How to check battery health on a laptop, an iPhone or an Android phone

A battery wears a little every time it is charged and used. After a few years, a laptop that lasted a working day or a phone that lasted until bedtime starts to run short. Before you blame the charger, the apps or the weather, it is worth seeing what the battery itself says. Windows, macOS, iPhones, recent Pixels and Samsung Galaxy phones can all tell you, and reading it takes a few minutes.

This guide shows where to find it on a Windows laptop, a Mac, an iPhone, a Google Pixel and a Samsung Galaxy, what the figures mean, and when a new battery is worth considering. Every menu path comes from the maker’s own support page, checked on 3 November 2026. Menus move between versions, so if yours looks different, the linked page is the one to trust.

The two figures that matter

The first is capacity compared with new. A battery that held its full design charge when new might hold 85 per cent of it a few years later. Apple calls this maximum capacity, the Windows battery report shows it as full charge capacity next to design capacity, and Google calls it battery capacity.

The second is charge cycles. A cycle is a full battery’s worth of use, not one charge: Apple’s example is using half the charge one day and half the next, recharging in between, which counts as one cycle, not two. Batteries are rated to keep a certain share of their capacity for a certain number of cycles, and for both Apple and Google that share is 80 per cent.

On a Windows laptop: the battery report

Windows writes a detailed battery report with one command. Microsoft’s steps for Windows 11, from its page on caring for your battery, are:

1. Select Start, type Command prompt, then press and hold (or right-click) Command prompt, choose Run as administrator and select Yes.
2. Type powercfg /batteryreport and press Enter.
3. The window shows where the report was saved. It is an HTML file: open File Explorer, go to that folder and double-click the report, and it opens in your web browser.

Microsoft’s reference for the command describes the report as battery usage over the lifetime of the system. Microsoft suggests starting with the Installed battery, Recent usage and Battery usage sections. Under the installed battery, look for two figures, both in milliwatt-hours (mWh):

• Design capacity: in Microsoft’s words, the estimated energy capacity of a new battery of this type.
• Full charge capacity: the energy the battery holds now when it is fully charged.

Divide the full charge capacity by the design capacity and multiply by 100, and you have the battery’s capacity as a percentage of new. A design capacity of 50,000 mWh and a full charge capacity of 40,000 mWh, for example, is 80 per cent.

Microsoft’s page does not give a figure at which to replace a laptop battery. The 80 per cent mark that Apple and Google use is a sensible yardstick, and below it you should expect less time away from the charger. Microsoft’s own advice for slowing the wear is on the same page: avoid using or charging the laptop somewhere hot, keep the charge roughly between 20 and 80 per cent when you can, and turn on Smart charging if your laptop supports it.

On a Mac laptop: Battery Health and the cycle count

Choose Apple menu > System Settings, then click Battery in the sidebar (you may need to scroll down) and look at Battery Health. Apple’s guide lists two conditions:

• Normal: the battery is functioning normally.
• Service Recommended: the battery’s ability to hold a charge is less than when it was new, or it is not functioning normally. Apple’s battery service page says you can safely keep using the Mac.

Click the info button next to the condition to see Maximum Capacity, the battery’s capacity compared with when it was new, on the Mac models that show it. If there is no Battery Health in your settings, Apple says you have an older Mac or older macOS: hold the Option key and click the battery status menu in the menu bar, which may show Replace Soon, Replace Now or Service Battery.

The cycle count is elsewhere. Hold the Option key, click the Apple menu and choose System Information, then select Power under Hardware. The count is under Battery Information. Apple’s cycle count table gives a maximum of 1,000 cycles for every Mac laptop it lists from 2010 onwards, and fewer for some older models. Apple says a Mac battery is designed to keep up to 80 per cent of its original capacity at its maximum cycle count, that you can carry on using it beyond that with less battery life, and that for best performance you should replace it when it reaches the maximum.

Apple also warns that third-party apps reporting battery health may not be accurate, and says to rely on what macOS reports. If you bought AppleCare for the Mac, Apple says the plan covers a new battery once yours holds less than 80 per cent of its original capacity.

On an iPhone: Battery Health

On an iPhone 15 or later with iOS 17.4 or later, go to Settings > Battery > Battery Health. Apple’s page on iPhone 11 and later says it shows the battery’s health and maximum capacity, whether a replacement is recommended, the cycle count, and when the battery was made and first used. On an iPhone 11, 12, 13 or 14, the menu is Settings > Battery > Battery Health & Charging.

Maximum capacity is the battery’s capacity compared with when it was new, and Apple notes that a brand-new phone can show slightly less than 100 per cent, depending on how long it sat between being made and being activated. Apple’s figures for what to expect:

• iPhone 14 models and earlier: designed to keep 80 per cent of their original capacity at 500 complete charge cycles, under ideal conditions.
• iPhone 15 models and later: 80 per cent at 1,000 complete charge cycles.

