A cordless charger provides charge to the battery in an electronic device without a cord extending from the device to the power source. In some cases, this means that the device, or its battery, is plugged directly into the wall. Other cordless chargers use induction to transfer electricity to a device that is set on top of it. Solar and battery powered chargers are other types of cordless chargers.
One type of cordless charger is a wireless charging pad. This charger pulls energy directly from a wall outlet and transfers it to various electronic devices, such as cameras, cell phones and electronic readers that are placed on top of it. One of the advantages of charging with a pad is that multiple devices can be charged at the same time. The charging pad is limited to about six small electronics at a time, which is about the number that will fit of the surface of it.
Devices charged with a charging pad must be connected to a receiver in order to obtain electricity without plugging into the charging pad. Receivers can be attached to the outside of the device or to the battery inside. The devices are charged through induction, which is the transfer of electromagnetic energy from one coil to another. In the case of a charging mat, one of these coils is in the mat and the second is in the receiver attached to the electronic device.
Another type of cordless charger is a portable solar cell. Small electronic devices plug into the charger, which is able to draw energy from exposure to direct sunlight. Solar chargers may be specifically designed to work with a certain device or may come with a series of attachments in order to connect to various electronics. These chargers are useful for travelling to places where electricity may be limited or unreliable.
A cordless charger may also plug into a wall socket and then directly into an electronic device. These chargers only work with small devices because the device will need to sit on the charger, above the wall socket, while it is charging. Sometimes these types of chargers can be designed to charge a battery that is taken out of the electronic device.
Emergency chargers are also available that can charge a device without access to an electrical outlet. Powered by batteries, an emergency cordless charger can plug in to a number of different types of electronics. The electronic devices pull power from a battery powered charger in the same way that they would from a wall socket. Emergency chargers can come with disposable or rechargeable batteries.