The continued emphasis on battery life is one reason why fast chargers are so ubiquitous now, at least for high-end devices. The fastest and most powerful of all are from premium phones like theand . If the battery is about to run out before the end of the day, fast charging with your lightning fast charger is the best alternative. Especially with fast charging, a 10-minute charge time can make the difference between going into a frugal power-saving mode and completely losing power before you get home.
But now that fast charging is so readily available for phones, we have questions: Can a high-capacity charger damage your phone's battery in the short term? Can it decrease your phone's energy storage capacity over time? And what causes unnecessary wear on your phone's battery anyway?
To get the answers, we spoke to several battery researchers and engineers about the effects of fast charging on your phone's battery life. This is what we have learned.
Your Phone Battery Does Not Change Quickly
All mobile phones – and most personal electronics and electric vehicles – use lithium ion (li-ion) rechargeable batteries. It's hard to make batteries that last longer because battery technology hasn't changed in decades. Instead, much of the recent advancements in battery life are thanks to power-saving features built into devices and by creating the software that manages charging and discharging more efficiently so you flow instead of slurp.
Unfortunately for mobile phones, the focus on extending battery life in general is on cars, satellites and your home power system, areas where industrial batteries should last much longer than the two or three year we expect from our mobile devices.
Another force that works against our phones is their battery size. Compared to an electric car battery, a phone's power source is minimal. For example, the Tesla 3's rechargeable battery has a battery capacity more than 4,000 times greater than the iPhone 11 Pro Max.
The math gets a bit complicated because phone batteries are measured in milliamp hours, while electric vehicle batteries are measured in watt hours. But it is possible to draw equivalents. For example, the Pixel 4 has a 2,800 mAh battery (or 10.6 Wh) and the iPhone 11 Pro Max is said to come with a 3,969 mAh battery (15.04 Wh). Meanwhile, the Chevy Volt uses an 18,400 Wh battery, and a mid-range Tesla Model 3 sports a 62,000 Wh battery.
That's important because the bigger a battery is, the more battery-saving tricks there are to extend the life. For example, when you charge a battery, the voltage increases, putting it under voltage, especially during the last 20% of the charge. To avoid this stress, electric car manufacturers are allowed to charge new batteries to just 80%. Due to that greater battery capacity, the electric car can still travel an acceptable distance, while avoiding the voltage of higher voltages. This can double the total life of the car battery.
With larger phone batteries, you can charge all day long, but usually only 100% full. And while this allows the battery to last an acceptable time between charges, it's also more taxed by the higher voltage required to finish it.
Shortly before a major breakthrough in battery technology, improvements will be made to our phone batteries by making the devices more energy efficient overall. (Here's a more detailed look at what's holding back the battery revolution.)
Fast charging won't damage your battery
A conventional charger has a power rating of 5 to 10 watts. A faster charger can improve that up to eight times. For example, the iPhone 11 Pro and Pro Max come with an 18-watt fast charger, the Galaxy Note 10 and Note 10 Plus have 25-watt chargers in their boxes. Samsung will sell you an extra fast 45 watt charger for $ 50.
Unless there is a technical glitch with your battery or charger electronics, using a fast charger will not damage your phone's battery in the long run.  This is why. Fast charge batteries operate in two stages. The first phase creates a voltage spike on the empty or almost empty battery. This gives you that blazing fast charge of 50 to 70% in the first 10, 15 or 30 minutes. That's because batteries can quickly take charge during the initial charge phase without any major long-term negative consequences for their health.
For example, Samsung promises that its 45-watt charger can be charged from zero to 70% in half an hour. Apple says the fast charger that comes with its iPhone 11 Pro can be charged up to 50% in 30 minutes.
Do you know what it seems to take as long to charge the last 20 or 30% of the battery as it takes to charge the first 70 or 80%? The latter part is the second charging phase, where phone manufacturers have to slow down the charge speed and manage it carefully, otherwise the charging process can actually damage the battery.
Arthur Shi, a finishing engineer at the do-it-yourself repair site iFixit, suggests presenting a battery as a sponge. When you first pour water on a dry sponge, it quickly absorbs liquid. For a battery, this is the fast charge phase.
