WIRELESS CHARGING TECHNOLOGY

Argument on ‘Wireless power transfer’ has been around since the early 19th century. The demonstrations by ‘Nikola Tesla’ confirmed the possibility of ‘wireless power transfer’, by creating a magnetic field between two circuits, a transmitter and a receiver. However, owing to the technical difficulties, the technology has not seen much of commercialization yet. Wireless charging, also widely known as ‘inductive charging’, works by the passage of current through two coils, which results in the development of an electromagnetic field. This generated electromagnetic field is used as a medium to transfer energy. Induction coils are present in the charging bases, which generate the needed electromagnetic fields and the second induction coil present in the device picks the current in the electromagnetic field to convert it into current and charge the batteries present in the devices. 

Recently, wireless charging technology has started to make inroads into full-scale commercialization, at least in the realms of smartphones and electric vehicles.  

The applications of wireless charging can be broadly classified into two – low power applications and high power applications.

Wireless charging in smartphones achieved commercialization in 2012 when Nokia launched Lumia 820 and 920 with the wireless charging feature. In spite of not being a consistent feature in most of the smartphones of today, wireless charging has started to gain attention among the smartphone users. However, there are some practical problems that prevent the wireless charging technology from being adopted in every smartphone today. A major hurdle is the compulsive usage of glass body or a plastic body for the wireless power transfer to happen using the current technology. This eliminates the usage of metal body smartphones, which are most desired by consumers. A complete glass body of the smartphone will increase the total price of the handset by a great margin, which will result in dispiriting the customers. Additionally, a full glass body will cause issues with durability.  These are the reasons why we don’t see wireless charging more often even in the premium segment of smartphones. Another reason for the lower adoption of wireless charging is the inability of the technology to compete with the wired chargers in terms of speed. 

OnePlus has repeatedly confirmed that they shy away from the wireless charging technology primarily due to the low charging speed. OnePlus revamped the smartphone charging segment by introducing ‘Dash Charge’ with its product OnePlus 3 in 2016. The company promised 60% of charge in battery in under 30 minutes of charging time. This garnered a lot of attention from the consumers, which eventually forced other companies to take up quick or rapid charging. OnePlus believes that customers of today prefer quick charge through wired medium over the wireless charging at low speed and thus opts out of wireless technology in spite of their latest phones sporting glass bodies. These challenges can be overcome either by a complete overhaul of the technology enabling wireless charging through metal bodies of smartphones or by developing ceramic smartphone bodies at lower costs. 

While the wireless chargers of today enable us to charge devices without connecting to wires, the technology is not completely wireless after all. There is the usage of pads and mats that act as charging bases upon which the phones are placed to power up the batteries. These pads and mats are eventually connected to power sockets by wired medium, making the wireless technology eventually dependent on the wired connectors.