Many of today's popular smartphones can be wirelessly charged by simply placing the device on the surface of a small charging station, but users often have the feeling this is slower than charging by cable. Now it's official. A test by respected German computer magazine c't has found it takes around 50 per cent longer.
Under certain circumstances it can take more that an hour longer to fully charge the battery. This probably won't be a problem if the device is being charged overnight, but if you're in a hurry the experts advise plugging in the phone instead. Another disadvantage when charging wirelessly is that the phone is only of limited use during the charging, as it's supposed to lie undisturbed on the charging station. This is particularly troublesome during the day when you're likely to be picking the phone up a lot.
Given these drawbacks, wireless charging is more for aesthetes who want to keep their home or workspace free of cables, the experts say. The charging stations on the market often have good designs resembling, for example, a small pillow, a chic wooden disc or a stone. There are even chargers that can be built almost invisibly into furniture.
In wireless charging the energy from the charger is conveyed to the phone via electromagnetic induction. To achieve this, both devices contain a thin coil. There are various technical standards on the market, but the one most commonly seen for mobile devices is the Qi standard.