Every rechargeable battery in your smartphone, laptop, tablet, or smartwatch gradually loses capacity over time. Checking battery health helps you understand how much capacity your battery has retained compared to when it was new and whether it is time for a replacement. This complete guide covers how to check battery health on iPhones, Android phones, Windows laptops, MacBooks, and tablets in 2026.
What is Battery Health?
Battery health represents the current maximum capacity of your battery compared to its original design capacity when it was brand new. A new battery starts at 100% health. Over time, as you charge and discharge the battery through hundreds of cycles, chemical aging causes the maximum capacity to gradually decrease. A battery at 80% health can only hold 80% of the charge it could when it was new, meaning shorter usage time between charges.
What is a Charge Cycle?
A charge cycle is completed when you use an amount of energy equal to 100% of your battery capacity, but not necessarily all at once. For example, if you use 50% of your battery today and recharge to full, then use 50% again tomorrow, that counts as one complete charge cycle across two days. Most modern lithium-ion batteries are designed to retain at least 80% of their original capacity after 500 complete charge cycles.
How to Check Battery Health on iPhone
Apple provides the most straightforward built-in battery health monitoring tool of any smartphone manufacturer.
Using Settings
Open the Settings app on your iPhone. Scroll down and tap Battery. Tap Battery Health and Charging. You will see two key metrics:
Maximum Capacity: This percentage shows how much charge your battery can hold compared to when it was new. A new iPhone shows 100%. After a year of typical use, this usually drops to around 90-95%. Apple considers a battery to be significantly degraded when it falls below 80%.
Peak Performance Capability: This section tells you whether your battery can still support normal peak performance. If the battery has degraded significantly, iOS may apply performance management (throttling) to prevent unexpected shutdowns. You will see a message if this is active.
Cycle Count on iPhone
Starting with iOS 17.4, Apple added the ability to check your battery cycle count directly. Go to Settings > General > About and scroll down to the battery section. You will see the Cycle Count, Manufacture Date, and First Use Date of your battery.
How to Check Battery Health on Android
Android battery health checking varies by manufacturer, as Google does not provide a universal battery health feature in stock Android.
Samsung Galaxy Devices
Samsung includes battery diagnostics in its Samsung Members app. Open Samsung Members (pre-installed on all Galaxy devices). Tap Get Help or Support at the bottom. Tap Interactive Checks or Diagnostics. Select Battery from the list of components. The app will analyze your battery and report its status as "Good," "Normal," or "Weak." While Samsung does not show an exact percentage like Apple, this gives a general indication of battery condition.
Using Dialer Codes
Some Android phones support hidden diagnostic screens accessible through dialer codes. Open your phone dialer and type *#*#4636#*#*. If supported, a testing menu will appear. Select Battery Information. This screen shows battery status, battery level, battery temperature, voltage, and technology type. The "Battery Health" field will show "Good" or "Unknown" on most devices. Note that this code does not work on all Android phones, particularly heavily customized manufacturer versions.
Using Third-Party Apps
For more detailed battery health information on Android, several trusted apps provide comprehensive diagnostics. AccuBattery is the most popular option, tracking battery health over time by measuring actual charge capacity versus design capacity. After installing AccuBattery, it takes a few charge cycles to calibrate and provide accurate readings. GSam Battery Monitor and CPU-Z also provide useful battery statistics including temperature history and discharge rates.
OnePlus and Oppo Devices
OnePlus and Oppo phones running recent versions of OxygenOS or ColorOS include built-in battery health information. Go to Settings > Battery > Battery Health. The screen shows the current maximum capacity percentage similar to iPhone, along with an estimated number of remaining effective charge cycles.
How to Check Battery Health on Windows Laptops
Windows includes a built-in battery report tool that provides detailed information about your laptop battery condition.
Generate a Battery Report
Press Windows + X and select Terminal (Admin) or Command Prompt (Admin). Type the command powercfg /batteryreport and press Enter. The system will generate an HTML report and save it to your user folder. Navigate to the file path shown in the command output (typically C:\Users\YourName\battery-report.html). Open the file in any web browser.
Reading the Battery Report
The battery report contains several important data points. Design Capacity: The original capacity of the battery as specified by the manufacturer (measured in mWh). Full Charge Capacity: The current maximum charge the battery can hold. Cycle Count: The total number of charge cycles completed. Compare Design Capacity with Full Charge Capacity to calculate your battery health percentage. For example, if Design Capacity is 50,000 mWh and Full Charge Capacity is 42,000 mWh, your battery health is approximately 84%.
How to Check Battery Health on MacBook
macOS provides easy access to battery health information for all MacBook models.
macOS Ventura and Later
Click the Apple menu and select System Settings. Click Battery in the sidebar. Click the info (i) button next to Battery Health. You will see the battery condition reported as Normal (battery is functioning normally), Service Recommended (battery holds significantly less charge than when it was new). The maximum capacity percentage is also displayed. Apple considers MacBook batteries to be consumed when they reach 80% of original capacity or 1,000 charge cycles.
Using System Information
For more detailed information, hold Option and click the Apple menu, then select System Information. Click Power in the sidebar under Hardware. This screen shows the Cycle Count, Condition, Full Charge Capacity, and Maximum Capacity percentage of your MacBook battery.
When to Replace Your Battery
Consider replacing your battery when the health drops below 80% of original capacity, as performance and battery life will be noticeably reduced. Other signs that indicate battery replacement is needed include the device shutting down unexpectedly at 20-30% battery level, the battery draining much faster than when the device was new, the device feeling unusually warm during normal use, or the battery physically swelling (which requires immediate attention and replacement).
Tips to Preserve Battery Health
Keep your device between 20% and 80% charge when possible rather than consistently charging to 100% or draining to 0%. Avoid exposing your device to extreme temperatures, both hot and cold. Use the original charger or a certified third-party charger. Enable optimized charging features (available on iOS, Samsung, and most modern devices) that learn your charging habits and delay charging past 80% until you need the full charge. Avoid using your device intensively while it is charging, as this generates additional heat.
Conclusion
Checking battery health is essential for understanding why your device may not last as long on a single charge as it used to. iPhones offer the most detailed built-in tools, while Android users can rely on manufacturer-specific features or third-party apps like AccuBattery. Windows and macOS both provide comprehensive battery reports that reveal design versus actual capacity. By monitoring your battery health regularly and following the preservation tips in this guide, you can maximize the lifespan of your device batteries in 2026.