Apple’s battery and performance page explains the messages under Peak Performance Capability. If the battery could not deliver enough power and the iPhone shut down unexpectedly, iOS may apply performance management to stop it happening again, and the screen says so. If the battery has worn a long way, you see “Your battery’s health is significantly degraded”, which Apple says is not a safety issue, though it can mean more noticeable battery and performance problems.

If the screen says “Unable to verify this iPhone has a genuine Apple battery”, Apple says the figures on it may not be accurate. Our guide to genuine, compatible and used parts explains what that message means after a repair.

Apple’s iPhone battery service page says AppleCare covers a new battery once the capacity drops below 80 per cent. Without it, Apple’s warranty does not cover a battery that has worn down through normal use.

On a Google Pixel

On a Pixel 8a or later, go to Settings > Battery > Battery health. Google’s page on Pixel batteries lists three statuses:

• Normal: the battery’s capacity is within normal limits.
• Reduced: the capacity has fallen below 80 per cent, and Google suggests considering a replacement.
• Unavailable: the phone cannot determine the status.

For the estimated capacity itself, tap Battery health > Battery capacity. The cycle count is under Settings > About phone > Battery information, with the date the battery was made and the date of first use.

Google’s page lists the feature by model: it is on the Pixel 8a and later, not on the Pixel Tablet, and the Pixel 6a, 7, 7 Pro, 7a, 8 and 8 Pro do not show a battery health status. Google recommends a new battery for the Pixel 3 to Pixel 8 Pro and the Pixel Fold when the capacity is below 80 per cent or the battery reaches 800 cycles, and for the Pixel 8a and later below 80 per cent or at 1,000 cycles. On the Pixel 6a and later, battery health assistance adjusts the battery’s maximum voltage in stages from 200 cycles to 1,000, so Google says you may notice small decreases in running time as the battery ages.

On a Samsung Galaxy

Samsung’s own route is the Samsung Members app. Samsung’s UK guide gives the steps:

1. Open the Samsung Members app.
2. Tap the Support tab.
3. Tap Get Started under Phone diagnostics.
4. When the diagnosis finishes, tap the Battery status icon.

The result is one of three words. Normal means no issues. Weak means the battery’s efficiency may have dropped through use or conditions. Bad means battery life has significantly degraded, and Samsung suggests visiting a Samsung Support Centre for advice. Samsung’s page on when to replace a Galaxy battery adds that the phone may show a battery performance degradation alert when performance has dropped significantly, and that menu names can vary by model, software and app version.

For other Android phones, the maker’s own support pages are the place to look, because the menus differ from brand to brand.

What the figures mean, and when a new battery is worth it

A worn battery is not a fault, and a figure under 80 per cent is not an emergency. Apple says you can keep using a Mac battery beyond its maximum cycle count, and that an iPhone battery whose health is significantly degraded is not a safety issue. The real question is whether the battery still gets you through your day.

A new battery is worth considering when:

• the capacity is below about 80 per cent and the running time no longer fits how you use the device;
• the maker’s own wording has turned: Service Recommended on a Mac, a replacement recommended on an iPhone, Reduced on a Pixel, Weak or Bad on a Galaxy;
• the device switches off unexpectedly, especially in the cold, which Samsung lists as a sign that a battery is nearing the end of its life;
• the rest of the device is worth keeping. On an older machine with other faults, our guide to whether a laptop is worth repairing walks through the decision.

If the figures look healthy and the battery still drains fast, the battery may not be the problem: a hot machine, a bright screen or something running in the background drains any battery. If a phone will not charge at all, instead of running short, our guide to why a phone will not charge works through the cheaper causes first, and for a laptop that says it is plugged in but not charging, see laptop will not charge.

A swollen battery is different

Everything above is about wear. Swelling is a fault, and it does not wait. On a laptop, the trackpad lifts, the base bows or the machine rocks on a flat desk. On a phone, the screen or the back starts to lift away from the frame.

Microsoft says that if a battery expands beyond the device’s casing, you should stop using the device immediately, handle it with care and avoid pressing on or puncturing the battery. Google’s list for a Pixel adds: do not press on the glass to push the battery back, do not try to prise the phone open or fix the battery yourself, and do not put the device in household waste. Samsung says not to attempt a self-repair on a phone with a swollen battery.

Our advice is the same for every device: stop charging it, switch it off, and get it seen to promptly.

If it is time for a new battery

We replaced a worn battery in a Dell Latitude 5290 and photographed every step, from the base coming off to the first full charge, when the battery report is read again to confirm the new capacity: replacing a laptop battery, start to finish. Our laptop battery replacement page explains how we confirm it is the battery, and not the charger or the port, before anything is ordered, and phone repair covers iPhone and Android batteries.

Tell us the make, the model and what the battery screen says, and we will tell you whether a new battery is worth doing. We come to you across Leeds, West Yorkshire, Harrogate, Knaresborough and York.