Inductive charging damages smartphones

Handy, wireless charging by induction causes overheating damaging to the life of the battery, even more so when the phone and the base are not perfectly aligned.

Many models of the phone can now recharge the battery by induction. This system offers the advantage of avoiding cable by depositing it on a base equipped with a copper coil producing a magnetic field that feeds the battery by induction. A practical solution, but which generates overheating very damaging for the phone, what have just shown researchers at the University of Warwick in the United Kingdom. In a study published April 17 in the journal ACS Energy Letters, they measured with a thermal camera the overheating generated in an iPhone 8 by an induction charging.
Inductive charging causes excessive heat and lasts longer, especially when the base and phone are misaligned.  © WMG, University of Warwick

Induction charging: 5 degrees more

For conventional wired charging, the temperature reaches a maximum of 27 ° C during a three-hour recharge cycle. Induction charging raises the temperature to 33 ° C in just 10 minutes. The overheating is even worse when the phone is positioned incorrectly on the base, that is to say, that the antenna of the phone and the base are not perfectly aligned. To compensate for the loss of the magnetic field, the transmitter increases its power and voltage, which generates an even higher peak of heat (35.3 ° C) and persists longer (125 minutes against 55 minutes).

Overheating is made worse by the fact that the phone and the base are in contact, one transmitting heat to the other by conduction and thermal convection, the researchers add. They advise favoring traditional corded charging if one wants to extend the duration of life of the smartphone. Also, remove the phone from its shell when charging to help dissipate heat and avoid using it at the same time.