Replace your iPhone battery when it no longer holds a full day of normal use, or when iOS tells you the battery health has dropped below 80 percent
Your iPhone battery degrades every time it charges. After roughly 500 complete charge cycles — a full drain from 100 to 0 percent — most iPhone batteries retain about 80 percent of their original capacity. At that point, you'll notice your phone dies faster, especially if you use it heavily. Apple considers this the point where replacement makes sense, and iOS will alert you when you reach it.
You don't have to wait for a failure. Replacing the battery before it becomes unreliable prevents the sudden shutdowns that happen when an old battery can't deliver the power your phone demands, even though it still shows charge remaining. A proactive replacement also costs less than repairing water damage or a cracked screen that results from a phone dying unexpectedly in your pocket.
Key Takeaways
- Check your battery health in Settings > Battery > Battery Health & Charging; if it shows below 80 percent, replacement will restore performance.
- If your iPhone shuts down unexpectedly even though the battery percentage shows charge remaining, the battery is failing and needs replacement.
- Apple's battery replacement costs between $69 and $99 depending on your model, and takes one to two hours at an Apple Store or authorized repair shop.
- Third-party repair shops often charge less but may use non-original batteries, which can affect longevity and may void your warranty.
- Replacing the battery before it fails prevents unexpected shutdowns that can damage other components or cause data loss.
How to check your battery health right now
Open Settings on your iPhone, then go to Battery, then Battery Health & Charging. You'll see a percentage labeled "Maximum Capacity" — this is how much charge your battery can hold compared to when it was new. You'll also see a "Condition" line that says either "Normal" or "Service Recommended."
If Maximum Capacity is above 80 percent and Condition says Normal, your battery is still healthy. If it's between 70 and 80 percent, you're in the zone where replacement becomes worthwhile. Below 70 percent, replacement is urgent — your phone will drain noticeably faster and may shut down without warning.
If Condition says "Service Recommended" or "Poor Condition," Apple is telling you the battery needs replacement now. Don't ignore this message. It means the battery can no longer reliably power your phone.
Signs your battery needs replacement before you check the percentage
You don't need to open Settings to know something is wrong. If your iPhone shuts down suddenly while the battery percentage still shows 20 or 30 percent, the battery is failing. This happens because the battery can no longer deliver the current your phone needs for demanding tasks like video recording or gaming, even though chemical charge remains inside.
Other warning signs include the phone running noticeably slower when the battery is below 50 percent, or the battery draining 10 to 15 percent per hour during normal use when it used to last all day. Some people notice their phone gets warm during normal use, which can indicate the battery is struggling.
If you're charging your phone twice a day when you used to charge it once, that's also a sign the battery capacity has dropped enough to warrant replacement. You can keep doing this indefinitely, but you're trading convenience now for a battery that will fail completely within months.
Where to get your battery replaced and what it costs
Apple Stores and Apple Authorized Service Providers handle battery replacement. Go to apple.com/repair, enter your model, and you'll see the cost for your specific iPhone. Prices range from $69 for older models to $99 for the newest ones. You can book an appointment online or call your nearest store. Replacement usually takes one to two hours if you wait, or you can leave the phone and pick it up the next day.
Third-party repair shops like uBreakiFix, Best Buy's Geek Squad, or local independent repair shops often charge $40 to $60 less. The trade-off is that some use non-original batteries, which may not last as long or perform as reliably. Ask whether they use original Apple batteries or third-party equivalents before you commit. If your iPhone is still under warranty or AppleCare+, Apple will replace the battery for free if the health has dropped below 80 percent.
Mail-in repair is also an option if you don't have a store nearby. Apple will send you a prepaid shipping label, repair the phone at a regional center, and return it to you within a week. The cost is the same as in-store replacement.
What happens if you ignore a failing battery
A battery that's reached the end of its life will eventually fail completely. Before that happens, you'll experience random shutdowns that can corrupt files you were working on, cause you to miss calls or messages, or leave you stranded without a working phone. If the shutdown happens while you're using a camera or video app, it can damage the storage system.
Repeated unexpected shutdowns also put stress on other components. The sudden power loss can affect the logic board or storage, turning a $70 battery replacement into a $300 or $400 repair. Over time, a failing battery can also cause the phone to swell inside the case, which can crack the screen or damage the display connector.
If your phone is old enough that repair costs approach the price of a new device, you may decide to replace the phone instead. But if your iPhone is otherwise working well, a battery replacement extends its useful life by two to three years for less than $100.
How to extend battery life between replacements
Once you've replaced the battery, you can slow down the next degradation by avoiding extreme temperatures — don't leave your phone in a hot car or in freezing weather for long periods. Keep your phone between 50 and 95 percent charge most of the time if you can; letting it drop to 0 percent regularly or keeping it at 100 percent constantly speeds up degradation.
Enable Optimized Battery Charging in Settings > Battery > Battery Health & Charging. This feature learns when you usually charge your phone and slows charging to 80 percent until you need it, which reduces wear. It's on by default on most iPhones.
Avoid using your phone while it's charging, especially during intensive tasks like gaming or video recording. Heat is the enemy of battery life, and charging generates heat. If your phone gets warm while plugged in, unplug it and let it cool down.
Frequently Asked Questions
Can I replace my iPhone battery myself?
You can, but it's difficult and risky. iPhone batteries are glued in place, and prying them out can damage the display or logic board. If you damage something during removal, repair costs jump to $200 or more. Unless you have experience with phone repair, it's safer and often cheaper to have a professional do it.
Will replacing the battery erase my data?
No. Battery replacement doesn't touch your storage or data. Your photos, messages, and apps will be exactly as they were before and after the repair. Apple and authorized shops don't back up or restore your phone during battery service.
How long does a new battery last?
A new original Apple battery will retain about 80 percent capacity after roughly 500 charge cycles, which typically takes two to three years of normal daily use. If you charge your phone once a day, that's about two to three years before you'll need replacement again.
Is it worth replacing the battery in an old iPhone?
If your iPhone is more than four or five years old and the battery is failing, compare the $70 to $100 replacement cost against the price of a new phone. If the phone is otherwise working well and you're not ready to upgrade, battery replacement is usually worth it. If the phone has other problems like a cracked screen or slow performance, replacement might make more sense.
What's the difference between "Normal" and "Service Recommended" battery condition?
Normal means your battery is healthy and doesn't need replacement yet. Service Recommended means the battery has degraded enough that Apple thinks you should replace it soon — usually when maximum capacity has dropped below 80 percent or the battery can no longer reliably power the phone. It's not an emergency, but you should plan to replace it within the next month or two.