When your iPhone tells you that the battery is around 79%, it's normal to panic. This warning does not mean that the mobile is in danger., but has reached a point of wear and tear where it is worth considering a change for regain autonomy and performance.
In fact, your iPhone can continue working like this for as long as you want. The important thing is to understand what that percentage implies., how it will affect your daily life, and what real options you have to improve the experience: from recalibrating your health readings to replacing the battery at an official service center.
What it means to be at 79% battery health
That 79% is the “maximum capacity” that iOS shows in Settings > Battery > Battery Health & Charging. Indicates how much charge your battery can store compared to when it was newIf before it filled “100 units”, now it fills 79 in the same 100% bar.
Why doesn't a warning appear at 80% of cases, but at 79% of cases it does? Apple internally defines this threshold for recommending replacement. It is not a technical cut that makes using the mobile phone dangerous., is a reference to guide the decision to change if you notice short autonomy, blackouts or irregular performance.
At that point, iOS may suggest you go to an official supplier to replace the battery and, in fact, It will list nearby Apple Stores and SATs. (such as K‑tuin or MediaMarkt) to make the replacement with original components.
Is it dangerous to stick with 79%? Benefits of changing it versus waiting
Continuing at 79% is not risky. The phone is not going to be damaged by this.; what you'll notice is less usage time between charges and, at times, less stable performance peaks.
However, changing the battery brings clear advantages: more daily autonomy (that “getting home at 1%” becomes a relaxed end to the day), better sustained performance (power supply to CPU and GPU is stabilized) and less temperature in demanding tasks, something key in summer.
In addition, a new cell degrades more slowly by working at lower heat. This helps to take care of the rest of the components., because the entire system suffers less thermal and electrical stress in daily use.
If you plan to keep your iPhone for another 1–2 years, replacing it makes sense. If you prefer to squeeze to the end and don't mind loading more often, you can continue without any problem until the performance becomes uncomfortable for you.
How iPhone lithium-ion batteries work
The iPhone uses lithium-ion batteries because they charge quickly, are lightweight, and store a lot of energy per volume. They are ideal for mobile devices, but they have a “chemical age”: Over time and with charging cycles, they lose capacity and instantaneous maximum power.
Two key concepts: “battery life” (how long you can stay on between charges) and “battery lifespan” (how long until it needs replacing). Both depend on your habits, cycles and temperatureStoring your iPhone at medium charge for long periods of time and avoiding heat helps prolong its lifespan.
Internal impedance increases with age, cold, and very low loads. The higher the impedance, the more the voltage drops when the system requests power.If the voltage drops too low, iOS cuts off to protect the circuits—that's the unexpected blackout that sometimes occurs with older batteries.
Performance Management in iOS: What It Does and What It Doesn't
To avoid blackouts, iOS applies dynamic performance management that smooths out consumption peaks on the CPU and GPU. This distributes the load and prevents sudden voltage drops when the battery is cold, weak, or aging.
This feature first came to iPhone 6/6s/SE/7 and then to iPhone 8/8 Plus/X (iOS 12.1) and XS/XS Max/XR (iOS 13.1), and is still present in recent generations. iPhone 8 and later better estimate needs and capacity, so its effects are less noticeable.
When management is intense, you may notice: apps that take a little longer to open, scrolling with fewer frames, brightness somewhat dimmed (you can turn it back up), speaker volume up to 3 dB lower, gradual fps drop in some apps, flash disabling in extreme cases, and apps reloading in the background when returning to them.
There are areas that it does not touch: Call and data quality, photos/videos, GPS and location, sensors (gyroscope, accelerometer, barometer), and Apple Pay. That is, it prioritizes keeping the phone running without compromising on the essentials.
iOS 11.3 and later continually checks how much management is needed and lowers the level if the battery allows; if another outage occurs, it increases again. All iPhones also have basic management that cannot be disabled. for thermal and voltage safety.
How to check health and understand iOS messages
Go to Settings > Battery > Battery Health & Charging. There you'll see Maximum capacity (percentage with respect to new) and the peak performance capacity, with possible warnings if the system has applied management due to a previous blackout.
On some models, if iOS enables this management, a switch appears to disable it. You can do it, but if a blackout occurs again, the system will reactivate it to protect itself.
Please note that when you first get your phone, it may not be exactly 100% accurate due to the time since manufacturing. iOS 14.5 automatically recalibrates the estimate on iPhone 11, 11 Pro, and 11 Pro Max to correct inaccurate readings.
When is it “normal” to reach 80% and what happens below?
As a guide, after about 6 months you could see around 95%. A reasonable 85–90% per year is, and after two years, moving close to 80%.
If you drop below 80%, you will notice more recharges per day and, in some cases, more contained power peaks. It can also increase the likelihood of shutdowns if it's cold or you run out of battery.
