IPhone Battery Stages

9 truths about the iPhone battery

Does the iPhone’s fast charger damage the battery over time? How to extend battery life? Experts reveal some truths about the iPhone’s battery and dispel common myths among users.


One of the most controversial issues in the technology community is about the iPhone battery. How can, after so many years, we still need to plug the device into the outlet every day?

In addition, several myths are created about the use and preservation of the battery. Does leaving charging all night overload the battery? And does fast charging damage its life? And if you don’t use Apple cables, is it worse?

Some experts talk about these myths and shed some light on the iPhone battery.



Truth 1 Fast charging does not damage the battery

The pressure from all users to have a better battery is constant for all smartphone manufacturers. With that, it was more than natural to popularize the fast loading between devices.

On the iPhone, it was incorporated with the iPhones 8 and X in 2017, and continues today.

Many users believe that this fast loading harms battery health device physics. But according to experts, this is not true.

Until 2019, the standard iPhone charger that came in the box was a 5W. On the iPhone 11 Pro, Apple started adding more powerful 18W chargers that charge much faster.

Fast-charging batteries work in two stages. The first applies a large amount of voltage to the battery that is empty or almost empty, which provides an incredible 50% charge in the first 30 minutes. This is because, during the first phase of charging, batteries can quickly absorb a charge, without major negative effects on long-term health.

IPhone Battery Stages

This first phase lasts up to 80% of the battery. From there, the second stage begins, in which the load becomes slower, since it is in this part that an overload could damage the components.

IOS manages the entire process. It closely monitors the two phases of the charge and slows down the charging speed during the second stage to allow the battery time to absorb the charge and avoid problems, which is why it may take longer to get those last percentage points.

So, no, the fast charge does not damage the battery life, because in the critical phase when an overload could be harmful, the system takes care of providing a slower charge.


Truth 2 Leaving the iPhone charged overnight does not damage the battery

Many are afraid that, leaving the iPhone charging all night, this could overcharge the battery when it reaches 100% and remains connected.

But rest assured, because that’s not what happens.

According to experts, the iOS management system is designed to turn off the electrical charge when the battery reaches 100%, before it can overcharge.

In iOS 13, Apple further reinforced this caution. To lessen the risk of overload, it included a function of Optimized Battery Charging, which interrupts the charge at 80% and resumes as close to the user as needed. This calculation is done with machine learning based on the owner’s habits.

Optimized Battery Charging

Of course, this function works best for users who have a constant charging habit, such as always waking up at the same time or having the habit of charging during the day, at a specific time.



Truth 3 You must not let the battery reach 0%

Another myth that is widely publicized is one that says that, from time to time, it is important to let the iPhone shut down by itself without charge, for “recalibrate the battery“. Do not do it!

This myth originated in the old cell phones. But after lithium-ion batteries began to be used, it never had to be done again.

In fact, what happens now is the opposite: completely discharging a battery can cause chemical reactions that, over time, can reduce battery life.

So much so that iOS intelligently turns the device off before the charge really runs out completely, just to try to protect the integrity of the device. But it is important to never leave an iPhone uncharged for many hours, as this can damage the battery.

If you really care about protecting the health of your battery, the ideal is to always try to recharge when the battery level decreases by around 30%, well above the low levels that can cause damage.


Truth 4 High temperatures can damage your battery

You probably already know, but it doesn’t hurt to repeat: at temperatures that exceed 35ºC, the battery can suffer serious damage to your health and decrease its effectiveness.

Since we live in a country that in certain regions reaches these climatic levels during the summer, there is little care. But even in colder periods, carelessness can put your device at risk.

For example, leaving the iPhone on the dashboard of the car, or on a beach in the scorching sun. Anything that can cause the device to overheat can make the battery less efficient. And in extreme cases there is even a risk of explosion.

So, a basic rule: keep your iPhone away from high temperatures.

IPhone temperature


Truth 5 Chargers and cables from other brands do not damage your battery

Apple suggests using only cables and chargers made by Apple. However, the price is twice that of other options on the market.

But don’t worry: mixing and matching cables and chargers will not harm your battery. However, they cannot be faked, must be accessories approved by a regulatory agency, such as Anatel, for example, or even Apple itself.

So, using USB chargers from other brands, such as Samsung or Motorola, or purchased from trusted stores, do not cause any problems, as they are built with safety devices that do not damage the device.

