iPhone battery lifespan depends on your model and how you use it

An iPhone battery typically lasts between two and three years before it noticeably loses the ability to hold a charge through a full day. Apple designs iPhone batteries to retain 80 percent of their original capacity after 500 complete charge cycles — one cycle means draining the battery fully and charging it back to 100 percent. After that point, the battery degrades gradually, losing roughly 1 percent of capacity per 100 additional cycles.

The actual time before you need a replacement depends on how often you charge your phone and what you use it for. A person who charges their iPhone once daily will hit 500 cycles in about 20 months. Someone who charges twice daily will reach that threshold in 10 months. Heavy use — streaming video, gaming, or running location services constantly — drains the battery faster and creates more charge cycles in the same calendar time.

Temperature also matters. Batteries degrade faster in hot conditions (above 95°F) and very cold conditions (below 32°F). If you regularly use your iPhone in a hot car or leave it in direct sunlight, you may see noticeable capacity loss within 18 months.

Key Takeaways

  • iPhone batteries are designed to retain 80 percent capacity after 500 complete charge cycles, which typically takes 18 to 24 months of normal daily use.
  • A complete charge cycle means draining the battery fully and recharging to 100 percent, not plugging in for a quick top-up.
  • Frequent charging, heavy app use, and exposure to heat all speed up battery degradation and may require replacement sooner than two years.
  • You can check your battery's current health percentage in Settings > Battery > Battery Health & Charging on any iPhone running iOS 16 or later.
  • Apple and authorized repair shops charge between $69 and $99 to replace an out-of-warranty battery, depending on your iPhone model.

What "battery health" percentage means and how to check it

Your iPhone displays a Battery Health percentage that tells you how much capacity your battery retains compared to when it was new. A battery at 100 percent health holds a full charge. At 80 percent health, it holds 80 percent of the original charge. At 50 percent health, a full charge lasts roughly half as long as it did when the phone was new.

To check your battery health, open Settings, tap Battery, then tap Battery Health & Charging. You will see a number labeled "Maximum Capacity" — that is your current health percentage. Below it, you may see a message about battery condition. If the battery is performing normally, no message appears. If it says "Service Recommended," the battery is degraded but still functional. If it says "Service Battery," the battery is significantly degraded and Apple recommends replacement.

This percentage is specific to your phone and does not compare you to other users. Two iPhones of the same model and age can have very different health percentages depending on charging habits and temperature exposure.

When battery degradation becomes noticeable in daily use

Most people notice their battery is aging when their phone no longer lasts a full day with moderate use. This typically happens when battery health drops to 70 to 75 percent. At that point, a phone that once lasted 15 hours might last 10 to 12 hours before needing a charge.

You may also notice that your phone shuts down unexpectedly at 20 or 30 percent battery, or that it takes longer to charge. These are signs the battery is struggling to deliver power consistently. Some users experience slower performance when the battery is degraded, because iOS throttles the processor to prevent sudden shutdowns — this is a safety feature, not a defect.

If your battery health is above 80 percent but your phone is not lasting as long as it used to, the issue may be a power-hungry app or a background process, not the battery itself. Check Settings > Battery to see which apps are using the most power.

How to slow down battery degradation

Charge your phone in a cool environment whenever possible. Avoid leaving your iPhone in a hot car, direct sunlight, or near heat sources like radiators. If your phone feels warm while charging, move it to a cooler spot or remove any thick case temporarily.

Avoid letting your battery drain completely to zero regularly. Charging from 20 percent to 80 percent creates less stress on the battery than draining it fully and recharging to 100 percent. If you use Optimized Battery Charging, available in Settings > Battery > Battery Health & Charging, your iPhone will learn your charging patterns and slow down charging past 80 percent during the night, reducing the time the battery spends at full charge.

Disable features you do not use constantly. Location services, background app refresh, and push notifications all drain the battery and create more charge cycles. Turning off Bluetooth and Wi-Fi when you are not using them also helps, though the battery drain from these is minimal compared to the screen.

