Where to find your battery health on iPhone
Your iPhone stores battery health information in the Settings app under Battery, then Battery Health & Charging. Open Settings, tap Battery, then tap Battery Health & Charging — you'll see a percentage labeled "Maximum Capacity" and a condition status below it. That percentage tells you how much charge your battery can hold compared to when it was new. A new iPhone shows 100%; as the battery ages, this number drops.
The condition status appears as a word or short phrase: "Normal" means your battery is working as expected, while "Service Recommended" or "Service Battery" means Apple detected a problem. If you see "Unknown" or "Unable to Determine," your iPhone cannot read the battery properly — this sometimes happens after a repair by someone other than Apple.
Key Takeaways
- Maximum Capacity shows what percentage of a full charge your battery can hold right now, compared to when it was brand new.
- A battery at 80% capacity or higher is considered normal wear; below 80% means the battery is aging faster than typical.
- The Condition status tells you whether Apple detected a hardware problem, separate from normal aging.
- iPhones with a battery below 80% capacity can still work, but you may notice shorter battery life between charges.
What the Maximum Capacity percentage really means
Maximum Capacity is not the same as your current battery level. If your Maximum Capacity is 85%, that means your battery can now hold 85% of the charge it held when new — but when you charge it fully today, you're charging it to 100% of that 85%. You won't see a "15% missing" notification; instead, your phone will die sooner than it did a year ago, even after a full charge.
All rechargeable batteries lose capacity over time. Lithium batteries, which power iPhones, degrade with every charge cycle. A charge cycle means using 100% of your battery's capacity — this could be one full drain and recharge, or two half-drains and recharges. After roughly 500 charge cycles, most iPhone batteries drop to around 80% capacity. After 1,000 cycles, they typically fall to 70% or lower.
Apple considers 80% capacity the threshold where you might notice a real difference in how long your phone lasts. Below that point, you'll probably need to charge more often. At 50% capacity or lower, the battery may not hold enough charge for a full day of normal use.
Understanding the Condition status
Normal means your battery is aging as expected and no hardware failure has been detected. This is the status you want to see, and it can appear at any capacity percentage — a two-year-old iPhone with 78% capacity can still show "Normal."
Service Recommended appears when Apple's diagnostics detect that your battery is degrading faster than normal, or that it's not holding charge reliably. Your phone will still work, but Apple is flagging that the battery may fail sooner than expected. You can continue using your iPhone, but a battery replacement would restore full capacity and reliability.
Service Battery means Apple has detected a significant problem — the battery may not charge properly, may drain rapidly, or may shut down unexpectedly even when it shows charge remaining. This status usually appears on older iPhones or those that have been through physical damage. Your phone needs a battery replacement to work reliably.
Unknown or Unable to Determine appears when your iPhone cannot read the battery's health data. This often happens if the battery was replaced by a repair shop that is not Apple or an Apple Authorized Service Provider, or if the battery itself is damaged. Apple's system cannot verify the battery's authenticity or condition, so it cannot report a status. Your phone may work fine, but you won't have reliable health information.
When to replace your iPhone battery
You don't have to replace your battery at any specific capacity percentage — it depends on how you use your phone. If you charge every night and use your phone moderately, a battery at 80% capacity may work fine for another year. If you're away from chargers all day, you might want a replacement at 85% capacity so you don't run out of power.
Replace your battery sooner if you see "Service Recommended" or "Service Battery" status, because these indicate a problem beyond normal aging. A battery with a hardware fault can fail suddenly, leaving you without a phone until it's replaced. If your Maximum Capacity is below 50%, you'll almost certainly notice the phone dying much faster than you expect, even with light use.
Apple offers battery replacement at its stores and through mail-in service. Apple Authorized Service Providers can also replace batteries. Costs vary by iPhone model, but typically range from $50 to $100 for out-of-warranty replacement. If your iPhone is still under warranty or AppleCare+, battery replacement may be covered if the capacity has dropped below 80% due to a defect rather than normal use.
How to extend your battery's lifespan
Charge your phone to 100% less often if you can. Keeping your battery between 20% and 80% charge slows degradation. If you plug in every night and charge to 100%, your battery will age faster than if you charge to 80% most days and only top up to 100% occasionally. iPhones running iOS 13 or later have an Optimized Battery Charging feature that learns your charging habits and holds the charge at 80% until you need it — this can help extend battery life.
Avoid heat. Lithium batteries degrade faster in hot conditions. Don't leave your iPhone in direct sunlight, in a hot car, or near a heat source for long periods. If your phone gets hot during normal use, it may be running a process that's draining the battery faster than usual — check which apps are using the most battery in Settings > Battery > Battery Usage.
Use the right charger. Apple's official chargers and certified third-party chargers are designed to charge safely. Very cheap chargers or damaged cables can deliver inconsistent power, which stresses the battery. If your cable is frayed or your charger feels hot, replace it.
Checking battery health on older iPhone models
The Battery Health & Charging screen is available on iPhone 6 and later, running iOS 11.3 or newer. If you have an older iPhone or an older version of iOS, you won't see this information in Settings. You can update your iPhone to the latest iOS version by going to Settings > General > Software Update.
If your iPhone is too old to support the Battery Health feature, you can still see which apps are using the most battery power by going to Settings > Battery > Battery Usage. This won't tell you the overall health of the battery, but it will show you whether a particular app is draining power unusually fast.
Frequently Asked Questions
Is 80% battery capacity bad?
No. Eighty percent is the point where Apple says you might start to notice shorter battery life, but many people use phones at 80% capacity without problems. It depends on your daily routine — if you charge every night, 80% capacity may work fine. If you're away from chargers all day, you might want to replace the battery sooner.
Can I improve my battery health percentage?
No. Maximum Capacity only goes down as the battery ages; it cannot be restored by software updates, settings changes, or charging habits. Only a physical battery replacement will restore the capacity to 100%. However, you can slow the rate at which capacity drops by avoiding heat and not charging to 100% every day.
Why does my battery health show "Unknown"?
This usually means your battery was replaced by a repair shop that is not Apple or an Apple Authorized Service Provider. Apple's system cannot verify the battery's authenticity, so it cannot report health information. Your phone may work fine, but you won't have reliable battery diagnostics. Contact Apple or an authorized provider if you want a verified replacement.
Does battery health affect my phone's speed?
Yes, but only in specific cases. If your battery capacity drops very low (usually below 50%), iOS may slow down your processor to prevent the phone from shutting down unexpectedly. This is called performance management. Once you replace the battery, the phone returns to normal speed. You can check whether performance management is active in Settings > Battery > Battery Health & Charging.
How often should I check my battery health?
Once every few months is enough for most people. If you notice your phone dying much faster than usual, check the battery health to see whether the battery is the problem or whether an app is draining power. There's no benefit to checking more often — battery capacity drops slowly over weeks and months, not days.