by Andrew Heinzman
Over the last 5 years, wireless charging speeds have leaped from around 5 watts to 10 or 15 watts in a handful of phones. That ain’t too shabby, but with new flagships like the Galaxy S20 and the Huawei Mate X sporting 45- and 55-watt wired charging speeds, wireless charging still feels slow.
Why are wireless chargers still so far behind the curve? Well, as it turns out, it’s difficult to make wireless chargers powerful without making them unsafe.
First, Let’s Review How Wireless Charging Works
Wireless chargers send power to your phone through magnetic induction and magnetic resonance. Or, in layman’s terms, wireless chargers pull electricity from your outlet, run it around a coil, and generate a magnetic field. This magnetic field interacts with a coil in your phone to generate an electrical current, which your phone uses to charge its battery.
Simple, right? Let’s go a little deeper. Faraday’s Law of Induction states that an electric field will always generate a magnetic field and vice-versa. This means that all electronics, including lightbulbs, emit a magnetic field. Sadly, a lightbulb can’t charge your phone, as your phone is built to only work with magnetic fields of a specified rate and intensity.
This specified rate and intensity are usually described as a “standard.” Modern phones are made to support a variety of different standards, like the Qi wireless charging standard. Each wireless charging standard supports different charging speeds, which is why Samsung phones with specialized coils can take advantage of 15-watt wireless charging, while other devices are capped at lower speeds.
Alright, now that we know way too much about wireless charging and magnetic fields, we can finally approach the big question: why are wireless chargers still so slow?
Wireless Chargers Could Be Faster, But They’d Fry Your Phone