As you continue to pour the increasingly wet sponge at the same rate, the liquid will bead on the surface as it struggles to pull into the saturated sponge. For a battery, this unabsorbed charge can lead to shorts and other issues that can potentially damage the battery.
Damage is rare if everything is properly managed inside. A battery's battery management system closely follows the two charging stages and decreases the charging rate during the second stage to give the battery time to take charge and avoid problems, so it can take up to 10 minutes to reach the last few percentage points.
The case of the tragically exploding battery of the Samsung Galaxy Note 7 was the result of design flaws in the battery rather than the battery management techniques of the phone software.
You can't overcharge your phone's battery
Overcharging caused phone owners to fear. The fear was that the constant charging of a phone could charge a battery above its capacity, making the battery unstable, which could affect the overall battery life or build up too much internal heat and cause the battery to burst or break fire flies.
However, according to the experts we spoke to, a battery management system is designed to cut off the electrical charge once a battery reaches 100% before it can be overcharged.
"Unless something goes wrong with the battery circuit, you can't overcharge a modern phone," said Venkat Srinivasan, a battery researcher at Argonne National Laboratory and director of the Argonne Collaborative Center for Energy Storage Science. "They have built-in security to prevent that exactly."
Remember, however, you can power a battery while charging 100%, as described above. (That's why electronic vehicle manufacturers cut off new battery charging by about 80%.)
Apple cleverly addresses this issue in iPhone software iOS 13 that charges your iPhone's battery to 100 % without causing long-term damage.
If you often keep your iPhone plugged in during the day or while sleeping, you can enable a battery setting for iOS 13 calledthat monitors your charging schedule and maintains your iPhone's battery charge. at 80%, keeping it out of the stress zone. Then the charge will be 100% charged just before you disconnect your phone regularly. This works best for those with a regular charging pattern.
For a manual approach, you can also unplug your phone when it's 80% charged, but the downside is that you may miss extra hours of use that you would get from a fully charged phone.
You should not drain your battery to zero
You may want to drain your phone from time to time to have the battery recalibrate the charge status. But that's not such a problem with modern phone batteries.
In fact, discharging a battery all the way down can lead to chemical reactions that can shorten the life of a battery over time. To prevent a full discharge, a battery management system includes safety features that shut off a phone when it reaches an energy level that is safely above empty. You don't think you've reached zero until you see that last low battery warning.
If you want to take a more active hand in the health of your battery, connect your phone when the battery level drops by about 30%, above the stressfully low battery levels
High temperatures can damage your battery
Heat is a real enemy of your battery. High temperatures are known to shorten battery life over time.
You want to keep your phone out of direct sunlight, away from window sills and away from your car dashboard to avoid overheating, which can make the battery less efficient over time. In extreme cases, an overheated battery can explode.
Temperatures of up to 86 degrees Fahrenheit (30C) can reduce the effectiveness of a battery, said Isidor Buchmann, founder and CEO of battery technology company Cadex Electronics and its battery university educational website.
Does this mean you want to keep your phone in an ice box? No. But as much as possible, keep it away from high temperatures. If you're out in the sun for a long time, put a towel or T-shirt over it or put it in a bag with your cool water bottle. The idea is to prevent the internal temperature of the phone from rising.
Mismatched chargers and cables will not damage your battery
Unless you use counterfeit or damaged chargers and cables, combining and matching cables and chargers will not damage your battery. However, you may not be able to charge as quickly as possible, such as when using the devices that came with your device.
Some phones, such as those from Huawei and OnePlus, use a proprietary charging design – with part of the circuit responsible for fast charging built into the charger. To take full advantage of the device's own fast charging, use the compatible charger.
Other phone manufacturers, such as Samsung and Apple, adhere to the industry standard fast charging rules and let you charge effectively quickly with a variety of compatible cables and chargers.
The safest bet is to use the chargers and cables that come in the box, because when mixing and matching chargers and cables with your phone, the device can use the lowest possible charging speed by default.
How else can I save? the battery of my phone?
To get more out of your battery, you can use the usual energy-saving tricks to save the battery, such as dimming the brightness of your screen, turning off Wi-Fi and Bluetooth when not in use, limiting the use of background data monitor via settings and apps that use GPS.
But the truth is, no matter how careful we are, our phone batteries only last so long. The trick is to get as many months out of our battery as possible without constantly fearing the charge.