A new iPhone battery lasts two to three years under normal use
An iPhone battery degrades over time, and Apple designs them to retain 80 percent of their original capacity after 500 full charge cycles. A charge cycle means draining the battery from 100 percent to zero and back to 100 percent—not necessarily in one day. Under typical daily use, most people hit around 200 to 300 cycles per year, which means a new battery reaches that 80 percent threshold in roughly two to three years.
After that point, the battery still works, but it holds less charge. Your phone may shut down at 20 percent battery even though it shows 20 percent, or it may need charging twice a day instead of once. The battery itself does not fail suddenly; it straightforward becomes less useful.
Real-world lifespan varies based on how you use your phone. Heavy users who charge daily and run demanding apps may see noticeable decline in 18 months. Light users who charge every other day might get four years before the battery feels degraded. Temperature also matters—keeping your phone cool extends battery life, while heat accelerates wear.
Key Takeaways
- iPhone batteries are designed to retain 80 percent capacity after 500 charge cycles, which typically takes two to three years of normal daily use.
- A degraded battery does not mean your phone stops working—it means the battery holds less charge and may need more frequent charging.
- You can check your battery's current health in Settings > Battery > Battery Health & Charging to see the maximum capacity percentage.
- When capacity drops below 80 percent, Apple offers battery replacement at a set price rather than replacing the entire phone.
- Keeping your phone cool and avoiding extreme heat extends battery lifespan, as does limiting the number of full discharge cycles.
How to check your battery's current health
You do not have to guess whether your battery is degrading. Open Settings, tap Battery, then tap Battery Health & Charging. You will see a number labeled "Maximum Capacity"—this is the percentage of the original charge your battery can now hold. If it shows 85 percent, your battery holds 85 percent of what it held when new.
Below that, you will see "Condition"—Apple labels it as "Normal" if capacity is above 80 percent. Once it drops to 79 percent or lower, the label changes to "Degraded." This is the point where Apple considers the battery worn enough to replace.
The same screen shows "Charging Optimization," which is a feature that slows charging speed to reduce wear. If you leave your phone plugged in overnight regularly, turning this on can extend battery life by a few months.
When to replace your iPhone battery
You do not have to replace the battery the moment it hits 80 percent capacity. Many people use phones with 70 or 60 percent capacity without major inconvenience. Replace it when the phone's behavior bothers you—when it needs charging twice a day, shuts down unexpectedly, or the reduced capacity interferes with your work or travel.
If your phone is still under warranty or covered by AppleCare+, battery replacement is free if capacity has dropped below 80 percent. Without coverage, Apple charges a flat fee for battery replacement, which varies by iPhone model but typically ranges from $50 to $70. This is usually cheaper than replacing the entire phone.
Some third-party repair shops offer battery replacement for less than Apple's price, though quality and warranty coverage vary. If you choose a third-party shop, confirm they use genuine or high-quality replacement batteries—cheap batteries may degrade faster or cause other problems.
Factors that wear out batteries faster
Heat is the biggest enemy of iPhone batteries. Leaving your phone in a hot car, using it while charging, or running heavy apps in warm weather all accelerate degradation. Lithium batteries lose capacity permanently when exposed to high temperatures, even if the phone cools down later.
Charging habits also matter. Letting your battery drain completely to zero regularly, or keeping it plugged in at 100 percent for hours, both cause extra wear. The gentlest pattern is charging to 80 percent and letting it drop to 20 percent before charging again, though most people do not follow this precisely and still get normal lifespan.
Running demanding apps constantly—heavy gaming, video editing, or streaming—generates heat and draws power intensely, which stresses the battery more than light browsing or messaging. If you use your phone heavily for work, expect the battery to degrade faster than someone who uses it casually.
How to extend your battery's lifespan
Keep your phone cool. Avoid leaving it in direct sunlight, in a car on a hot day, or in a pocket against your body during exercise. If your phone gets warm during use, close apps and let it cool before charging.
Use Low Power Mode when the battery drops below 20 percent, or even at 30 percent if you are away from a charger. This reduces processor speed and background activity, which slows the drain and generates less heat. You can also enable Optimized Battery Charging in Settings > Battery > Battery Health & Charging, which learns your charging patterns and slows charging speed overnight to reduce wear.
Avoid wireless chargers if possible—they generate more heat than wired charging. If you must charge wirelessly, use a fan or keep the phone in a cool environment. Unplug your phone once it reaches 100 percent rather than leaving it plugged in for hours.
What happens when you replace the battery
When you take your phone to Apple or an authorized repair shop for battery replacement, they remove the old battery and install a new one. The process takes 30 minutes to an hour at most Apple Stores, though you may need an appointment. Your data stays on the phone—the technician does not erase it.
After replacement, your phone's battery health will show close to 100 percent maximum capacity. The new battery will follow the same degradation curve as the original, so you can expect another two to three years before it noticeably declines again.
If you use a third-party repair shop, ask whether they offer a warranty on the replacement battery. Reputable shops typically may provide the battery for at least one year. Avoid shops that cannot tell you the battery's source or offer no warranty.
Frequently Asked Questions
Can I replace my iPhone battery myself?
Apple does not sell batteries to consumers for self-installation, and opening an iPhone yourself voids the warranty. The battery is glued to the phone's interior, making removal difficult without damaging other components. Unless you have electronics repair experience, professional replacement is safer and more reliable.
Does turning off background app refresh extend battery life?
Yes, but only slightly. Turning off background app refresh in Settings > General > Background App Refresh reduces power draw, especially if many apps are refreshing data. The effect is most noticeable if you have dozens of apps enabled. For most people, it saves 5 to 10 percent of daily battery drain.
Is it bad to charge my iPhone every night?
Charging every night is normal and does not significantly harm the battery. Modern iPhones are designed for daily charging. The real wear comes from keeping the battery at 100 percent for hours after it finishes charging, or from heat during charging. If you charge overnight, Optimized Battery Charging slows the final charge to reduce this wear.
Why does my iPhone shut down even though the battery shows 20 percent?
A degraded battery cannot deliver the power the phone needs at that moment, so the phone shuts down to protect itself. This happens when maximum capacity has dropped significantly—usually below 70 percent. It is a sign the battery needs replacement soon, as the phone will become increasingly unreliable.
Does using a case affect battery lifespan?
Yes, thick cases trap heat around the phone, which accelerates battery wear. If you use a case, choose a thin one or remove it during charging. Removing the case for an hour while the phone cools can help offset the heat buildup from daily use.