Wireless charging technology has become one of the standard features in the smartphone market in recent years. This method, which is widely included in the product ecosystems of manufacturers such as Apple, Samsung and Google, allows users to transfer energy by simply leaving their devices on the charging pad without connecting or removing cables. Although it offers significant convenience in terms of daily use, it has long been known that wireless charging lags behind wired solutions in terms of energy efficiency. Research shows that this difference can have remarkable consequences not only in individual use but also in terms of energy consumption on a global scale.
According to current data, approximately 15 Wh of energy is sufficient to fully charge the same smartphone with a wired connection, while this value can increase to approximately 21 Wh with the wireless charging method. Research published by OneZero in 2020 revealed that wireless charging can consume approximately 40 percent more energy for the same process. In addition, iFixit’s tests conducted in 2024 showed that the difference between Apple’s MagSafe charging system and wired charging was approximately 36 percent. The same tests also showed that not properly aligning the phone on the charging pad significantly reduces efficiency, and in some scenarios, energy transfer can be reduced by almost half.
Electromagnetic energy transfer leads to loss of efficiency
Wireless charging systems transfer energy via electromagnetic induction. In this process, the magnetic field created by the coil in the charger is converted into electrical energy by the receiver coil in the phone. In wired charging, there is less loss since the energy is transferred directly through the conductor. In wireless systems, additional conversion processes that occur during energy transfer and the air gap between the phone and the charging pad cause a decrease in efficiency.
In addition, phone cases can also negatively affect energy transfer by increasing this air gap. According to experts, 20 to 30 percent of the total energy can be lost without being used due to heat losses that occur only during electromagnetic transmission. In addition, in all chargers, the energy loss of approximately 5 to 10 percent, which naturally occurs when the alternating current coming from the socket is converted into direct current, is also added to the system.
The difference in efficiency may seem quite limited for a single user in daily use. Although the daily difference of approximately 6 Wh does not cause a significant change in the electricity bill, the picture changes when millions of devices are taken into account. While the annual energy consumption of a smartphone with wired charging is approximately 5.5 kWh, when wireless charging is used, this figure increases to approximately 7.6 kWh.
According to Wireless Power Consortium and Deloitte Mobile Consumer Survey UK data, approximately 30 to 66 percent of smartphone users use wireless charging accessories at home. Considering that there are approximately 7.6 billion smartphones worldwide, even wireless charging of only 30 percent of them indicates an additional energy consumption of approximately 4,830 GWh per year. This amount corresponds to an amount of energy that can meet the annual electricity needs of hundreds of thousands of households. This difference is expected to grow further in the future as wireless charging solutions become more widespread.
Another consequence of wireless charging is the high temperature that occurs. The fact that the charging pads heat up significantly during use indicates that some of the energy is converted directly into heat. Modern smartphones have various temperature control systems to protect the battery. When the battery temperature reaches approximately 45 degrees, the devices automatically reduce the charging speed to prevent overheating. However, lithium-ion batteries that are frequently exposed to high temperatures may be more likely to lose capacity in the long term. For this reason, it is recommended to use charging pads on surfaces with air flow and not to leave them under heat-trapping objects such as pillows or blankets.
In addition, not all wireless chargers on the market offer the same safety standards. It is stated that low-cost and unbranded products may lack security features such as temperature sensors or foreign object detection. Metal objects entering between the charging pad and the phone can also cause unwanted heating. It is known that the magnetic fields created by some high-power wireless charging systems can interact with medical devices such as pacemakers. For this reason, people using these devices should take into account the manufacturer’s recommendations.
On the other hand, wireless charging technology is not completely static. Thanks to new standards such as MagSafe and Qi2, coil alignment becomes more precise, while losses in energy transfer are reduced compared to previous generations. However, due to its physical working principle, it does not seem possible in the short term for wireless charging to reach the efficiency level reached by wired connection.
It cannot be said that wired charging is a completely perfect solution. Charging cables can wear out over time, changing connection standards may bring about the need for new accessories, and charging ports of phones can wear out after many years. Despite this, when evaluated in terms of energy efficiency, wired charging still seems to be a more advantageous option. While wireless charging continues to be a practical alternative in daily life thanks to the ease of use it offers, it maintains some disadvantages in terms of energy consumption and long-term environmental impacts.