhones by maximum capacity alone?
Compare each phone with its own design and your workload. Screen time, apps and network conditions can change practical runtime.
