The iPhone features remarkable battery life, however, not every user experiences peak performance. It is essential to calibrate the lithium-ion battery periodically. This article details the process for maintaining your iPhone’s battery, which will ensure long-lasting battery life. This method also applies to the iPad and iPod Touch, as well as any other device with a lithium-ion battery.
Battery calibration accomplishes two things: it conditions the battery and helps the software calculate the range of battery life. One should calibrate the battery once a month and after every major iOS upgrade. If you upgrade iOS and notice diminished battery life, try calibrating the battery before anything else.
Periodically draining and recharging the battery keeps the flow of ions moving in the battery. The material properties of lithium-ion batteries require constant usage to maintain peak performance. For this reason, Apple recommends discharging and recharging the battery once a month.
The amount of charge available in the battery is calculated by iOS. With every upgrade, new features are added, some of which affect battery life. Apple’s engineers often improve some aspects of battery life, while also introducing battery-intensive features, such as background updates. Allowing the battery to fully drain and recharge calibrates iOS to detect the full range of battery life. Some people are skeptical of this theory, and since few know the inner workings of iOS, it may sound superstitious. Research and experience have proven otherwise. I have no doubt that calibrating the battery after an iOS upgrade will improve battery life.
How To Calibrate the Battery
The first step is to drain the battery completely. This can be accomplished with normal use, but sometimes this may not be an option. After all, you don’t want to head off to work with 2% battery life left. Sometimes that 2% can last a few hours. It’s best to drain the battery when you can do without your device for several hours, perhaps before bedtime. To expedite battery drainage, turn on the flashlight, turn up the brightness, and play a video, preferably streaming over the Internet.
Once your device powers off due to insufficient battery charge, it’s best to leave it for some time. If possible, leave it overnight and don’t charge it until the following morning. This is not always an option, and if it’s too inconvenient, skip this step. Allowing the device to sit overnight will further drain the battery. You may notice that even when your iPhone runs out of juice and powers down, when you immediately plug it back in, you will see it at 2-3% charge. This is partly due to the fact that some battery life was remaining when it powered down. To keep your data safe, iOS has to power down before the battery is fully drained. Otherwise, it would shut off without being able to save its state to secondary storage.
Next, plug your iPhone into the charger. Keep it in the charger until it’s at least 100% charged. If possible, keep it in the charger longer. According to Apple, 100% means that you will get the expected battery life, but the device can charge beyond this. Keeping the device in the charger after it reaches 100% will ensure it is fully charged. Two additional hours should do it.
It is best to charge your iPhone when it is off. After you plug in the charger, your iPhone will automatically start up in a few minutes. When it is back online, simply hold down the sleep/wake button and slide your finger over the off switch. Your iPhone will charge faster when it is off. It will also generate less heat, which will extend overall battery life.
If you turn your iPhone off to charge, make sure to estimate how long it will take to charge beyond 100%. Five hours is a safe bet for an iPhone 6 or 6 Plus. My iPhone 6 will charge to 100% in three hours, but the extra two hours will ensure that it is fully charged — beyond 100%.
Now that your device is fully charged, you should reset it. This is done by holding down the sleep/wake button (on the top of the device) and home button, until the Apple logo appears. In iOS 7, if you do this from the lock screen, your device will just go blank. This scared me at first. I thought I had bricked my iPhone. Just remove your fingers from both buttons and then hold down the sleep/wake button until you see the Apple logo. Your device will boot up and is now reset.
Step By Step Battery Calibration
The following process is what I consider to be the gold standard of iPhone battery calibration. For some, it might not be possible to follow all of these steps. If you are an on-call professional or hopelessly addicted to your iPhone, you might not be able to turn off your iPhone overnight or even for a few hours. At the bare minimum, you need to drain the battery until the device shuts off, charge your iPhone to 100%, and reset it by holding down the sleep/wake and home buttons until you see the Apple logo.
1. Use your iPhone until it shuts off automatically. If it is near 0% battery life and you want to drain it faster, turn on the flashlight, turn up screen brightness all the way and play a video, preferably streaming from the Internet.
2. Let your iPhone sit overnight to drain the battery further.
3. Plug your iPhone in and wait for it to power up. Make sure to use the charger supplied by Apple or one that runs at the same wattage and amperage.
4. Hold down the sleep/wake button and swipe “slide to power off”.
5. Let your iPhone charge for at least 5 hours. The charge progress indicator is not displayed while your iPhone is turned off.
6. With the charging cable still connected, press the sleep/wake button for about a second to start up your iPhone.
7. When the iPhone has booted up, hold down the sleep/wake and home buttons until you see the Apple logo.
8. When your iPhone is back online, remove the charging cable.
Make Your iPhone’s Battery Last Longer
A lot of people visit this site because their iPhone’s battery is shot. Calibration can help in some cases, but it is not a panacea. If calibration doesn’t improve your iPhone’s battery life, it may be time to replace the battery. Fortunately, you can prolong the lifespan of your new battery by following a few tips. For more information, please read “How To Extend iPhone Battery Lifespan”.
Many users are skeptical of this process and feel it is superstitious. I hope I have shed light on the reasons why you should calibrate your iPhone battery. If you doubt this article, take screenshots of your battery life (Settings > General > Usage) before and after conditioning the battery. I have found this process to work. Of course, your battery may drain at different rates depending on use. For more information and tips about lithium-ion batteries, please read this article. Also, make sure to check out “iOS 7 Battery Life Tips” for more information on how to preserve battery life with iOS 7.