Battery Health is not the same as the battery percentage in the status bar. It measures how much energy your battery can hold now compared with when it was new. A lower health number means the battery has aged and has less total capacity.
Battery Health is available on iPhone 6 and later running iOS 11.3 or newer. The setting is usually under Battery Health & Charging.
Does This Affect You?
Use this if your iPhone shows a Maximum Capacity under 100 percent and you are wondering whether that means the phone is broken or needs a replacement battery. Some decline is normal with rechargeable batteries.
What the Percentage Measures
- Lithium-ion batteries wear chemically as they go through charge cycles. That is normal, not automatically a defect.
- Maximum Capacity compares today’s battery capacity with the original capacity when the iPhone was new.
- A battery at 85 percent health can hold about 85 percent as much charge as it originally could.
- This is separate from current charge. A battery at 85 percent health can still be fully charged to 100 percent of its current smaller capacity.
So if the status bar says 100 percent, the battery is full right now. Battery Health explains how large that full tank has become after wear.
Check Battery Health
- Open Settings.
- Tap Battery.
- Tap Battery Health & Charging.
- Read Maximum Capacity.
- Check Peak Performance Capability for any note about performance management or shutdown risk.
Apple commonly uses less than 80 percent of original capacity as the battery-service threshold for AppleCare+ coverage. Even outside warranty, that is a useful marker for when a battery is meaningfully worn.
What Makes Battery Health Drop Faster
Charge Cycles
One cycle means using an amount of battery equal to 100 percent of capacity. That can be one full 0-to-100 use or several partial uses that add up. More cycles generally mean more wear.
Heat
Using or charging the iPhone in hot places, gaming while charging, leaving it in a car, or using thick cases during heavy charging can speed up battery aging.
Daily Use Still Matters Most
If Battery Health is lower but the iPhone still lasts through your day, you may not need to do anything yet. Pay closer attention when runtime becomes inconvenient, shutdowns happen, or performance warnings appear.
Sources
- Apple Support: Understand your iPhone battery usage and health
- Apple Support: Get your iPhone battery serviced
- Apple: AppleCare+ battery service coverage