Check Your Battery Health First

Before you replace anything, find out whether your battery is actually failing or whether something else is draining power. Go to Settings > Battery > Battery Health & Charging. You will see a percentage labeled Maximum Capacity. This tells you how much charge your battery can hold compared to when it was new.

If the number is above 80 percent, your battery is still in decent shape—the problem is likely a background app, a setting that drains power, or an older iOS version. If it is below 80 percent and your phone is more than two years old, the battery has degraded naturally and replacing it will usually fix the problem. If it is below 80 percent and your phone is newer, a hardware fault or a software bug may be the cause.

You will also see a Charging Health section. If it says "Service Recommended" or "Service Battery," Apple has detected a fault and the battery should be replaced by a technician.

Key Takeaways

  • Check your battery's maximum capacity in Settings > Battery > Battery Health & Charging to see whether the battery itself has degraded or something else is draining power.
  • If your maximum capacity is above 80 percent, turn off background app refresh, reduce screen brightness, and check for iOS updates before considering a replacement.
  • Force-close apps running in the background, disable location services for apps that do not need it, and turn off push notifications to cut power drain when ready.
  • If your maximum capacity is below 80 percent or Apple recommends service, you can replace the battery yourself using a kit or take the phone to Apple or a repair shop.
  • Replacing an iPhone battery yourself takes 30 to 90 minutes depending on the model and your experience; professional replacement usually takes one to three hours.

Turn Off Background App Refresh and Location Services

Apps running in the background consume battery even when you are not using them. Go to Settings > General > Background App Refresh and toggle it off entirely, or turn it off for individual apps by unchecking them in the list. This stops apps from checking for updates and syncing data when your phone is locked.

Location services also drain the battery quickly. Go to Settings > Privacy & Security > Location Services and turn it off for apps that do not need it. Maps, weather, and find-my-friends apps need location; news apps and games usually do not. You can also set location to "While Using" instead of "Always" for most apps.

Check which apps are using the most battery by going to Settings > Battery and looking at the list under Battery Usage by App. If an app you rarely use is near the top, either uninstall it or turn off its background refresh.

Reduce Screen Brightness and Enable Low Power Mode

The screen is usually the biggest battery drain. Go to Settings > Display & Brightness and turn off Auto-Brightness, then set brightness to 30 to 40 percent for everyday use. You can raise it when you need it. Alternatively, enable Low Power Mode by going to Settings > Battery and toggling it on. This reduces performance slightly but cuts battery drain by 15 to 20 percent.

If you use an iPhone 12 or newer, you can also turn off the 120Hz refresh rate. Go to Settings > Display & Brightness > Motion and toggle off 120Hz. This makes scrolling slightly less smooth but saves noticeable battery life.

Update iOS and Close Apps Running in the Background

Outdated iOS versions sometimes have battery-drain bugs. Go to Settings > General > Software Update and install any available update. Restart your phone after the update finishes.

Close apps that are running in the background by swiping up from the bottom of the screen (or swiping down from the top-right corner on iPhone X and newer) and swiping up on each app card. This does not uninstall them—it just stops them from running. Do this before you charge your phone overnight or when you are not using it.

Replace the Battery Yourself or Take It to a Repair Shop

If your maximum capacity is below 80 percent and you have tried the steps above, the battery needs to be replaced. You have three options: take it to Apple, take it to an authorized repair shop, or replace it yourself.

Apple replacement: Go to apple.com/support or call Apple Support to book a Genius Bar appointment. Apple will replace the battery for a flat fee (usually $69 to $99 depending on the model). The phone stays at the store for one to three hours, and you get a new battery with a one-year warranty. Apple also backs up your data before the repair.

Third-party repair shop: Independent repair shops often charge $40 to $80 and can usually do the work the same day. Call ahead to confirm they have the battery in stock for your model. The warranty is usually shorter than Apple's (30 to 90 days), but the repair is faster and cheaper.

DIY replacement: You can buy a battery replacement kit online (usually $20 to $40) and replace it yourself. The process takes 30 to 90 minutes depending on your phone model and experience. You will need a pentalobe screwdriver (included in most kits), a heat gun or hair dryer, and patience. Search YouTube for "[your iPhone model] battery replacement" to find a step-by-step video before you start. The main risks are damaging the screen or the logic board if you explore too much heat or pry too hard. If you are not comfortable with small electronics, a repair shop is safer.

Prevent Battery Degradation Going Forward

Batteries degrade faster when they are exposed to heat or kept at 100 percent charge constantly. Keep your phone out of direct sunlight and away from hot surfaces. If you use your phone while charging, it heats up and the battery ages faster.

Enable Optimized Battery Charging by going to Settings > Battery > Battery Health & Charging and toggling it on. This slows charging to 80 percent overnight and only charges to 100 percent when you need it, which extends the battery's lifespan by months or years.

Avoid letting your battery drop to 0 percent regularly. Charge it when it reaches 20 percent if you can. If you are not using your phone for weeks, charge it to 50 percent and store it in a cool place.

Frequently Asked Questions

How long does an iPhone battery last before it needs replacing?

Most iPhone batteries are designed to hold 80 percent of their capacity after 500 full charge cycles, which is roughly two to three years of normal use. After that, the battery degrades gradually. You do not have to replace it when ready at 80 percent—many people use their phones for another year or two—but performance and battery life will decline.

Can I replace an iPhone battery without losing my data?

Yes. If you go to Apple or an authorized repair shop, they back up your data before the repair. If you replace it yourself, your data stays on the phone because the battery is separate from the storage. Just make sure your phone is off before you start.

What if my iPhone battery is swollen?

A swollen battery is a safety hazard and should be replaced when ready. Do not try to replace it yourself—take the phone to Apple or a repair shop right away. A swollen battery can catch fire or leak chemicals. Do not use the phone while you wait for the repair.

Why is my iPhone still draining fast after I replaced the battery?

The new battery is fine, but something else is draining power. Check Battery Usage by App in Settings > Battery, turn off background app refresh for apps you do not need, reduce screen brightness, and make sure you are running the latest iOS version. If the problem persists, a hardware fault (like a failing charging port or logic board) may be the cause, and you should take the phone to a repair shop for diagnosis.

Is it cheaper to replace the battery or buy a new phone?

A battery replacement costs $40 to $100 and takes one to three hours. A new phone costs $300 to $1,200. If your phone is less than four years old and works otherwise, replacing the battery is almost always cheaper and faster. If your phone is older, has other hardware problems, or you want a newer model anyway, a new phone may make sense.