Wireless charging is a feature that enables devices to charge wirelessly without having to physically connect them to a charging cable. Surprisingly, this form of charging technology has been around since the late 19th century. Wireless charging was a concept that was created by Nikola Tesla when he demonstrated magnetic resonant coupling, which is the ability to transmit electrical current through the air by creating a magnetic field between a circuit that acts as a receiver, and another circuit that acts as a transmitter. Because this revolutionizing technology was introduced at such an early time in history, there were not any practical applications that could use this form of technology, until today. Nikola Tesla's discovery in the 19th century has become the foundation of wireless charging and reverse wireless charging that is used in modern technologies today. A few examples in our modern-day society would be devices that range from smartphones to appliances to even cars that are capable of wirelessly charging other devices as well as itself. As our technology enhances, we find more of a need to cut the cords and make everything wireless.
Reverse wireless charging is the same concept as wireless charging, however, the difference is instead of the transmitter being the transmitter and the receiver being the receiver, the receiver can turn into either the transmitter or the receiver, giving it the ability to charge itself wirelessly, as well as, charge other devices using its own power bank as a fuel source. Confused? Think of Reverse wireless charging as a walkie talkie. For example, when person A talks to person B then person A is the transmitter while person B is the receiver, and vice versa. The idea behind that analogy is both person A and person B can be both the receiver and transmitter based on the situation. Reverse wireless charging is the same principle, for example when you need to charge device A it turns into a receiver, but, if you need to charge another device say device B, device A can charge device B by turning into a transmitter and using the charge you have on device A. Reverse wireless charging is a feature that is relatively in its infancy, however, it has definitely been a feature that is rapidly gaining popularity by users, and being added to several devices.
As we know wireless charging is a convenient way to charge your devices without having to plug charging cables into your device, but how fast is the charging? Honestly, the speed really depends on your device and your charging device (receiver and transmitter). To explain, depending on the type of wireless charging input your device has and how much the charging pad or device output has would determine your actual speed. For example, the fastest wireless charging pad we have seen is able to charge up an LG v30 from 0% to 57% in just under an hour. But the reason we received this speed is because we used an Android-powered phone which was able to take an input of close to 10W while an iPhone would only be able to take an input of 7.5W. As you can see there are several factors that determine wireless charging and it is something that is still being innovated.
When it comes to reverse wireless charging the main difference is, everything rests on the device battery, the transmitter, and receiver in the charging device. To explain, if you are using a phone that supports reverse wireless charging then you would have to make sure your battery is above a certain threshold, as well as, figure out how much current it can transmit without the unit becoming dangerously hot or setting on fire. To put it out there, reverse wireless charging is very slow compared to regular wireless charging. Reverse wireless charging is primarily intended for emergency charging situation. That being said, at this current moment reverse wireless charging does not have a set standard on how long it takes to charge a device. However, based on a few tests we ran using the Samsung Galaxy S10+ we were able to charge a completely dead phone to 10% in 30 minutes. As we mentioned before reverse wireless charging is very slow, however, don’t forget reverse wireless charging is intended for emergencies like when a friend’s phone is about to die and you need to give them a little of your charge, or if your headphones are about to die and you have enough battery to spare from your phone to recharge them.
As we mentioned above, reverse wireless charging is something that is gaining popularity at a rapid speed and because of that several devices and manufacturers have been adding and adopting it as a premium feature. The two brands that are currently leading and well known regarding reverse wireless charging are Huawei and Samsung. The first company to bring this feature to the phone is Huawei in the Mate 20 Pro and Mate 30 Pro which then followed by Samsung in the Samsung S10 series, S20 series, 5G series, Note 10, and a few more. In the near future, there will be more manufactures and devices that support reverse wireless charging, and it definitely will be one of their biggest points when marketing their devices.
This is a feature that would be extremely helpful and useful after it matures a bit, and for that reason, we would say no it is not something that people should be prioritizing right this moment. To explain, just like every technology that gets created and released to the public there will be hype and issues. From our experiences we recommend, it is a better idea to wait so the issues that arise are somewhat ironed out and the feature gets a bit more reliable. If you look at the cost-benefit analysis of this feature it is definitely not worth it. To explain, if you could charge a friend's phone to 10% in 30 minutes using your own phone but the cost of doing that would increase your phone's price by 150 dollars, could you justify 150 dollars for 10% that you might or might not ever use? Is the concept great and does it have practicality? Most definitely. However, we believe it is better to wait for a second or third generation of reverse wireless charging. Wouldn’t you rather pay an extra 200 dollars for a device that could bring your charge from 0% to 80% vs 0% to 10% in 30 minutes?