Why Is Wireless Charging Slower Than Wired Charging?

If you’ve ever tried out wireless charging, you’ve probably noticed that it’s not as fast as charging your phone with a traditional cable. At first glance, it’s easy to assume that the convenience of simply placing your device on a charging pad should come with the same speed as plugging in a charger. But if you put your phone on a wireless charging pad and watch the percentage go up, it is frustratingly slow compared to a wired charger giving this quick burst of power. Why is that? In the coming discussion, we will explore in depth why wireless charging is always somewhat slower than traditional wired charging, and then take a closer look at what factors really make these two methods of powering up so different from one another.

Basic Understanding: What is Wireless Charging?

But before we dive into why wireless charging is slower, let’s take a look first at how this works. Wireless charging, which is also sometimes referred to as inductive charging, utilizes electromagnetic fields between two objects to transfer energy—in this case, a transmitter being a charging pad and the receiver, your phone or device.

When your device is placed on the wireless charger, an induction coil in the pad creates an electromagnetic field. This magnetic field then induces an electric current into the receiver coil in your phone, converting it into a usable electric charge that fills your device’s battery.

This may sound quite simple, but it’s not just as easy as plugging a cable into your device. The efficiency in this transfer has several factors that will bring us down to why wireless charging often seems slower than the wired one.

1. Energy Loss in Transmission

The greatest reason wireless charging is slower compared to wired charging is the energy losses during the transfer. When you plug a wired charger into your phone, power goes directly from the outlet to your device through a physical cable with little to no energy loss. In essence, the speed at which your device will charge is dictated by just how much power the charger can deliver directly to the battery.

However, in wireless charging, energy has to cross through air, meaning more energy is lost in the process of transmission. Inductive charging isn’t a perfectly efficient system, and so some of the power is lost as heat. In other words, only some of the energy that’s generated by the charging pad actually makes it to your phone’s battery. This makes it less efficient and translates to longer charging times as opposed to wired charging, which delivers energy directly through the cable.

2. Lower Power Delivery

Another factor that controls the speed of wireless charging is the maximum amount of power that can effectively be delivered by this method. Wired chargers have the advantage of being able to deliver much higher power directly into your device for faster charging speeds. That means, for example, while a wired charger might be able to pass 18W—or even 45W or more—to your phone, most wireless charging pads top out at around 10W, with high-end options going up to 15W for certain devices.

The lower power output means that, even if you place your phone on a wireless charger, it simply won’t receive as much power at once compared to that from a traditional plug-in charger. This is especially noticeable with newer smartphones and other devices that have bigger batteries, which naturally demand more power in order to charge quickly.

3. Space Between Charger and Device

In the case of wireless charging, efficiency is highly related to the distance between the phone and the pad: there is a huge loss in case of a gap between them. This is because electromagnetic fields formed around the charger are strong when the phone is close to the pad, and even slight misalignments result in lost efficiency.

This means that, in wired charging, the flow of energy between the charger and your device is very effective due to a physical connection that offers little or no loss of energy due to slight misalignments, provided the cable is properly plugged in.

While new models of wireless charging pads have features like alignment indicators, any obstruction between the charging pad and the device contributes to negativity in the charging speed.

4. Heat Generation

As said earlier, the loss in energy while wireless charging is in the form of heat. High heat while wireless charging does not only reduce the charging speed but can even potentially affect the battery life of your device over some time. Your overheating phone automatically starts using thermal management systems so as not to let any kind of damage to the battery by throttling down the charging speed for keeping things cooler.

Wired chargers can also generate heat, especially during fast charging, but because they are wired directly into the device and generally more efficient, they often don’t see these types of heat-related slowdowns that wireless chargers do. This added layer of protection in wireless charging translates to slower speeds but ultimately can help prevent overheating damage to your device.

5. Technology Limitations and Standards

As of now, the wireless charging technology still has some considerable ways to go in keeping up with the wired charger’s pace for a quick device charge. The normal Qi wireless charging technology, while widespread and quite good for general purposes, is rather limited with respect to the speed at which energy can be transferred.

In contrast, wired fast charging technologies—such as Qualcomm’s Quick Charge or USB-Power Delivery (PD)—are designed to pump out much higher power, resulting in dramatically faster charging speeds. As wireless charging technology improves over time, we’re likely to see the development of higher power delivery through wireless pads, which would narrow the gap in charging speeds between the two methods.

6. Environmental Factors

Other environmental factors that may further distinguish wireless charging from wired charging are at least a few more. The best operation of a wireless charging would work when it faces minimal interference from metal objects, moisture, and even extreme temperatures. Devices enclosed by metal surfaces or heavy interference may suffer from reduced power transfer, hence slow charging. Positioning your phone properly on the charging pad also plays a major role in how efficiently energy is transferred. Given these challenges, future wireless charging pads will adapt to different environments and deliver faster charging speeds as technology advances.

So, What Can Be Done?

Even while the convenience of this comes at great value, it presently cannot compete on a speed front with wired charging. Wireless charging does have a future ahead. Technology such as fast wireless charging and enhanced magnetic resonance—the class of wireless charging working on a much farther distance—is shrinking the speed differential between wired and wireless charging day after day.

Conclusion: The Best of Both Worlds

Wired charging is still the more efficient method for those in a rush. For convenience, though, it’s hard to match the art of being able to set your phone down in a rush and not have to mess with cords and cables. In the future, wireless charging will continue to get more efficient, and for many, the tradeoff of slower times for that convenience will be well worth it.

Ultimately, both wired and wireless charging have their advantages and downsides. Depending on your needs and the tech available to you, you’ll likely use both methods at different times. The key takeaway is that as technology evolves, so will the speed of wireless charging, making it an even more compelling option for tech users worldwide.