Which is faster and why

Wired and wireless charging power has hit new highs in 2022. Power approaching and even exceeding 100W is increasingly common among Chinese handset vendors. The Honor Magic 4 Pro, for instance, offers both 100W wired and wireless charging capabilities. This presents us with a unique opportunity to see whether it’s faster to transmit power through cables or over the air.

Despite the identical power levels, physics would suggest that 100W wired charging will be faster than 100W wireless. The reason is that wireless charging incurs some amount of power transmission loss to heat in the coils and over the air. Furthermore, it depends on where brands and testers measure these power levels. For wireless power, in particular, numbers are often given for power at the pad rather than at the phone’s battery. So while the charging pad may see 100W, the phone may receive 80W or less. Let’s see whether this theory holds true in reality.

See also: Honor Magic 4 Pro review

For this test, we’re using the Honor Magic 4 Pro smartphone and Honor’s 100W wireless charging pad that’s powered by a 135W plug, along with Honor’s 100W SuperCharge wired plug that ships with the handset. Let’s dive right into the results.

100W wired vs 100W wireless charging test

The first thing to note is that neither Honor’s wired nor wireless charging solutions sustain 100W power for very long. We’re talking mere seconds at peak power levels, with the vast majority of charging power hovering below 50W for the wireless solution. In fact, we couldn’t quite hit exactly 100W over a wire, peaking at 92W. Short peak power is a trend we’ve seen more of in recent months as brands push power levels higher and higher in pursuit of quick marketing wins. The reality is that these charging solutions aren’t much more powerful on average, or all that much faster than what’s come before.

100W, 150W, 200W? Charging power has become a meaningless number

In terms of minutes to key charging milestones, 100W wired charging powers up the Honor Magic 4 Pro’s 4,600mAh battery to full in 29.5 minutes, while 100W wireless charging takes 33 minutes. Wired charging hits 25% and 50% battery capacities in five and 12 minutes respectively, while 100W wireless charging hits the same milestones in 6.5 and 14.5 minutes. There’s not a huge difference here, but wired charging is a minute or two faster.

As we mention, neither Honor’s wired nor wireless charging technologies sustain power levels close to 100W for any substantial length of time. We’re talking less than 30 seconds out of a charge cycle that takes around half an hour to complete. However, wired charging is able to sustain around 60W of power for a couple more minutes, giving the handset a boost in the early charging cycle. The phone also ran much hotter while charging wirelessly. Battery temperatures peaked at 42.2°C versus 36.0°C with wired charging.

So wired charging wins, as expected, even though it’s a slim margin. However, our data shows that wired still wins even though less power is transmitted over the cable. Wired charging peaked at about 92W while wireless charging reached as high as 110W, despite similar starting temperatures. Likewise, wired charging spent most of its time hovering at around 41W, while wireless charging was closer to 44W, yet was still slower to charge overall. How can this be?

More info: Everything you need to know about wireless charging

This is all expected behavior, as it comes down to where you’re testing the power draw. We test the power passing through the charging cable, which will be slightly less than the power drawn from the wall, and, in the case of wireless charging slightly higher than the power that actually reaches the phone. Charging bricks aren’t 100% efficient — there’s some loss as voltage and current are converted from the mains. In this case, Honor’s plug may be pulling over 100W from the wall but only 92W reaches the cable.

When it comes to wireless charging, Honor’s setup required you to use a 135W power brick, allowing over 100W to reach the wireless charging stand. However, the level of power reaching the phone will be quite a bit lower. There’s further loss when transmitting power wirelessly, due to coupling between the induction rings, heat, and transmission loss over the air. Anywhere around 20% wireless power loss would be quite normal.

Up next: Why your Android battery is charging slowly and how to fix it

To prove this, we’ve also crunched some approximate numbers for the power level received by the battery while charging. This data isn’t as high resolution as our charging data, so use it as a rough ballpark rather than an absolute. For wireless charging, power levels reported at the battery were approximately 24% lower on average than those recorded at the pad. That means that although the pad might pull 110W, the battery only sees 85W at its peak. Likewise, typical pad power levels around 44W would result in roughly just 33W making it to the battery.

By comparison, we calculated just a 4% average loss between the USB-C charging port and the phone’s battery. So 88W of that 92W peak wired power made it to the battery and the cell received about 39W for the bulk of its charging time, slightly higher than the power levels the battery saw while wireless charging. This helps to explain why wireless charging is slightly slower than its wired equivalent.

Although wired charging won our race, we recorded only a minute or two between key milestones and even a full charge. Fast wireless charging is virtually every bit as good as wired charging, especially at these high power levels. The real trade-off isn’t speed but heat, which, as we know, isn’t great for the longevity of internal smartphone components, hence the inclusion of cooling fans in high power wireless charging stands like Honor’s 100W model.

Would you be willing to ditch wires for super-fast wireless charging? Vote in our poll below.