Wireless Charging

What it's all about and how it works

Wireless-charging technology is not new. The Palm Pre smartphone had it back in 2009. The technology uses electromagnetic waves to transmit energy by inducing a current within a coil inside the device, which charges the battery.

The wireless chargers in the market generally require close proximity to the device, though companies are developing wireless charging solutions that work from a distance.

Having wireless charging in a mobile device helps to reduce wear and tear of the device's charging port.

It could also help prevent inadvertent damage to the port. Most phones use the micro-USB port that needs to be plugged in the right orientation and may be damaged by improper use.

However, newer smartphones are switching to the USB Type-C variant that, like Apple's Lightning connector, has a reversible plug. This makes it almost impossible for users to plug the connector wrongly and damage the port.

Wireless-charging transmitters can also be integrated into desks, lamps and even desktop monitors to create a seamless, cable-free look in homes, offices and public venues.

Swedish furniture retailer Ikea has been selling a range of wireless-charging home furniture in Singapore since May.

An Ikea spokesperson described local sales as encouraging, but declined to reveal exact sales figures.

Wireless charging has its drawbacks. It typically takes longer as it is not as efficient as wired charging.

A study by the Colorado State University found the Qi wireless technology to be between 60 and 70 per cent efficient in power transfer.

This inefficiency shows up in the form of heat. And as the wireless charging surface gets warm, it could also shorten the lifespan of the phone's battery over time.

Vincent Chang

A version of this article appeared in the print edition of The Straits Times on August 03, 2016, with the headline 'What it's all about and how it works'. Print Edition | Subscribe