How to charge an iPhone properly
6 min read
iPhones are remarkable devices, but they lose their lustre once the battery runs dry. That’s why it’s important to look after the cell inside and ensure that you always charge it properly.
In this article we explain the steps you need to take if you want your iPhone to last till the late hours each day and keep doing so for as many years as possible.
How to charge an iPhone with a cable
The fastest way to charge an iPhone is using a cable. Until the iPhone 15, this meant using a USB to Lightning cable. From the iPhone 15 on, you need a USB-C to USB-C cable.
But it’s not quite as easy as that. For the fastest charge, that Lightning cable needs to connect to a USB-C charger so you need a USB-C to Lightning cable and not an old USB-A to Lightning cable.
While Apple states that a 20W charger can fast-charge an iPhone, newer iPhone models will charge faster if you use a 30W or faster charger.
Read about the best Lightning cables and the best USB-C to USB-C cables for iPhone.
How to wirelessly charge an iPhone
From the iPhone 8 on, you can charge wirelessly. From iPhone 8 to iPhone 11, this used the Qi wireless charging standard. From iPhone 12, you can use Qi chargers or faster MagSafe chargers that clamp to your iPhone using a ring of hidden magnets for a more efficient fit and therefore faster wireless charging.
Qi chargers range in power from 5W to 15W; MagSafe chargers from 7.5 to 15W. Because of the magnetic fit MagSafe chargers will be faster even if at the same wattage as Qi, so got for a MagSafe charger if you can (and your iPhone is version 12 or later). Read our recommendations for the best MagSafe chargers and also the best MagSafe power banks.
The latest Qi2 chargers should match MagSafe on 15W charging speed; see What is Qi2 for more details.
How to charge an iPhone using a power bank
Portable power banks offer the ability to charge an iPhone on the go when you’re not near an outlet or don’t have time to sit for 15 minutes. They range from a few thousand milliamp hours to more than 15,000, which is enough to change an iPhone 15 Pro Max nearly three times. Most power banks need a separate charging cable that connects to the iPhone, though some have built-in cables that are stored somewhere inside the device. Some higher-end power banks have magnetic pads for charging wirelessly as well.
Using a power bank is simple. Make sure you charge it before you head out and then when you want to fill up your iPhone, use it as you would use a regular charger—either with a cable or wirelessly. Most power banks have LED lights to let you know how much charge is remaining.
You can learn more about MagSafe power banks and read our best picks in our roundup.
How to use the iPhone’s Charging Optimization settings
Inside the Battery tab in Settings, Apple has a Charging Optimization option that lets you turn on features to preserve battery wear over time and conserve energy. They are:
- Optimized Battery Charging: Your iPhone will learn from your daily charging and usage habits so it can limit charging to 80 percent until you need to use it.
- 80% Limit: Your iPhone will stop charging at 80 percent most days and only charge to 100 percent to “maintain battery state-of-charge estimates.”
- Clean Energy Charging: Your iPhone will attempt to charge when lower carbon-emission electricity is available in your area based on your daily usage habits.
You can turn on any of these options in Settings or opt for None, which will charge to 100% when you plug it in as normal.
How to choose the best iPhone charging accessories
There are two things to consider when shopping for new iPhone charging gear: the charger and the cable. The iPhone comes with an Apple USB-C cable that supports charging of up to 60 watts, more than enough to fast-charge any iPhone, but only USB 2 speeds (480Mbps) for data transfers. If you’re buying a second or replacement cable for charging, we recommend getting one that supports at least 5Gbps for data transfers.
You’ll also need a power adapter, and we recommend getting one that’s at least 30W for the fastest charging. If you don’t want to carry around multiple adapters, buy one that has two or more ports and can charge two devices at once (60W or higher will be best). Check out our roundup of the best USB-C power adapters for iPhone and MacBook for a good selection for any budget.
FAQ
Can I leave my phone charging overnight
Ever since smartphones arrived, the most common way of recharging them has been to plug them in when you go to bed, then disconnect them in the morning with a full charge to last the day.
This made a lot of sense when batteries took a long time to get up to full charge, as the eight hours in bed gave both the user and device time to recover from the previous day’s exertions.
But now, as the period it takes to charge a battery has dramatically reduced, it’s time to reconsider how you top up the tank.
iPhones use Lithium-ion batteries because, Apple states, they “charge faster, last longer, and have a higher power density for more battery life in a lighter package”. These are all fine features, but one thing that Li-On is not really keen on is being reduced to 0 percent and then back up to 100 percent each day.
Apple recommends, as do many others, that you try to keep an iPhone battery between 30 and 80 percent charged. Topping up to 100 percent isn’t optimal, although it won’t necessarily damage your battery, but letting it regularly run down to 0 percent can prematurely lead to a battery’s demise. There is an exception, as it’s considered good form to do a complete 0-100 percent charge about once a month, just to keep the battery in good shape.
For all other instances, though, the best practice is to top your battery up periodically during the day so that it stays in that sweet spot. Hopefully, this should keep the cell healthy for as long as possible. To make this easier to achieve we recommend keeping an extra charger at work or in your car so that you can pop the iPhone on to it when you see the battery beginning to fade.
There’s more on why you shouldn’t charge a phone overnight here.
Can I use any charger to charge my iPhone?
The generala dvice is that you should use the charger that came with your device. If you have an iPad, then the charger that came with it is also compatible and may actually get your iPhone up to a full tank quicker than its own charger.
But there are faster, smaller and cheaper chargers that beat Apple’s own. There are various third-party charger offerings on the Apple store itself, but, just for you, we have tested the best iPhone chargers to make your choices much easier.
Charging an iPhone via a cable is the speediest way to get back up to full power but wireless charging is often more convenient. From the iPhone 12 on, Apple has added a magnetic technology called MagSafe that makes wireless charging more efficient and therefore faster.
Avoid cheap knock-off products, as in some cases these have been known to damage devices. See our Are cheap iPhone chargers safe? feature for more details.
Does fast charging damage an iPhone?
No. So long as your iPhone has the Fast Charge capabilities (from the iPhone 8 and later) then the battery and iOS work together to ensure that it won’t overheat or cause any harm.
If you have a thick protective case on your iPhone, it might be a good idea to remove it while using a fast-charger, just so the heat dissipates easily and doesn’t trigger the software warnings to slow down the power flow.
Is it safe to store a charged iPhone?
Should you find you are travelling without your device or need to leave it unused for multiple weeks or months, you’ll want to ensure that it’s charged to around 50 percent before turning it off.
This will protect the battery cell from dying while left idle. The battery will still lose charge at a slow but steady rate, so after six months it will need charging back up to 50% once more.
For more ways to get the best energy performance from your iPhone see our How to improve iPhone battery life guide, or if you’re worried that the cell might be experiencing problems then read How to check iPhone battery health.
