Modern smartphones cannot do without mobile connectivity. You can use mobile data or rely on Wi-Fi. Although Wi-Fi is generally assumed to be more energy efficient than connecting to 5G networks, but by how much? A recent test showed that the difference in battery consumption of the iPhone 17 Pro Max between the two network technologies is very significant. For older iPhones, this difference in endurance can be even more significant.
A test of the latest iPhone today showed that the connection to 5G is a significant power eater compared to Wi-Fi
Table of Contents
Two freshly reset iPhone 17 Pro Max took part in the test with a newly added account and the same display brightness throughout the testing period. One was connected to Wi-Fi (specifically Wi-Fi 6E, with the router located within five meters of the phone, i.e. at an ideal distance), the other exclusively to the 5G network. Both phones had their sound turned off, which did not affect the test results in any way. How did it all turn out?
Wi-Fi with a decent lead
The phone connected to a 5G network lasted 10 hours and 22 minutes in this test with the display on, and another 16 hours in standby mode – that is, locked with only background communication. When the phone shut down due to low battery, the other iPhone was still connected to Wi-Fi 25% battery capacitywhich corresponds to approximately three hours of continued use. This test quite convincingly explains why iPhones discharge faster when traveling than at home – it’s not just a coincidence.
The conclusions can be generalized to other phones as well. A permanent connection to the mobile network is more energy intensive because the phone must receive and transmit signals to the BTS, which is significantly further from the device than the Wi-Fi router. Local Wi-Fi won the test by a significant margin, despite the fact that the test did not include other parameters common to network communication.
Moving the phone involves switching between different BTSs, which is a power-intensive operation. In addition, the signal strength often fluctuates, phones switch to lower network technologies when necessary, and whether you are moving in the city or in the countryside also plays a role. Also on network modes, whether it is SA or NSA network, or on the frequencies that the phone uses. In tests of specific applications, the complexity of the displayed content (video versus static image) may also differ, which must be taken into account in this type of testing. With Wi-Fi, it can also depend on the specific version supported by both the router itself and the phone.
However, this test made it clear that 5G can be a very significant power drain on the iPhone – typically in situations involving heavy downloading or uploading of data. For example, during a two-hour FaceTime call, the phone using 5G drained 17% more than the one connected to Wi-Fi. During two hours of scrolling on Instagram, the difference in battery drain was three percent, and in other partial tests it was even smaller.
For older iPhones, the differences are even greater
Testing was conducted on an iPhone 17 Pro Max with the latest 5G modem from Qualcomm, which is considered very energy efficient. If you have an older iPhone with a less efficient modem, they might be the differences even more pronounced. The iPhone 12 Pro Max lasted 19 hours and 46 minutes on Wi-Fi while playing streaming video, and just nine and a half hours when connected to a 5G network. Turning on Wi-Fi increased battery life by 108%, while the iPhone 17 Pro Max saw an 87% increase in the same test – thanks to a more efficient modem.
Unfortunately, we do not know how the test with Apple C1 modems would turn out. But with older modems, it is clear that the difference in endurance when using Wi-Fi and 5G separately will grow even more
Of course, other test scenarios would also be interesting – for example, the difference in discharge speed between 4G and 5G networks or an identical test for iPhones with their own Apple C1 and Apple C1X chips, whose main advantage, according to Apple, is energy efficiency. The next time you go on a trip or a business trip and you are surprised that your phone is draining faster, keep in mind that this may be due, among other things, to the fact that the smartphone is not connected to Wi-Fi, but to a 5G network.
date:2026-02-11 07:57:00