Apple is one of the first few companies that experimented with wireless chargers with its MagSafe device in 2006.
Apple is one of the first few companies that experimented with wireless chargers with its MagSafe device in 2006.
Wireless chargers are increasingly powering smartphones, TWS earbuds, smartwatches, and several other consumer electronic devices. Wire-free charging technology transmits energy from a power source to the device on the principle of magnetic resonance, or simply put, inductive power transfer.
(Sign up to our Technology newsletter, Today’s Cache, for insights on emerging themes at the intersection of technology, business and policy. Click here to subscribe for free.)
Smartphones have become the center of today’s digital lifestyle, and consumers want their devices to be charged on the go to access information, make purchases, maintain contact with friends and family and tap emergency services when needed, according to Sanjay Gupta, VP and India Managing Director at NXP Semiconductors.
Companies and chargers
Several companies are developing wireless charging technologies. Apple is one of the first few companies that experimented with wireless chargers with its MagSafe device in 2006. It discontinued the chargers in 2019, and then re-introduced them in October 2021 for its new line of iPhone models. The Cupertino-based company never stated the reason for discontinuing the technology three years ago. But it did receive complaints from several users on insulation and overheating issues.
The Silicon Valley company’s competitor in South Korea has also developed wireless chargers. Samsung’s wireless charging pads can power up two devices in one go. The 15W charger can charge a phone, earbuds or smartwatch. And then, Shenzhen, China-based mobile manufacturer OnePlus has built a stand to power its smartphones. This device can charge a phone from 1% to 50% in 29 minutes. It can also charge other brand smartphones that are Qi/EPP compatible. Qi/EPP is the worldwide standard for wireless charging technology .
Another Chinese handset maker Xiaomi makes 30W and 50W wireless charging stands to charge phones. And companies flagship phone is said to offer one of the fastest wireless charging speed in the industry at 50W. Last year, Mi introduced a tech that enables users to remotely charge multiple smartphones at the same time without any cables or wireless charging stands.
The charging pile can accurately detect a smartphone’s location and transmit millimeter-wide waves to the phone. The beacon antenna in the smartphone broadcasts position information and the receiving antenna converts the millimeter wave signal into electric energy that charges the phone.
In another category of devices, flash memory driver maker SanDisk sells a 10W charger that supports fast wireless charging for Qi-compatible smartphones. It can also automatically backup photos and videos in full resolution right onto the charger, every time the phone is charged. This feature is said to free up data storage on phones as the data is backed up on the chargers.
Challenges facing wireless charging technology
Charging time and output are the biggest challenges for wireless charging technology remains around the time and maximum output as they are not as fast as the wired chargers, according to Xiaomi India’s chief marketing officer Anuj Sharma.
The average power output for wireless charging is 10-20W. And most android devices powered by regular chargers provide about 33W output for smartphones in the mid-range and above. Additionally, wireless chargers are more expensive compared to wire based chargers as the adoption for the technology is yet to pick up.
Some experts have expressed concern over charging tech’s design, noting that inefficient design could cause extreme temperature fluctuations in the wireless charging system. This in turn could affect its performance, causing inoperable damage. Others have also pointed out the tech’s negative impact on smartphone batteries. A research report by the University of Warwick revealed the use of inductive charging could drain mobile phones powered by lithium-ion batteries.
Charger makers refute these issues, saying wireless charging is completely safe and that it does not affect the battery life of products.
In a separate use case, researchers have identified some wireless chargers to be affecting the functioning of pacemakers. The American Heart Association (AHA) found that devices with Apple’s MagSafe technology can cause clinically significant interference in cardiac devices like pacemakers when they are placed close to these devices or on the skin.
MagSafe can generate magnetic field strength of more than 50 gauss. “Apple’s iPhone 12 Pro Max MagSafe technology can cause magnetic interference on cardiac implantable electronic devices (CIEDs) and has the potential to inhibit life-saving therapy,” AHA said.
People often put their smartphones in a breast pocket which can be in close proximity to CIEDs. This can lead to asynchronous pacing or disabling of life saving therapies, according to the AHA.