Apple designs batteries to retain 80% of their capacity under ideal conditions after 500 complete cycles on iPhone 14 and earlier, and after 1000 cycles on iPhone 15The actual figure depends on your usage and charging habits.
Signs of wear and quick decision guide
Beyond the percentage, look at the symptoms: unexpected power outages, slower apps at peak loads, the speaker sounds a little quieter and, of course, autonomy that no longer lasts your day.
Guideline by ranges: 100–90%: good condition, you don't need to do anything. 89–85%: light wear, review your habits if you notice declines. 84–80%: moderate wear, you might start to notice fewer hours. <80%: advanced wear, consider changing if it affects your use.
How to force a better percentage reading (recalibration)
Sometimes health data may not accurately reflect reality due to iOS's estimation. You can “give more information” to the system with a small process of home recalibration.
First option: Drain the battery until the iPhone turns off by itself. Charge it in one go up to 100% and leave it plugged in for a while longer. Repeat the cycle at least three times in the coming days.
Second option: complete restoration from computer. On Mac with Finder (Catalina or later) or on PC/Mac with iTunes (Mojave or earlier), do “Restore iPhone” and set it up as new, without loading a backup, to avoid dragging data that could confuse the estimate.
Important: These methods do not “cure” the battery, they only fine-tune the reading. Chemistry is not regenerated with software, but sometimes you will see the figure slightly rise or fall from its actual value.
Habits that extend battery life
Temperature is the great enemy. Avoid charging in the sun or in very hot environments to and don't play demanding titles while charging: you increase consumption and increase heat, the perfect combination to accelerate degradation.
Better partial and frequent loads. The technique reduces stress by 20–80%Start charging around 20% and don't always aim for 100%. It's fine if you fill it up completely sometimes, but don't make it a daily habit.
Leave it charging overnight? There are nuances here. iOS manages charging well and can learn your routines to pause at 80% and complete before you wake up, which makes it reasonable to leave it plugged in. Other guides prefer to avoid this if possible, to minimize the time at 100% and residual heat.
If you are going to store it for weeks, leave it with a medium charge. Store at 50% and in a cool place minimizes aging. And if it feels warm, remove the case while charging.
Small tweaks that help: lower the brightness a little, disable unnecessary vibrations, and limit background updates for apps you don't use. These changes, when combined, are noticeable.
How to view health and status from Settings, step by step
- Open Settings.
- Enter Battery.
- Tap Battery Health & Charging.
You will see maximum capacity and performance messages. if iOS has implemented blackout management.
If a service alert appears, don't panic: It just means that the cell no longer performs like new. and that a replacement will give you back autonomy and stability.
Where to change the battery and how much does it cost?
My recommendation is to go to Apple or an official SAT. This way you ensure original parts and correct calibration.. Apple Store and providers such as K‑tuin or MediaMarkt provide official service.
Indicative prices for battery replacement: iPhone 16 Pro/Pro Max: €135. iPhone 16/16 Plus, 15/15 Plus, 14/14 Plus: € 109. iPhone SE (3rd gen): € 79Always check the updated price before making an appointment.
With AppleCare+ active, replacement is at no additional cost if capacity drops below 80% (or physical damage), with an approximate monthly subscription: iPhone 16 Pro/Pro Max €14,99/month; 16 Plus/15 Plus/14 Plus €13,49/month; 16/15/14 €11,49/month; SE (3rd gen) €7,49/month.
Quick FAQ
How many cycles do they last? iPhone 14 and earlier: 500 cycles up to 80% under ideal conditions; iPhone 15: 1000 cycles. Remember that cycles are cumulative (two 50% charges equal one).
Why does health sometimes drop suddenly? The estimate is based on algorithms and can be adjusted after upgrades, usage changes, extreme cold, or recalibration.
Can you "improve" your health without changing your battery? No, but you can. fine-tune the reading with full discharge-charge and clean restoration, and take care of habits so that it goes down more slowly.
What won't change in performance management? Calls, data, camera, GPS, sensors and Apple Pay will remain the same, although you will see the power peak smoothed in heavy applications.
When to make the decision to replace
If your daily routine is no longer complete without an outlet, if you experience power outages in the cold, or if performance frustrates you, don't hesitate: A battery change restores freshness to the iPhone for a fraction of the cost of a new mobile phone.
If you still complete the day and don't notice any problems, you can hold on. Even at 79% you can continue without risk, knowing that you will recharge more and that iOS will protect the system by limiting peaks when necessary.
The key is how you use your phone and how much you value battery life and fluidity. The 79% threshold is a guideline, not an order: decide by feeling and, if in doubt, go for a diagnosis at an official SAT.
Given the 79% warning, understanding what iOS measures, how it handles spikes, and what habits protect your cell phone puts you in the driver's seat. Between recalibrating, adjusting customs and replacing in an official service, you have room to give your iPhone back hours of use and stability without any problems.
