Don’t Charge From Your Computer’s USB Ports
You can connect smartphones and tablets to your computer via a USB cable and they’ll charge. But they won’t charge as fast as they would if you plugged them into a proper, dedicated charger. In the USB 1.0 and 2.0 specifications, a standard USB port is capable of delivering up to 0.5A. USB 3.0 increases this to 0.9A on typical ports, while a dedicated charging port can offer up to 1.5A. USB 3.1, which is intertwined with (but not the same as) the new USB Type-C standard, supports up to 3A.
For example, Apple’s iPhone 6 ships with a charger that offers up to 1A. If you’re charging an iPhone 6 from a typical USB 3.0 port, you’re only getting 0.9A. if you’re charging it from an older USB 2.0 port, you’re only getting 0.5A. Modern Android phones and other devices will likely be capable of taking more power than a typical computer’s USB ports can provide, too — check your phone or tablet’s specifications to see what it’s capable of drawing. Skip your computer’s USB port and plug your phone or tablet into a dedicated charger.
A high-power USB port on a recent computer may be good enough depending on your device, but it’s better to rely on a dedicated charger if you’re in a hurry.
Use a More Powerful Charger
Rather than simply using the charger that came with your device, you can sometimes charge it faster by upgrading to a more powerful charger. For example, Apple’s iPhone 6 phones ship with a 1A (5W) charger, but they can charge faster when plugged into Apple’s 2.1A (12W) iPad charger. If you want to charge your iPhone 6 faster, plug it into an iPad charger instead of its normal charger.
Not every device will be capable of charging faster when plugged into a USB charger that can output more power. It depends on the device itself. USB charging is fairly standardized you should be able to plug any device into any USB charger and nothing will explode or catch fire. Instead, the device just draws as much power as it can from the charger. Some devices may only be capable of drawing the exact amount their included charger provides, while others can draw more power and charge faster when connected to a charger that can provide more amperage.
Feel free to use a more powerful charger - nothing should go wrong, but the phone or tablet may charge faster.
Use a Good USB Cable
Not all USB cables are equal, either. For best results, use the cable that came with the device. Cheap USB cables you buy afterwards can’t necessarily transmit the full amount of power, and may charge your phone or tablet much slower.
Put Down the Phone
This one may seem obvious, but it’s true. Consuming power while the phone is charging will slow down the process. If you’re waiting for your phone to charge and playing a demanding game on it, that game will cause your phone to consume more power and slow down the charging process.
Some people recommend putting your phone into airplane mode or even shutting it down entirely, which could help a little bit in an emergency - but is very inconvenient if you actually want to stay connected.
Use an External Battery Pack (or Car Charger)
No, an external battery pack won’t actually make your phone or tablet charge faster. But, if you need to race out the door with your phone, you can pick up an external battery pack and use it to charge your phone on the go.
Some external battery packs are even designed to function as cases you can fit around your phone to charge it without having an additional device in your pocket. If you frequently find you need to recharge your phone quickly before heading somewhere, just be sure to have an external battery pack around.
Or, if you’ll be driving somewhere in your car, get a universal car charger and charge your phone or tablet while driving.
Some modern devices support “Quick Charge,” which is actually a Qualcomm feature — but Qualcomm chipsets are part of many modern Android phones and tablets. Quick Charge allows a phone or tablet to charge much more quickly from empty, slowing down when the battery becomes more full. This could allow you to get above 50% battery capacity in half an hour. To use this, you’ll need a device with Quick Charge technology built in and a dedicated Quick Charge charger, which may not actually be included with your phone or tablet, but may be a separate accessory.
In the future, similar features will ideally spread to other manufacturers, chipsets, and devices, becoming more standardized. For now, you’ll find it on many high-end Android phones and tablets.