Wireless charging (also called wireless charging, wireless energy transfer or Qi charging) is something incredibly practical. Wireless charging is especially popular for smartphones. But smartwatches (e.g. the Samsung Watch Active), headphones (e.g. AirPods), tablets, MP3 players and thousands of other products can also be charged wirelessly. In terms of cell phones, these include various devices from Samsung, Apple (iPhone 8 and up), Huawei, Google, LG, BlackBerry, Sony, Nokia and Motorola, which can be charged wirelessly. Cell phones without built-in wireless charging can in most cases be retrofitted with a QI receiver that is built into a suitable cell phone case (e.g. Andi be free), or attached as a sticker on the back of the cell phone or under the battery cover. How does wireless charging work? Wireless charging is done by induction. Both the wireless charging station ("transmitter") and the device to be charged ("receiver") contain coils through which current can flow. As soon as the transmitter and receiver are in contact with each other, the charging process is started by induction. The coil of the charger transforms the electric current into a magnetic field, which is converted back into electric current in the coil of the cell phone. Thus, the cell phone is supplied with power just by touching the charging station. A simple example is electric toothbrushes, which are also charged wirelessly on their respective docking station. Or just as in the case of a cell phone, the phone is placed on top of the wireless charging station (often in the form of a pad or pillow). There are different methods for wireless charging, e.g. induction, radio or resonance charging. For cell phones and other medium-sized devices, the induction method clearly dominates. There are also various standards for wireless charging. The most common is the Qi standard, named after the Chinese word "Qi", which stands for life energy. With the common Qi standard, an iPhone can also be charged with a Samsung charging station, for example. You only have to consider the power of your charging station, because the charging speed depends on it. Chargers with 5W, 7.5W and 15W are common. Samsung uses the latter for the Galaxy S8, for example, and can charge the phone's battery comparatively quickly. Apple initially uses the 7.5W standard for its first wirelessly rechargeable smartphones. Of course, the iPhone could still be charged on a 15W station, but it will not have a full battery quite as quickly. The radiation that is generated during wireless charging is vanishingly small. However, to avoid unnecessary radiation, you should always remove fully charged phones from the charging station right away.