1 Watt might not be much, but did you know that a LED with merely that much power is able to illuminate an entire room in darkness bright enough for objects to be clearly visible? This means that the power of an average power bank could illuminate an entire room for around forty hours! 1 Watt is not that bright of course, but bright enough for the human eye to clearly recognize objects and the surrounding. Thanks to LED efficiency, many integrated LEDs in mobile phones and power banks (often around 2W) are able to sufficiently illuminate an entire room in an emergency situation. Very practical.