We’ve all been there: You hail an Uber, only to notice you’re at 2 percent battery power. You applaud yourself for remembering to bring your charger but then realize you’ll be lucky to reach 3 percent before you have to unplug your phone and leave.
If your phone is a newer model and you don’t use it much, it may last the day anyway, but features such as voice navigation and video streaming will put a major dent in your battery life. If you’re nowhere near the end of your day, being left with a dead phone or having to wait while you charge up can be a drag.
Enter rapid chargers, which can charge a drained phone battery at least twice as fast as standard chargers.
Batteries work by holding a charge of electricity to power the phone. In theory, the larger the battery, the longer it should last, but battery life is strongly influenced by the power requirements of the phone. Bigger screens, for example, use more power.
A battery’s capacity, measured in milliampere-hours (mAh), indicates how much charge it can hold. Amps refers to how much charge (or current) a charger can deliver, while voltage refers to how quickly it can be delivered. The device’s overall power — how quickly and how much charge is delivered — is measured in watts.
Standard chargers that come with iPhones and older Android phones carry 1 amp of current and put out 5 watts of power. New rapid chargers with technology such as Quick Charge support 2 amps and 12 watts or more, potentially charging your phone up to four times faster.
How Quick Charge works
Android phones such as the HTC One 10 that support the newest Quick Charge 3.0 technology can be charged to 80 percent in 35 minutes. Samsung says its fast-charging wall charger with Quick Charge 2.0 tech can deliver five hours of battery life in 10 minutes — still impressive, and a godsend on a night out or long day.
Quick Charge 3.0’s optimization feature charges your phone very quickly when the battery is close to empty and then slows down when it’s about half full. This helps prevent overheating the battery and damaging its long-term lifespan.
Find out if your phone supports Quick Charge, and check your manual to see what type of charger was included with your phone.
Fast charging without damage
Not every phone can support the full power of a rapid charger. For example, the iPhone 6 supports 1.6 amps and comes with a 1-amp charger. A 2.2-amp charger like the charger for your iPad will not charge your iPhone twice as fast; you’ll only charge as quickly as your phone can handle. Older iPhones that support only 1 amp can’t be charged faster at all.
To find out your phone’s amperage, search online for your model. If your phone’s battery can be removed, pry open the case and check the fine print.
To avoid battery damage from rapid charging, use only authentic chargers, says Joe Silverman, CEO and owner of New York Computer Help. Fast charging from certified chargers (from your manufacturer or a third party) will not damage your phone’s long-term battery life. What might hurt your battery are knock-offs or generic chargers made from cheaper materials that don’t ground electricity properly, which causes a leaking charge that can damage the battery — a problem for about 10 to 15 percent of customers who come in with battery issues, Silverman says.
Even if you use a higher-amperage charger on a lower-amperage phone, remember that certified and in-box chargers are designed for particular devices. They will not let through more power than the phone can support.
How to charge your phone faster
Whether or not your phone supports fast charging, you can boost how fast your phone powers up.
Use the wall plug
Got a USB cable? Forget charging from a laptop. Stick your cable into the AC plug that came with your phone and plug that into the wall. Standard AC plugs deliver 1 amp of current, twice what’s possible via the USB 2.0 socket found on many computers. Third-party AC plugs may support higher amperage up to 2.4, although you’ll be limited by the amperages of your phone and your USB cable.
Our picks: The Anker PowerPort+ 3 triple-USB wall charger ($29.99) supports Quick Charge 3.0 and can charge other devices with current up to 2.4 amps. The Aukey wall charger with USB cable ($11.99) works with Quick Charge 3.0 and 2.0 devices, as well as other devices, and charges at currents of 3 amps, 2 amps and 1 amp. And the AmazonBasics wall charger ($5.99) produces 2.1 amps and serves as our pick for the most basic USB wall plug.
Use a higher amp car charger
Just like you'll want a higher amperage wall chargers, you'll want a car charger with Quick Charge and/or the ability to deliver more than 1 amp. You'll find car chargers that support Quick Charge 2.0 and 3.0 as well as regular chargers that deliver up to 2.4 amps
Our picks: The Anker PowerDrive+ 2 with Quick Charge 3.0 dual USB Car Charger ($25) plugs into your car's cigarette lighter and charges two devices—tablets and smartphones—at the same time. If you just need to charge one device quickly, try the less expensive 9to5Cables Dual USB Car Charger ($7.99).
Upgrade to USB 3.0
The USB 3.0 standard supports up to 1.5 amps of current when charging without data transmission. Using a USB 3.0 cable in a USB 3.0 port charges your phone faster, assuming your phone supports 1.5 amps or more.
If you charge your phone from a USB 3.0 port on your computer, turn on Airplane Mode to ensure your phone won’t try to sync or interact with the computer. Otherwise, the allowable current is capped at 0.9 amps. Check online to find out if your computer model has USB 3.0 ports.
Our picks: Try the AmazonBasics USB 3.0 cable ($5.49) for USB 3.0 to Micro USB. And for USB-C Phones, the Anker Powerline+ USB-C to USB 3.0 cable ($13.99) is an extra-durable cable for rapid charging and data syncing.
Use your iPad charger for your iPhone 6 or newer iPhone
The standard iPhone 6 1-amp charger can take the phone from zero to full in around three hours, and the 2.1-amp iPad charger can halve that, says Silverman. Or pick up an Apple-certified third-party wall charger.
Our pick: The Kensington AbsolutePower wall charger ($12.99) has a Lightning cable hardwired to power up your phone at the maximum 2.1-amp capacity of new iPhones.
Turn off your phone while it’s charging
Without Pokemon Go or email sucking up processing power, more juice goes where it’s needed sooner.
Lock the screen
If you can’t live with a turned-off phone, let your screen go black to get more power to the battery.
Leave low power mode on
When you hit a certain battery level, this handy setting for iOS and Android devices automatically dials back screen resolution, animations, background app refreshing and other battery drainers. It’s an impressive extension of battery life, and Silverman says this feature doesn’t affect how fast your phone charges.
[Image credit: smartphone and charger via Shutterstock, Anker, Kensington]