Quick answer
On iPhone, open Settings › Battery › Battery Health (called Battery Health & Charging on some versions) and read the Maximum Capacity percentage. On a Mac, open System Settings › Battery and click the info button next to Battery Health. iPads have no built-in battery health screen, so use a Mac utility or ask Apple Support.
What battery health actually measures
Battery health is the share of its original capacity your battery can still hold. iPhones, iPads and Macs all use lithium-ion batteries, and every lithium-ion battery loses capacity as it ages and works through charge cycles.
One charge cycle is a full 0 to 100 percent's worth of charging, even if it is spread over several top-ups. The loss is gradual: there is no fixed number of cycles after which the battery stops working. It simply holds a little less each month.
A Maximum Capacity of 90 percent means the battery holds 90 percent of the charge it held when new. That is why an older phone running exactly the same apps can be empty by mid-afternoon when it once lasted until bedtime. Apple considers a battery healthy above 80 percent and recommends a replacement once it drops below that.
How to check battery health on iPhone
Your iPhone shows battery health directly in Settings, with no app needed.
- Open the Settings app.
- Tap Battery.
- Tap Battery Health. On some iOS versions this is labelled Battery Health & Charging.
- Read the Maximum Capacity percentage.
The screen shows more than one number, and each one tells you something different.
- Maximum Capacity is the headline figure. A new iPhone sits at or very close to 100 percent, and it falls slowly with use.
- Peak Performance Capability tells you whether the battery can still supply full power when the processor needs it. If the battery has worn badly, you may see a message that performance management has been applied. That means the phone is limiting peak performance to avoid unexpected shutdowns.
- Optimized Battery Charging learns your routine and holds the charge at 80 percent overnight, finishing the charge shortly before you usually unplug. Sitting at 100 percent for hours stresses the battery, so leave this on.
The Battery Health screen arrived with iOS 11.3 and covers iPhone 6 and later. Every iPhone that can run iOS 27 has it.
What the battery health numbers mean
The Maximum Capacity figure tells you how much wear the battery has, and what you should expect from it day to day.
| Maximum Capacity | What it means | What to do |
|---|---|---|
| 95–100% | Effectively new. Typical for a phone under a year old. | Nothing. |
| 85–95% | Normal wear, usually after one to two years. Slightly shorter battery life. | Keep good charging habits. |
| 80–85% | Tired. A heavy day may need a top-up. | Start planning a replacement. |
| Below 80% | Degraded by Apple's definition. Possible performance management and sudden shutdowns. | Replace the battery or the device. |
If your iPhone shuts off at 20 or 30 percent with no low-battery warning, check this screen first. A degraded battery can report charge it cannot actually deliver under load, and a replacement normally ends the problem.
How to check battery health on iPad
iPads do not show the iPhone's Battery Health screen, even though they use the same type of battery and wear in the same way. You have three options.
Use a Mac utility
coconutBattery is a Mac app that can read battery data from a connected iPhone or iPad, including current capacity and cycle count. Connect the iPad to your Mac with a cable, trust the computer if asked, and open the app.
Use a third-party iPad app
Some App Store apps claim to show battery data on the iPad itself. Their accuracy varies and many carry heavy advertising, so read recent reviews before installing one and treat the figures as a rough guide.
Ask Apple
Apple Support and Apple Stores can run a diagnostic that reads the iPad's battery health accurately. This is the most reliable route if you are deciding whether to pay for a replacement. Connecting the iPad to Finder or the Apple Devices app shows only basic device information, not a capacity figure.
iPad batteries are much larger than iPhone batteries, so an iPad at 85 percent health often feels no different in daily use. The wear shows up later than it does on a phone.
How to check battery health on Mac
MacBooks report battery health in System Settings, and they give a detailed breakdown in System Information.
- Open the Apple menu and choose System Settings.
- Click Battery in the sidebar.
- Find Battery Health and click the info (i) button next to it.
- Read the status: Normal means the battery is fine, Service Recommended means it has degraded enough that Apple suggests a check.
On older versions of macOS, hold Option and click the battery icon in the menu bar. The menu shows the battery condition, with the same Normal or Service Recommended wording.
How to see cycle count and capacity on Mac
- Open the Apple menu and choose About This Mac.
- Click More Info, then System Report (on older macOS versions, click System Report directly).
- Select Power in the sidebar.
- Read Cycle Count, Condition and Maximum Capacity.
Apple says most modern MacBook batteries are designed to keep 80 percent of their original capacity after 1,000 cycles. A Mac at 500 cycles and 90 percent is doing well. One at 300 cycles and 82 percent is wearing faster than it should, and is worth a service check. Older models may have a lower cycle rating, so look up your specific model on Apple's support site.
