Wireless Battery Charging- A Review

In this modern world, wireless technology is gaining a widespread interest and significance in many applications. With wireless technology, people or devices can communicate over large distances without using any cords or cables. Radio waves, cellular transmission, internet,  WiFi, GPS etc are some of the examples of wireless communication. Recently, researchers came up with the idea of wireless battery charging and were successful in showing the results for the same. The idea of wireless battery charging widened as wired battery chargers are considered annoying and bulky. Wired chargers are difficult to carry as they are at a greater risk of getting damaged and also disentangling the wires is a hard task. Also, wires get worn out and become unreliable after many charge cycles. Smart phones, wireless speakers, mics, laptops, ultra books, tablet PCs, etc all can be recharged using wireless technology. Infact, wireless power transmission can be useful for any device containing a battery inside it. This includes game and TV remotes, computer systems, electric cars, medical devices etc.

Wireless charging mainly includes the concept of inductive coupling between two circuits to transfer the energy from one circuit to another.

Working of Wireless Chargers:

It works on the principle of mutual induction wherein two coils are arranged in such a way that the change in current in one coil causes an emf (electromotive force) to be induced in the other. The wireless charging system mainly consists of a transformer having a primary and secondary coil. The primary coil is usually connected to the mains power supply. The mains is an alternating current electric power supply. When this current flows through the primary coil, it produces a magnetic field which also alternates. This change in magnetic field or magnetic flux induces an electric current in the secondary coil where the charge is required.

The device must have an appropriate hardware in it to support wireless charging (it should have a necessary coil). Also note that for a device to work in this system, it should be placed on the charging pad. Some of the devices also support wireless charging through magnetic resonance. In this case, you can place the device up to 45mm away from the charging pad. But this is less efficient than magnetic induction.

Qi inductive charging is the global standard to wirelessly charge your phone batteries. Qi uses the concept of resonant inductive coupling between the sender and receiver. The sender sends a test signal to check for resonance change and checks for compatibility to the Qi standard. On completion of the same, the charging through induction begins.

                                                                                                         

Pros and Cons of Wireless Charging:

One of the main advantages of wireless charging is the reduction of cords or cables which are perceived as annoying. Moreover, the adapter along with the cable is more prone to damage. Wireless charging eliminates our efforts to deal with messy cords and makes it easier by just placing our phones on the charging pads. Also, it is possible to charge multiple devices simultaneously. Wear and tear of cables is reduced and hence it is durable.

It is reliable and convenient to use. The Qi wireless charging standard is available in most of the public places, especially in the US. So you’d often find a charging pad in hotels and airports.

Coming to its disadvantages, wireless charging is less energy efficient compared to wired charging and therefore the charging process is slow. The loss of energy is more which is released in the form of heat. The charging station or charging pad is non-portable as these stations require the mains power supply. Also, most of the phones do not support wireless charging and the hardware required for it. Wireless chargers are also costly compared to normal chargers.

Future Scope:

Wireless technology is evolving and advancing day by day. Many devices support wireless charging like Apple iPhone 8, 8 Plus, Samsung galaxy S9, S9+ etc. Wireless charging of electric vehicles also has a future scope. With this, vehicles would be charged when they are parked or moving, thus leading to convenient use. Wireless charging also has a future in the medical field, where most of the devices consist of a battery which requires to be charged regularly.

Conclusion:

Although, it has a few disadvantages, wireless charging is convenient, easy to use and quite preferable.