In choosing the best portable USB charger, you should consider what types of devices you wish to charge and ensure that any charger can work with such devices. It can also be advantageous to look at the different amounts of charge that such chargers can hold, as well as specific information regarding the number of hours the extra charge is likely to provide for your device. If you have a background in or advanced understanding of electronics, you can also build your own portable USB charger, though this may result in damage to electronic devices.
A portable USB charger is a device that can be used with other electronic devices that are charged through the universal serial bus (USB) port on a computer. USB connections are typically used to transfer data between devices, such as digital cameras, portable media players, and printers, and a computer. The nature of a USB cable, however, is such that an electrical charge can also be sent through these cables without damaging either device. This allows many portable devices, such as mobile phones and media players, to be recharged through a USB connection to a computer that is powered by an external outlet.
If you have a device that can be charged through a USB connection, then you can typically use a portable USB charger to provide additional power to such devices. The charger is usually plugged into a wall or other power source while not in use and then carries a charge in itself. The charger can then be plugged into another device to transfer this charge into that device, acting as an external backup battery. You should be sure that any portable charger you consider is certified to work with the device you need to use it with, and you may want to look for a charger provided by the manufacturer of your device.
The information provided with a portable USB charger will also typically indicate how much charge it can carry, and how much extra usage time it will provide for a device. This will give you an idea of what charger you should choose. You can also build your own portable charger. There are a number of guides that can be found for such projects, typically using a few mobile phone batteries and some other parts. This should only be done if you have a good amount of experience in electronics, and using this type of charger could void the warranty on any electronic device you use it with, as well as cause damage to such devices.