Battery replacement options and costs

If your battery health has dropped below 80 percent and your phone no longer lasts through your day, you have three options: replace the battery, replace the phone, or use a portable charger.

Apple and Apple Authorized Service Providers charge between $69 and $99 to replace an out-of-warranty battery, depending on your iPhone model. Newer models (iPhone 14 and later) cost more than older ones. The replacement takes one to three business days at most locations. If your phone is still under the one-year limited warranty and the battery is defective, Apple replaces it for free.

Third-party repair shops often charge $30 to $60 for battery replacement, but they may not use genuine Apple batteries. A non-genuine battery may not report its health accurately, may not work with Optimized Battery Charging, and may degrade faster than an Apple battery. Some third-party shops offer a warranty on their work, but not all do.

A portable battery pack (also called a power bank) costs $20 to $50 and lets you charge your phone on the go without replacing the battery. This is a good temporary solution if you are waiting to replace your phone or if you only need extra power during travel.

Differences between iPhone models and battery longevity

Newer iPhone models generally have larger batteries and more efficient processors, which means they can go longer between charges and may degrade more slowly. An iPhone 15 with a 3,582 mAh battery will typically last longer per charge cycle than an iPhone 12 with a 2,815 mAh battery, assuming similar use patterns.

However, battery health percentage works the same way across all models. A two-year-old iPhone 15 and a two-year-old iPhone 12 will both have degraded to roughly 80 to 85 percent health if they were charged once daily in normal conditions. The iPhone 15 will still last longer in absolute hours because it started with a larger battery, but both will show similar percentage degradation.

Older models (iPhone 11 and earlier) sometimes show more dramatic performance drops when the battery degrades, because iOS applies more aggressive processor throttling to prevent shutdowns. This was a controversial feature that Apple addressed in later iOS versions, but it still affects older phones.

Signs your battery needs replacement soon

Beyond checking Battery Health in Settings, watch for these physical and performance signs. If your phone gets warm during normal use or while charging, the battery may be failing. If it shuts down at 15 or 20 percent battery even though Battery Health shows above 50 percent, the battery is not delivering power reliably. If your phone takes much longer to charge than it used to, or if the battery drains noticeably faster during light use, replacement is likely needed.

A swollen or visibly bulging battery is a safety hazard and requires when ready replacement. This is rare but can happen if the battery has been damaged or has degraded severely. Do not attempt to remove a swollen battery yourself — take the phone to Apple or an authorized repair shop.

Frequently Asked Questions

Does fast charging ruin your battery faster?

Fast charging creates slightly more heat and stress than standard charging, so it can degrade the battery a bit faster over time. The difference is small — a battery charged with fast charging might reach 80 percent health in 22 months instead of 24 months. If you use fast charging regularly, enable Optimized Battery Charging to reduce the impact.

Can I replace my iPhone battery myself?

Apple does not sell batteries to consumers for self-replacement on most models. Newer iPhones are designed to be difficult to open without specialized tools. If you attempt it, you risk damaging the phone's water resistance seal or the display. Professional replacement is safer and usually costs less than the tools and replacement battery would cost separately.

What is a charge cycle and how do I count them?

One charge cycle means using 100 percent of your battery's capacity, but not necessarily in one sitting. If you use 50 percent of your battery one day and 50 percent the next day, that counts as one cycle. You cannot see your cycle count in Settings on newer iPhones, but Apple can tell you during a service appointment if you ask.

Does leaving my phone plugged in overnight damage the battery?

Modern iPhones have Optimized Battery Charging enabled by default, which slows charging past 80 percent and holds it there until you typically wake up. This reduces the stress on the battery from sitting at 100 percent for hours. Leaving your phone plugged in overnight is safe and will not significantly damage the battery.

Will my battery last longer if I turn off my phone when I am not using it?

Turning your phone off occasionally does not meaningfully extend battery lifespan. Battery degradation is tied to charge cycles and time, not to whether the phone is powered on. If you want to extend battery life, focus on keeping the phone cool and avoiding frequent full drains instead.