TL;DR: To check iPhone battery health, open Settings > Battery > Battery Health (on iPhone 14 and earlier it’s called Battery Health & Charging). The key number is Maximum Capacity: Apple treats a battery below 80% as worn, and that is also the point where AppleCare covers a free replacement. iPhone 15 and later also show the cycle count, manufacture date and first-use date on the same screen. Out of warranty, Apple’s US battery service runs from about $69 to $129 depending on the model.
Last updated: November 12, 2026. By Veer. Checked against Apple’s support articles on iPhone battery and performance, genuine batteries and Charge Limit, Apple’s battery repair page and published coverage of Apple’s US service prices. This is a researched guide built from official documentation, not a hands-on test of every iPhone.
Battery health is the one number that tells you whether your iPhone needs a new battery, whether a used iPhone is a fair deal, and whether AppleCare will pay for the swap. It takes about ten seconds to find, but the screen changes a little depending on your model, and a couple of the messages on it are easy to misread. Here is how to check it and what each part means.
How to check iPhone battery health in Settings
On any iPhone from the iPhone 6 onward, battery health lives in the Settings app. The only difference is the name of the menu, which changed with the iPhone 15.
iPhone 15, iPhone 16, iPhone 17, iPhone 18 and iPhone Duo:
- Open Settings.
- Tap Battery.
- Tap Battery Health.
iPhone 14 and earlier (iPhone 6 to iPhone 14):
- Open Settings.
- Tap Battery.
- Tap Battery Health & Charging.
That path comes straight from Apple’s iPhone User Guide and its support note on iPhone 11 and later. If you’re on the folding iPhone Duo, you’ll see a separate entry for each of its two batteries, and their numbers can differ slightly with normal use.
| Your iPhone | Menu path | What you’ll see |
|---|---|---|
| iPhone 15 and later (iOS 17.4+) | Settings > Battery > Battery Health | Battery health status, Maximum Capacity, cycle count, manufacture date, first use |
| iPhone 11 to iPhone 14 | Settings > Battery > Battery Health & Charging | Maximum Capacity, Peak Performance Capability |
| iPhone 6 to iPhone XS/XR | Settings > Battery > Battery Health (& Charging on newer iOS) | Maximum Capacity, performance management status |
| iPhone Duo | Settings > Battery > Battery Health | Separate details for Battery 1 and Battery 2 |
What “Maximum Capacity” means
Maximum Capacity is how much charge your battery can hold today compared with when it was new. A reading of 90% means a full charge now gives you roughly 90% of the runtime the phone had out of the box.
Apple says in its battery and performance article that a brand-new phone can show slightly under 100%, depending on how long it sat between manufacture and activation. So 99% on a new iPhone isn’t a fault.
Here’s a practical way to read the number:
| Maximum Capacity | What it means | What to do |
|---|---|---|
| 95–100% | New or nearly new | Nothing |
| 85–94% | Normal wear for a phone that’s 1–2 years old | Nothing, unless battery life annoys you |
| 80–84% | Getting close to Apple’s worn threshold | Start pricing a replacement; check AppleCare status |
| Below 80% | Apple considers the battery worn | Replacement is free with AppleCare; paid otherwise |
The 80% line matters for two reasons. Apple designs batteries to still hold 80% after a set number of charge cycles, and AppleCare’s battery service only kicks in “if the capacity drops below 80%.”
How to check iPhone battery cycle count
On iPhone 15 and later with iOS 17.4 or newer, the cycle count sits on the same Battery Health screen, along with the battery’s manufacture date and date of first use. Older iPhones (iPhone 14 and earlier) don’t show a cycle count anywhere in Settings.
A charge cycle isn’t the same as plugging in once. Apple counts one cycle each time you’ve used an amount equal to 100% of the battery’s capacity, so using 50% today and 50% tomorrow adds up to one cycle.
According to Apple:
- iPhone 14 models and earlier are designed to keep 80% of original capacity at 500 complete charge cycles under ideal conditions.
- iPhone 15 models are designed to keep 80% at 1,000 complete charge cycles under ideal conditions.
Apple’s article doesn’t list a separate figure for newer models, and real-world results depend on heat and charging habits. Still, the cycle count is the best sanity check when buying a used iPhone 15 or later: a phone with 900 cycles and 88% capacity has been cared for; one with 300 cycles and 82% probably lived in a hot car.
What the Peak Performance messages mean
Under Maximum Capacity, the Battery Health screen can show one of several messages. Most of the time you’ll see the first one.
- “Your battery is currently supporting normal peak performance.” All good.
- “Performance management has been applied…” The phone shut down unexpectedly because the battery couldn’t deliver peak power, so iOS is now capping peak speed to stop it happening again. You can tap Disable, but you can’t turn it back on yourself; it re-enables after another unexpected shutdown.
- “Your battery’s health is significantly degraded.” Apple says this is not a safety issue and you can keep using the phone, but expect shorter battery life and slowdowns until the battery is replaced.
- “Unable to verify this iPhone has a genuine Apple battery.” Shown on iPhone XS, XS Max, XR and later. The health numbers on this screen may not be accurate.
On iPhone 11 and later, Apple says its hardware and software system reduces the effect of an aging battery, so slowdowns tend to be less noticeable than on older models. When they do appear, Apple lists longer app launch times, lower frame rates, dimmer backlight and lower speaker volume.
