To get a sense of how much extra power is lost when using wireless charging versus wired charging in the real world, I tested a Pixel 4 using multiple wireless chargers, as well as the standard charging cable that comes with the phone. I used a high-precision power meter that sits between the charging block and the power outlet to measure power consumption. In my tests, I found that wireless charging used, on average, around 47% more power than a cable. Charging the phone from completely dead to 100% using a cable took an average of 14.26 watt-hours (Wh). Using a wireless charger took, on average, 21.01 Wh. That comes out to slightly more than 47% more energy for the convenience of not plugging in a cable. In other words, the phone had to work harder, generate more heat, and suck up more energy when wirelessly charging to fill the same size battery. [...] The first test with the Yootech pad -- before I figured out how to align the coils properly -- took a whopping 25.62 Wh to charge, or 80% more energy than an average cable charge. Hearing about the hypothetical inefficiencies online was one thing, but here I could see how I'd nearly doubled the amount of power it took to charge my phone by setting it down slightly wrong instead of just plugging in a cable.
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