The best USB power supply I have seen is the Anker 5 port, 8 amp smart charger. It uses a so-called PowerIQ charging system to provide the best power possible for each device. It is a small brick shaped device that connects to the wall via a figure-eight cable.
A USB based charger can charge most portable devices, from Android phones and tablets, iPhones, iPads, Bluetooth headsets, Cameras, to a wealth of other devices.
Most of these devices come with a “wall wart” plug pack and a USB to micro or mini USB plug, or the Apple Lightning connector. Carrying the original charger for every device we own, and finding a power outlet for each is impossible.
The Anker charger is a small brick, smaller than a cigarette packet, (58 x 91 x 25mm) with 5 USB ports on one end and the small two-pin figure eight socket on the back. The advantage of this (and the wide power supply range) is that the charger can be used in any country with the addition of the correct cable. It can be found on Amazon here and eBay here.
Every USB device makes it’s power requirements known by talking to the charging port via serial communications through the two inside pins, or, for dumb charging devices, by being wired with certain resistors in the power lines. This allows a smart charger to supply just the right amount of power to each device. The Anker charger is very well regulated, and assuming the cables are of suitable quality, maximum charging speeds will result. Overcharging is impossible as long as decent cables are used. I label the cables that come with my devices and try to keep the correct cable with each device. I have only once seen a different cable to cause a problem. It was supposed to have a “Fast Charge” switch on the plug. switching to “Fast Charge” caused charging to stop completely! More about cables another time.
I found the results to be impressive, though I could never get my HP Chromebook 11 to charge at anything like the 3 amps that it’s dedicated charger is supposed to deliver. But I torture tested the Anker charger on a one week stay in Melbourne recently. I was sharing accommodation with three other device users. Each night four smartphones, three tablets, a USB charged HP Chromebook 11, a power bank, Bluetooth headsets, two keyboards and a USB powered Seagate WiFi hotspot and media server all had to be kept topped up by the Anker IQ 40W 5-port smart USB charger. It worked flawlessly for the week, charging everything, in some cases with split two headed charging cables connected.
The Anker IQ 40W 5-port charger comes with an 18 month warranty, and this is backed by an impressively fast and helpful customer support operation. My first charger had one port die within a week. Anker asked for the serial number of the device, and had a replacement in the mail within 24 hours. Since they are in the US and I am in Australia the replacement arrived with great speed. A tribute to a real belief in quality and customer support.
Anker now has a 60W version, but I seriously doubt it will result in faster charging except with the most extreme combination of devices. But if you believe more is better, here is a link to the 60W charger on Amazon.