How to check if your iPhone battery was replaced
If you’re buying a used iPhone, also check Settings > General > About. On iPhone XR, XS and later, this screen shows parts and service history, according to Apple’s genuine battery page:
- Genuine next to Battery means the repair used genuine Apple parts and processes.
- Used (iPhone 15 and later on iOS 18 or newer) means a genuine battery that was previously in another iPhone.
- Unknown Part means a non-genuine or unverifiable battery.
- Finish Repair means a new Apple battery was fitted but the repair process wasn’t completed.
Can you check battery health without activating the iPhone?
Not through Apple. The Battery Health screen is inside Settings, so the phone has to be set up first. Apple doesn’t document any official way to read battery health on a locked or unactivated iPhone, by serial number, or from a Mac or Windows PC.
Third-party desktop tools that claim to read battery data over USB do exist, but they aren’t Apple tools and their readings aren’t guaranteed. If you’re buying from a seller, the simplest route is to ask them to open Settings > Battery > Battery Health in front of you (or on a video call) before you pay.
A factory reset doesn’t change battery health, because the reading reflects the battery’s physical condition rather than anything stored in your account. Once you get through setup, the same Settings path works.
How much does an iPhone battery replacement cost?
If your Maximum Capacity is below 80% and you have AppleCare, battery service costs nothing. Without AppleCare, Apple’s one-year limited warranty covers a defective battery but not normal wear, so you’ll pay a fee.
Apple doesn’t publish a single printed price list; its repair page gives an estimate when you pick your model. Based on Apple’s US prices as reported by 9to5Mac and AppleScoop (checked November 9, 2026):
| iPhone model | Apple US battery service (out of warranty) | With AppleCare (below 80%) |
|---|---|---|
| iPhone 18 Pro, 18 Pro Max | $129 | $0 |
| iPhone 17 Pro, 17 Pro Max, iPhone Air, 16 Pro, 16 Pro Max | $119 | $0 |
| iPhone 17, 17e, 16, 16 Plus, 16e, iPhone 15 and 14 models | $99 | $0 |
| iPhone X to iPhone 13 | $89 | $0 |
| iPhone SE and iPhone 8 | $69 | $0 |
| iPhone Duo | $229 | $0 |
Prices exclude tax, and Apple Authorized Service Providers can set their own fees. UK prices are different and are quoted in pounds on Apple’s UK repair page, so check your model there rather than converting these dollar figures. Apple guarantees its repairs for 90 days or the rest of your warranty, whichever is longer.
How to slow down battery wear
You can’t stop a lithium-ion battery from aging, but you can slow it. Apple’s main advice is to avoid heat and avoid sitting at 100% for long periods.
- Turn on a charge limit (iPhone 15 and later). Go to Settings > Battery > Charging and pick a limit between 80% and 100% in 5% steps, per Apple’s Charge Limit guide. The phone will still top up to 100% now and then to keep its estimates accurate.
- Leave Optimized Battery Charging on. It’s on by default and delays charging past 80% when it predicts you’ll be plugged in for a long time, such as overnight. It needs about 14 days to learn your routine.
- Keep it out of the heat. Apple specifically warns against charging or leaving your iPhone in hot places, including direct sun.
- Store it half charged. If a spare phone is going in a drawer for months, leave it around 50%.
If battery life suddenly drops after an iOS update, give it a few days before blaming the battery; we covered that pattern in our iOS 27 battery drain explainer.
Our verdict
Check Settings > Battery > Battery Health once or twice a year, and always before buying a used iPhone or paying for AppleCare. Above 85%, there’s nothing to do. Between 80% and 85%, start planning. Below 80%, replace the battery: it’s free with AppleCare and $69–$129 at Apple in the US otherwise, which is far cheaper than a new phone. On a used iPhone 15 or later, look at the cycle count and General > About too, because they tell you how hard the battery has worked and whether it’s genuine.
FAQ
How do I check my iPhone battery health?
Open Settings, tap Battery, then tap Battery Health (iPhone 15 and later) or Battery Health & Charging (iPhone 14 and earlier). The Maximum Capacity percentage shows how much charge the battery holds compared with when it was new.
What is a good battery health percentage for an iPhone?
Anything above 85% is healthy. Apple considers a battery worn below 80%, which is also when AppleCare covers a free replacement.
How do I see the battery cycle count on my iPhone?
On iPhone 15 and later with iOS 17.4 or newer, the cycle count appears in Settings > Battery > Battery Health. iPhone 14 and older models don’t show a cycle count in Settings.
Can I check iPhone battery health without setting it up?
Apple doesn’t offer an official way to do that. The Battery Health screen is in Settings, so the iPhone needs to be activated first; when buying used, ask the seller to show you the screen before paying.
Does a factory reset change iPhone battery health?
No. Battery health reflects the battery’s actual condition, so a reset doesn’t raise or lower it. You’ll see the same figure in Settings after setting the phone up again.
How much does Apple charge to replace an iPhone battery?
In the US, Apple’s out-of-warranty battery service costs about $69 to $129 depending on the model, and $229 for iPhone Duo. With AppleCare it’s free once Maximum Capacity is below 80%.
