Researchers at the University of Washington have used lasers to charge a smartphone battery wirelessly with a combination of lasers and a power cell that's mounted to the back of a smartphone, in this case a Galaxy S5 by the looks of it. According to the researchers the charging method is completely safe thanks to a inclusion of four guard sensors that will shut off the laser beams if the area in front of them is blocked or impeded, meaning it would be perfectly fine to use and then walk away from it to let the charging continue without having to stay and keep an eye on things.
The lasers will charge from a distance of up to 14 feet away from the phone and the connected battery cell, so it wouldn't have to be as close as the two units are in the video below. However, it is mentioned that the laser emitter could be adjusted to allow for an extension of the charging distance up to 40 feet which would give users a little more freedom. This would allow the phone to sit on a desk or coffee table from across the room from where the phone is as long as it's still in plain view of the device, as the lasers will need to be in line of sight of the two custom 3D printed retroreflectors (the little cubes) on either side of the battery cell.
The charging is said to be as fast as it would be if the phone was plugged in normally, though something to consider is that the phone used in the video and likely the testing, is a Galaxy S5, which charges slower than most of the phones that are available today, such as the Pixel 2 XL. It's not mentioned exactly how fast the charging is in regards to the timing, but it is mentioned the laser can deliver up to two watts of power steadily and without hesitation. Since this technology is just being researched and tested this isn't anything consumers should expect to see as a viable charging option for regular everyday use, but it does showcase that there are more than a few possible ways to charge devices wirelessly, and it wouldn't necessarily have to be for just smartphones even though that is the technology that was used for the testing.