If the Mac reports Normal but battery or charging behaviour seems wrong, resetting the power controller can help on Intel models. Our guide to resetting the SMC and NVRAM on a Mac covers which Macs need it and how.
How to make your battery last longer
You cannot stop a lithium-ion battery from ageing, but these habits slow the wear.
- Avoid heat and severe cold. Direct summer sun and a freezing car overnight are both hard on the battery. Keep devices at moderate temperatures where you can.
- Do not run it to zero. Full discharges were good advice for older battery types, not for lithium-ion. Keeping the charge roughly between 20 and 80 percent most of the time is gentler.
- Leave Optimized Battery Charging on. It cuts the hours your device spends sitting at 100 percent.
- Use a decent charger. It does not have to be Apple's, but avoid cheap unbranded chargers that can deliver unstable power.
- Store devices at about 50 percent. For long-term storage Apple recommends a half charge with the device switched off. Check every few months and top it up if needed.
- Keep software up to date. Apple sometimes ships power-management fixes in updates.
Daily battery life also depends on settings, not only on battery wear. Our 10 tips to improve battery life on iOS 27 beta cover background activity, display and location settings, and most of them apply to the public release too. If the phone is slow to charge or will not charge at all, work through the iPhone charging fix guide before blaming the battery.
Battery health and the iOS 27 beta
Installing a beta does not change your battery's Maximum Capacity. A beta can drain the battery faster for the first few days while the system re-indexes photos and files, and early builds sometimes include power bugs. That is a software problem, and it is separate from battery wear.
If you are testing iOS 27.2 beta 4 (24B5110a) and drain continues for more than a few days, check the per-app breakdown in Settings › Battery, then look for your symptom on our iOS 27 known bugs page. Report anything new through Feedback Assistant so Apple sees it.
When to replace your battery
Replace the battery when it is below 80 percent and you notice real problems: much shorter battery life, sudden shutdowns or slowdowns from performance management. At that point the cost is usually worth it.
Between 80 and 85 percent it is a judgement call. If you plan to replace the phone within six months, carrying a charger may be fine. If you want another two years from it, a new battery makes sense.
Apple charges different amounts depending on the model, and MacBook replacements cost more than iPhone ones because the battery is harder to reach. Check the current price for your device on Apple Support before you book. Third-party repairs can be cheaper, but a poor fit or a non-genuine battery can perform badly or create a safety risk, so use a well-reviewed shop if you go that way.
On a phone that is already several years old, weigh the battery against the device. A new battery restores battery life but does not make the phone faster or add features. If your model is close to the end of updates, read what happens when Apple stops supporting an iPhone before you spend money on it.
What to do next
Check Maximum Capacity every few months; it takes seconds. If yours is above 80 percent, focus on settings and habits, starting with the iOS 27 battery life tips. If it is below 80 percent, book a battery replacement before the shutdowns start.
Frequently asked questions
What is a good battery health percentage on iPhone?
Anything from 95 to 100 percent is effectively new. Between 85 and 95 percent is normal wear for a phone that is one to two years old. From 80 to 85 percent you will notice shorter battery life. Apple treats a battery below 80 percent of its original capacity as degraded and recommends a replacement at that point.
Why does my iPhone shut down at 20 or 30 percent?
A worn battery can no longer deliver peak power on demand, so the phone may switch off even though the indicator still shows charge left. Check Settings › Battery › Battery Health. If Maximum Capacity is low or you see a message that performance management has been applied, the battery is the likely cause and a replacement usually fixes it.
Can I see battery health on an iPad?
Not in the same way as on iPhone. iPads have not offered the iPhone's Battery Health screen with a Maximum Capacity figure. You can read capacity and cycle count with a Mac utility such as coconutBattery while the iPad is connected, use a third-party app with care, or ask Apple Support or an Apple Store to run a diagnostic.
How many charge cycles does a MacBook battery last?
Apple says most modern MacBook batteries are designed to keep 80 percent of their original capacity after 1,000 full charge cycles. Older models may have a lower rating, so check your model on Apple's support site. You can see your current count under System Information › Power › Cycle Count.
Does installing the iOS 27 beta damage the battery?
No. A beta can drain the battery faster for a few days while it re-indexes data, and early builds can have power bugs, but that is software behaviour and it does not lower the Maximum Capacity figure. If drain continues for more than a few days, check which apps use the most power in Settings › Battery and report the issue through Feedback Assistant.
Should I replace the battery or buy a new phone?
If the battery is below 80 percent and you plan to keep the phone for another year or two, a replacement is usually the better value. A new battery restores battery life but does not make an old phone faster or add features. If the device is close to the end of software support, putting the money towards a newer model may make more sense.