Where to find your iPhone's battery health information

Apple built a battery health tool directly into every iPhone running iOS 16 or later. Open Settings, then tap Battery, then Battery Health & Charging. You will see two pieces of information: your Maximum Capacity (shown as a percentage) and your Charging Status.

Maximum Capacity tells you how much charge your battery can hold now compared to when it was brand new. A new iPhone battery is 100%. After a year or two of normal use, it typically drops to 80–90%. After three or four years, 70–80% is common. This number is what matters most — it directly affects how long your phone runs between charges.

If you have an older iPhone running iOS 15 or earlier, the same information lives in Settings > Battery > Battery Health, but the layout is slightly different. The percentage shown is still your Maximum Capacity.

Key Takeaways

  • Maximum Capacity below 80% means your battery is degraded; below 50% means it will drain noticeably faster than normal.
  • Charging Status tells you whether your phone is currently limiting charge to protect the battery, which happens automatically in cold weather or after heavy use.
  • Battery health degrades naturally over time and with use — this is normal and does not mean your phone is broken.
  • If Maximum Capacity drops below 50%, Apple will usually recommend a battery replacement, which you can do at an Apple Store or authorized repair shop.

What Maximum Capacity actually means

Maximum Capacity is measured in milliamp-hours (mAh), but Apple shows it to you as a percentage for simplicity. If your iPhone originally held 3,000 mAh and now holds 2,400 mAh, the display shows 80%. That 20% loss is real — your phone will not run as long on a full charge.

The speed of degradation depends on how you use your phone. Leaving it plugged in overnight, exposing it to heat, or running demanding apps constantly will wear the battery faster. Moderate use in normal temperatures slows degradation. Most people see a 10–20% drop in the first two years.

Once Maximum Capacity falls below 80%, you may notice your phone drains faster or shuts down unexpectedly when the battery is low. Below 50%, the phone becomes noticeably less reliable. Apple's warranty covers batteries that fall below 80% within the first year, but after that, replacement is out of pocket.

Understanding Charging Status

Charging Status appears right below Maximum Capacity and tells you what your phone is doing right now. Most of the time it says Normal, which means your battery is charging or holding a charge at full capacity without any limits.

If it says Optimized Battery Charging, your phone is intentionally slowing down the charge to 80% and holding it there. This happens automatically when iOS detects that you charge overnight or at the same time every day. The phone learns your routine and stops charging past 80% until you actually need the full capacity — usually in the morning. This feature extends battery lifespan by reducing the time the battery spends at 100%, which is when degradation happens fastest.

If it says Charging Limited, your phone detected that the battery is too hot or too cold and is refusing to charge above a safe level. This is a protection mechanism. Move your phone to room temperature and try again in a few minutes. If this message persists, contact Apple Support.

When to consider a battery replacement

Apple recommends a battery replacement when Maximum Capacity drops below 80% and you notice your phone draining faster than before. You do not have to wait until it reaches 50% — if the degradation bothers you, you can replace it sooner.

Battery replacement costs vary. At an Apple Store, an out-of-warranty battery replacement typically costs between $50 and $100 depending on your iPhone model. Some authorized repair shops charge less. If your phone is still under warranty or covered by AppleCare+, the replacement may be free or discounted.

Before you replace the battery, confirm that the drain is actually the battery and not a misbehaving app. Go to Settings > Battery > Battery Usage and look at which apps consumed the most power in the last 24 hours or 10 days. If one app is using far more than the others, try uninstalling it or checking for an update.

How to slow down battery degradation

You cannot stop your battery from degrading — that is chemistry, not a setting you can change. But you can slow it down significantly by managing heat and charge cycles.

Keep your phone out of direct sunlight and away from hot surfaces. Heat is the enemy of lithium batteries. If your phone gets warm during use, close apps or let it cool down before charging. Do not leave it in a hot car or on a sunny windowsill.

Avoid letting the battery drain all the way to zero regularly. Charging from 20% to 80% is gentler on the battery than charging from 0% to 100%. If you use Optimized Battery Charging (which is on by default), your phone is already doing this automatically at night.

Use a charger that matches your phone's specifications. Older or damaged chargers can deliver inconsistent power and stress the battery. Apple's official chargers and certified third-party chargers are safe.

Reading your battery health over time

Check your Maximum Capacity every few months to see the trend. Write down the percentage and the date so you can spot whether degradation is happening at a normal pace or faster than expected. A drop of 5–10% per year is typical. A drop of 20% in six months suggests something is wrong — either you are using the phone very heavily, exposing it to heat, or the battery itself is defective.

If degradation is unusually fast and your phone is still under warranty, contact Apple Support with your battery health screenshots. They can run diagnostics and may replace the battery for free if it is defective.

Frequently Asked Questions

What is a good battery health percentage?

80% or higher is considered good. At 80–90%, your phone will run nearly as long as a new one. At 70–80%, you may notice slightly shorter battery life. Below 70%, the difference becomes noticeable. Below 50%, the phone becomes unreliable.

Does checking battery health drain the battery?

No. Opening Settings and looking at Battery Health uses almost no power. You can check it as often as you want without any effect on the battery itself.

Can I replace just the battery, or do I have to replace the whole phone?

You can replace just the battery. Apple Stores and authorized repair shops offer battery replacement as a standalone service. It typically takes one to two hours. You do not need to buy a new phone.

Why does my battery health say 100% but my phone still drains fast?

A misbehaving app, not the battery, is probably the culprit. Check Settings > Battery > Battery Usage to see which apps are consuming the most power. If one app is using far more than others, try uninstalling it or updating it. Also check whether background app refresh is on for apps you do not need running in the background.

Does Optimized Battery Charging hurt my battery?

No — it helps. Optimized Battery Charging intentionally keeps your battery at 80% overnight, which slows degradation. You can turn it off in Settings > Battery > Battery Health & Charging if you need full charge every morning, but leaving it on is better for long-term battery life.