August 11, 2012, 7:25 AM — Most smartphones, digital cameras, MP3 players, and other small gadgets have one thing in common: They can charge via a standard USB port.
As a result, many users top off their devices' batteries by plugging them into laptops, desktops, or mobile USB chargers. That's a convenient way to go--but often a slow way as well.
See, a typical USB 2.0 port (like the kind found on most PCs) delivers up to 500 millamps (mA) of juice. But a typical AC wall charger for, say, a smartphone will supply more like 900mA or 1,000mA--even though you're plugging that same USB cable into the charger.
Translation: If you want faster charging for your gear, use a wall charger. Likewise, a car charger (the kind that plugs into a cigarette lighter) will outperform a PC's USB port, as they can deliver anywhere from 1,000-2,100mA.
If your device didn't come with a wall charger (I'm looking at you, iPod Touch), you can find a gazillion options on Ebay. Just one random example: a 1,000mA USB AC charger for $1.99 shipped. Though the description says "for iPhone," it'll work with just about any mobile device.
One exception: large tablets like the iPad. Apple's wall charger for that device delivers 2,100mA, and although you can use a "smaller" charger, it'll take an awful lot longer to fully replenish the iPad. See, tablets have bigger batteries, and therefore need bigger AC adapters.
Want to learn more about the finer points of USB charging? Check out ExtremeTech's "How USB charging works, or how to avoid blowing up your smarthphone."
In the meantime, if you want to charge your gear faster, bypass those USB 2.0 ports in favor of a wall charger. (Bonus tip: If your PC has a USB 3.0, it can deliver 900mA, or about the same as a wall charger. All the more reason to insist on that feature for your next laptop!)
Contributing Editor Rick Broida writes about business and consumer technology. Ask for help with your PC hassles at email@example.com, or try the treasure trove of helpful folks in the PC World Community Forums. Sign up to have the Hassle-Free PC newsletter e-mailed to you each week.