Wireless power is one of the most interesting areas of development in the mobile market today, because the technology is so new, its potential is clear. Wireless charging is not only convenient, it can reduce wear and tear on ports and free up space to let hardware makers craft smaller and lighter devices, among other potential benefits.
I keep a close eye on the world of wireless power, and during the past year or so I reviewed a number of wireless chargers and "fast charge" pads, and offered insight on the latest wireless power standards. After publishing these stories, I received several versions of the same question from a handful of readers, who wanted to know whether or not their wireless chargers continue to slowly sip juice if they remain connected to a power source while not in use.
After I received another inquiry to that effect last week, it clicked that it would be a good idea to answer the recurring question in a quick blog post.
Does your wireless charger drain power when it's not in use?
Short answer: Yes, at least according to a spokesperson from Choetech, a Chinese company that makes many different wireless chargers and accessories.
Choetech says that while its chargers are in standby mode, or plugged in but not powering up a device, they draw approximately 0.05 watt-hours (Wh) per day, 1.2 Wh per 30-day month, and 14.4 Wh per year.
For some perspective, it takes somewhere around 16 Wh of energy to fully charge a dead iPhone 6s Plus, according to my calculations — which admittedly benefitted from a related analysis on the OPOWER blog. That means if you leave your Choetech charge pad plugged in for a year without ever using it to power up a device, it will drain less energy than it takes to fully charge an iPhone 6s Plus one time.
"[W]ireless charge pads continue to draw power while[they] are not in use," Choetech's spokesperson said. "But the number is so small that we can just ignore it."
Whether or not you want to "ignore" the power drain is your call. Wireless chargers do indeed draw power if they're plugged in but not being used, and they do waste much energy. If you'd rather not waste any power, no matter how small the amount, you should unplug your charger when you're done with it.