Where to find your iPhone's battery health information

Your iPhone stores a battery health report that you can read yourself without any tools or apps. Open Settings, then tap Battery, then Battery Health & Charging. You will see two numbers: your battery's maximum capacity and its condition.

Maximum capacity tells you what percentage of the battery's original charge it can still hold. A new iPhone shows 100%. After a year or two of normal use, you might see 95% or 90%. The condition line tells you whether the battery is normal, degraded, or needs service — most people see "Normal" here for years.

This screen also shows whether your phone is using optimized battery charging, a feature that slows charging to 80% overnight to reduce wear. You can turn this on or off, though Apple recommends leaving it on if you charge overnight regularly.

Key Takeaways

  • Maximum capacity below 80% means your battery is aging faster than normal, though it will still work.
  • If the condition line says "Service Recommended" or "Service Battery", the battery is degrading unusually fast and Apple will replace it.
  • Optimized battery charging reduces wear by pausing at 80% overnight, so turning it on extends the battery's life if you charge while sleeping.
  • Battery health naturally declines with use — seeing 90% after two years is normal and does not require action.

What the maximum capacity number actually means

Maximum capacity is a percentage of how much charge your battery can hold compared to when it was brand new. If it shows 85%, your battery can now hold 85% of the charge it held on day one. This does not mean your phone will die at 85% — it means a full charge today is equivalent to 85% of a full charge from the factory.

The decline happens because lithium batteries lose capacity every time they charge and discharge. This is not a defect; it is how the chemistry works. A battery at 85% capacity will still power your phone all day if you are not a heavy user. At 70% or below, you might notice the phone shuts down before the battery percentage reaches zero, or it drains noticeably faster than it used to.

Apple considers a battery "worn" once it drops below 80% capacity. This is the threshold where you might want to think about a replacement, though the phone will continue to work. Many people use iPhones with 70% capacity for months or years without problems.

Understanding the condition status

The condition line shows one of three messages: "Normal", "Service Recommended", or "Service Battery". Normal means your battery is aging as expected for its age and use. You will see this for most of the battery's life.

Service Recommended appears when the battery has degraded faster than normal but is not yet failing. This usually means the battery has dropped below 80% capacity sooner than typical. You can continue using the phone, but Apple is telling you a replacement would restore performance.

Service Battery means the battery is failing or has failed and needs when ready replacement. Your phone may shut down unexpectedly or refuse to charge. If you see this message, contact Apple or an authorized repair shop to schedule a battery replacement.

How to interpret your battery health over time

Battery capacity naturally declines about 1% per month with normal use, though this varies widely depending on how you charge and use the phone. A phone charged once a day might lose 10% capacity in a year. A phone charged twice a day might lose 15% in the same period. Temperature, charging speed, and how full you keep the battery all affect the rate.

Check your battery health every few months if you are concerned about it, or once a year if you just want a general sense. Write down the number so you can see the trend. If capacity is dropping faster than 2% per month, something unusual is happening — either the phone is being used very heavily, exposed to heat, or the battery itself is defective.

Do not panic if you see 90% after a year. This is normal. Do not panic if you see 80% after two years. This is also normal. Start paying attention when you see 70% or when the condition line changes from Normal to Service Recommended.

When to replace your iPhone battery

You should consider a battery replacement when maximum capacity drops below 80% and you notice the phone draining faster or shutting down early. You do not have to wait for the condition line to say Service Recommended — if 85% capacity is affecting your daily use, a replacement will help.

Apple will replace the battery for a flat fee if the phone is out of warranty. The cost varies by model but typically ranges from $50 to $100. If the phone is still under warranty or AppleCare+, the replacement is covered. If the condition line says Service Battery, the replacement is usually covered even if warranty has expired, because this indicates a defect.

You can have the battery replaced at an Apple Store, an Apple Authorized Service Provider, or through Apple's mail-in repair service. The process usually takes one to three days at a store, or one to two weeks by mail. Your data stays on the phone during the replacement.

Why your battery health matters less than you think

A battery at 85% capacity will power most iPhones through a full day of normal use. The phone does not become unusable at 80% or 70% — it just loses some of its reserve. If you use your phone lightly, you might not notice any difference until capacity drops below 60%.

The real reason to monitor battery health is to catch a defective battery early. If your phone is six months old and already at 85% capacity, something is wrong and Apple should replace it. If your phone is three years old and at 75% capacity, that is normal aging and you can decide whether the cost of replacement is worth it to you.

Battery health also matters if you plan to sell or trade in your phone. Buyers and trade-in programs check this number, and a phone with 90% capacity will be worth more than one with 70% capacity. If you are keeping the phone for years, the resale value does not matter as much as whether the battery still meets your daily needs.

Frequently Asked Questions

Is 80% battery health bad?

No. Eighty percent is Apple's threshold for "worn", but the battery still works normally. Most people do not notice any change in performance at 80%. You should consider a replacement if you see 80% and the phone is draining noticeably faster than it used to, or if you plan to keep the phone for several more years.

Can I improve my battery health?

No. Once capacity is lost, it cannot be recovered. You can slow future decline by keeping the phone cool, avoiding extreme heat, using optimized battery charging, and not letting the battery drain to zero regularly. But the damage that has already happened is permanent.

Why does my battery health drop so fast?

Fast decline usually means heavy use, frequent charging, or exposure to heat. If your phone is charged three or four times a day, capacity will drop faster than a phone charged once a day. Heat from direct sunlight, car dashboards, or heavy apps also accelerates decline. If the phone is less than a year old and already below 90%, contact Apple — this may indicate a defective battery.

Do I need to replace my battery if it is at 85%?

Not unless you notice the phone draining faster or shutting down early. Eighty-five percent capacity is still healthy. Replace it when the battery no longer meets your needs, or if Apple's condition line says Service Recommended or Service Battery.

Will replacing the battery fix my phone if it is slow?

Only if the slowness is caused by the battery. iPhones with very low battery capacity sometimes throttle performance to prevent unexpected shutdowns. If your phone is slow and battery capacity is below 50%, a replacement may help. If capacity is above 70%, slowness is likely caused by something else.