Replace the battery if your phone is less than four years old and the battery health has dropped below 80 percent

A battery replacement costs between $69 and $99 depending on your iPhone model, while a new phone costs $800 to $1,200. If your phone still runs the apps you need, holds a charge for a full day when the battery is new, and has no cracked screen or water damage, replacing the battery almost always makes financial sense. Apple's battery replacement program covers any iPhone model currently sold, and the process takes about an hour at an Apple Store or authorized repair shop.

The real question is not whether replacement is cheaper — it always is — but whether your phone is worth keeping. A four-year-old iPhone 12 with a worn battery is still a capable phone. A seven-year-old iPhone 6s with a worn battery is approaching the point where iOS updates will slow it down, apps will crash more often, and the cost of fixing other problems (a cracked screen, a failing speaker) starts to add up.

Check your battery health before you decide. Go to Settings, then Battery, then Battery Health & Charging. If the number shown is 80 percent or higher, your battery is not the problem — something else is making your phone feel slow. If it is below 50 percent, replacement will make a noticeable difference in how long your phone lasts between charges.

Key Takeaways

  • Battery replacement costs $69 to $99 and takes about an hour, while a new iPhone costs $800 to $1,200.
  • Check your actual battery health in Settings — Battery — Battery Health & Charging to confirm the battery is the problem.
  • If your phone is less than four years old and works otherwise, battery replacement almost always makes financial sense.
  • If your phone is older than six years, factor in the cost of fixing other problems that may appear soon, like a cracked screen or failing speaker.
  • Apple's battery replacement program covers all current iPhone models and includes a one-year warranty on the new battery.

How to know if a worn battery is actually your problem

A phone that shuts down at 20 percent battery, drains from 100 to 50 percent in two hours of light use, or needs charging twice a day almost certainly has a worn battery. But a phone that feels slow, crashes apps, or stutters when opening the camera might have a different problem — too many background apps, not enough storage space, or an older processor that cannot keep up with the latest iOS version.

The Battery Health number tells you the truth. If it shows 85 percent or higher, your battery is fine and replacing it will not fix the slowness. If it shows 60 percent or lower, the battery is definitely worn and replacement will help. Between 60 and 85 percent is the gray zone — the battery is aging but not yet critical, and you can wait another six months if you do not mind charging more often.

One more check: open Settings, General, iPhone Storage. If you have less than 2 GB of free space, your phone will feel slow even with a new battery. Delete old photos, videos, or apps you no longer use, then see if the phone feels faster. If it does, the battery is not the main problem.

What happens when you replace an iPhone battery at Apple

You can walk into any Apple Store or visit an Apple Authorized Service Provider and ask for a battery replacement. You do not need an appointment for most models, though calling ahead during busy hours saves time. Bring your phone and a form of payment.

The technician will run a diagnostic to confirm the battery is worn, then replace it while you wait. The whole process takes 30 minutes to an hour. Your data stays on the phone — nothing is erased. Apple backs the new battery with a one-year warranty, which covers defects but not normal wear.

The cost depends on your model. iPhones from the current year and the previous two years cost $69. Older models cost $79 to $99. If your phone is still under AppleCare+, battery replacement is free if the battery health has dropped below 80 percent.

When a battery replacement is not worth it

If your phone has a cracked screen, water damage, or a failing speaker, the math changes. Fixing a cracked screen costs $279 to $399 depending on the model. Fixing water damage can cost $200 to $500. If you are facing $300 in repairs on top of a $79 battery replacement, you are at $380 to $580 — getting close to the cost of a refurbished phone or a budget new model.

A phone older than six years is also a borderline case. iOS updates slow down older processors, and apps crash more often. You might replace the battery and find that the phone still feels sluggish because the processor cannot handle the current iOS version. In that case, the battery replacement buys you another year or two, but not much more.

If your phone is older than seven years, consider whether you actually want to keep it. Parts become harder to find, repair costs rise, and the phone may not receive security updates much longer. A battery replacement might extend its life by a year, but you will probably want a new phone within 18 months anyway.

Refurbished and third-party battery options

Some repair shops offer third-party batteries that cost $30 to $50, undercutting Apple's price. These batteries work, but they come with no warranty and vary widely in quality. Some last as long as Apple batteries; others degrade faster or hold less charge from the start. If you are willing to take that risk and your phone is already old, a cheap third-party battery might be worth it. If your phone is newer and you plan to keep it for several more years, Apple's battery is the safer choice.

Refurbished iPhones with new batteries cost $400 to $700 depending on the model and condition. If you are comparing a $79 battery replacement on your current phone to a $500 refurbished phone, the battery replacement wins. If your current phone is six years old and you are comparing a $79 battery replacement to a $400 refurbished phone that is only two years old, the refurbished phone might be the better long-term investment.

How long a new battery will last

Apple designs iPhone batteries to retain 80 percent of their capacity after 500 full charge cycles. One charge cycle is a full drain from 100 to zero percent, or the equivalent spread across multiple days. Most people complete 200 to 300 cycles per year, which means a new battery should last two to three years before it drops below 80 percent again.

Your actual mileage depends on how you charge. Leaving your phone plugged in overnight, charging it multiple times a day, or letting it get very hot while charging all wear the battery faster. Charging to 80 percent and letting it drain to 20 percent, keeping the phone cool, and charging overnight slowly extends battery life.

If you replace the battery now and keep the phone for another three years, you will probably need a second battery replacement before you upgrade. That is still cheaper than buying a new phone, but it is worth factoring into your decision if you are on the fence.

Frequently Asked Questions

Will replacing the battery make my old iPhone feel faster?

Only if the slow performance is actually caused by the battery. A worn battery can trigger power management features that slow down the processor to prevent shutdowns. Check Battery Health in Settings first — if it is below 60 percent, replacement might help. If it is above 80 percent, the slowness is something else and a new battery will not fix it.

Can I replace the battery myself?

You can, but it is risky. iPhones are glued together, and opening one without the right tools can crack the screen or damage the logic board. A DIY kit costs $20 to $40, but if something goes wrong, repair costs jump to $300 or more. For most people, paying Apple $79 is worth the warranty and the certainty that nothing else will break.

What should I do with my old battery after replacement?

Apple takes the old battery back and recycles it. Do not throw it in the trash — lithium batteries are a fire hazard in landfills. If you go to an Apple Store, they handle recycling automatically. If you use a third-party repair shop, ask whether they recycle the old battery or if you need to take it to a recycling center yourself.

Does AppleCare+ cover battery replacement?

Yes, if the battery health has dropped below 80 percent. AppleCare+ costs $99 to $379 depending on the model and covers accidental damage, hardware failures, and battery degradation. If you already have AppleCare+, battery replacement is free. If you do not, it costs $69 to $99.

Is it worth buying a new phone instead of replacing the battery?

Only if your phone is more than six years old, has other damage that needs repair, or you want the features in a newer model. A $79 battery replacement on a four-year-old phone that otherwise works is almost always cheaper than a $900 new phone. If you are keeping the phone for another two to three years, the battery replacement pays for itself in the first month.