Same thing with Lightning cables. If they have the MFi seal, were approved by Apple and also perfectly fulfill the function.

It is always good to remember that loader and cable are two different accessories. It is common for some people to call the cable or both together “charger”, but this is not correct.


Truth 6 Closing open applications doesn’t save battery

There is a myth of multitasking: the more applications that are open at the same time on the system, the more battery is consumed. This is quite true on other systems, but on iOS the management of multitasking is different. Applications are in a “frozen” state when in the background, which greatly reduces energy consumption.

Because of this myth coming from other systems, many people are in the habit of always closing applications that they do not use. But iOS multitasking has an advantage thought by Apple engineers: saving application data in RAM, speeding up their resumption when they are used again.

If you completely close an application that you are going to use soon after, this will cause it to have to be completely reloaded, which consumes more processing and, more battery. So, just close the apps that you really won’t be using for a long time, to not make the processor work folded.

The only exception that can be made is regarding GPS applications, which constantly use location even with the app in the background. In this case, they end up sucking the battery even if they are not used, so it is advisable that if you stopped using it at that time of day, it is best to close it so as not to waste the battery for nothing.



Truth 7 Your battery degrades with each passing month

As much as you take all the care in the world, the fact is that your physical battery will degrade over time. It’s a fact.

With each loading cycle, it loses a little bit of its useful life. So, don’t want a cell phone that is already 3 years old to have a battery with the same performance as when it was purchased. This is physically and chemically impossible. And it’s normal! Don’t blame yourself for that, because this is how things were made to work.

As lithium-ion batteries age chemically, the ability to hold a charge decreases, resulting in shorter periods between device charges. This can be called maximum battery capacity, which is a measure of load capacity compared to when it was new.

In iOS 11.3 the company has incorporated in all iPhones a function that shows the Battery Health. And when you have less than 80%, she advises to change, so as not to reduce the performance of the device.

But while this function is a useful reference, try not to go crazy if you notice that your battery’s health numbers are decreasing. This is just a reference and will only be a problem when the battery really has strange faults. There are many iPhone 11 users who are experiencing this, but so far this has not become an official problem:


Truth 8 Battery technology hasn’t changed in a long time

As much as we want Apple to launch an iPhone each year with a battery that lasts longer than previous models, the fact is that lithium-ion battery technology it’s been the same for decades. It is stagnant.

From 1995 to 2007, the capacity to store energy has not even increased by 30%. And the prospect is that the situation will not improve much by 2021.

If manufacturers see improvements in battery life all year without increasing the physical size of the battery, it is because there has been a lot of work to optimize the software, in addition to adopting new components that consume less energy, such as microprocessors and the OLED screen.

Currently, the focus on developing new batteries is more focused on electric cars and satellites than on cell phones, which are much smaller.

The battery for a Tesla 3 car has a battery capacity more than 4,000 times that of the iPhone 11 Pro Max.

This matters because the bigger the battery, the more tricks can be done to extend its life. For example, when you charge a battery, the voltage increases, putting you under stress, especially during the last 20% of the charge. To avoid this stress, electric car makers can only charge new batteries by 80%. Due to the greater capacity of the battery, the electric car can still travel an acceptable distance, avoiding the stress of higher voltages. This can double the total battery life of the car.

So, unless we see in the coming years the advancement of some new technology in this area, we will not have major developments in the durations of cell batteries.


Truth 9 You can charge the battery at any time

Lithium ion batteries operate on charge cycles. For this reason, there are those who believe that there are certain times to recharge the battery. Or that charging when it is at 40% and not leaving up to 100% will not complete the cycle.

Don’t worry about that. The battery cycles are counted from 0 to 100%, even if you start in the middle and do not finish charging it.

A charge cycle ends when you use (discharge) an amount equivalent to 100% of the battery’s capacity, but not necessarily a charge. For example, you can use 75% of the battery’s capacity in a day, then give a full charge overnight. If you use 25% the next day, you will have discharged 100%, and the two days will be equivalent to a charge cycle.

IPhone battery cycle

Thus, a complete cycle can take several days. And as we explained earlier in this text, the battery capacity decreases a little with each full charge cycle.

Are you curious to know how many charge cycles your iPhone already has? We made a tutorial explaining how to know:


How to save battery on iPhone

Knowing these truths and demystifying ineffective ideas will already help you to better treat your iPhone battery and make it last longer.

The old and well-known iPhone battery-saving tips still hold. We even made an article about it: