Recently my iPhone dropped below 10% and the low-power mode indicator popped on. As soon as I plugged the phone in I switched off low power mode and then wondered why I was in such a hurry to do so. So, I look into iOS low power mode to see exactly what it is doing. What I found surprised me, and made me realize I should probably leave it on more.
What iOS Low Power Mode Does
The iOS Low Power Mode setting is not one that is given too much thought by most people, but it is a pretty heavy-duty feature. First, it disables some settings that consume a lot of power. These include mail fetching and background app refresh. Low Power Mode also adjust screen brightness to be a bit lower. It has some impact on other visual settings, as well, because it throttles the phone’s CPU and GPU. Tests have shown that low power mode can slow the phone by approximately 40%. This might be a problem for you if you run graphics-heavy applications like games.
The most important adjustment to me is found on Apple’s support site. According to Apple, iOS Low Power Mode “reduces or affects” the Hey Siri functionality. Since there is no global setting to disable Hey Siri in iOS 11, I want to minimize it to the maximum possible extent.
How I Use Low Power Mode
Unfortunately, this setting is only enabled when the user enables it or when power drops below 10%. The phone reverts to normal power mode when it reaches an 80% charge. You will have to go back in and reenable Low Power Mode. It is easy to forget to do, but I’ve made a habit of checking this setting every morning when I first unlock my phone upon leaving the house. Because it minimizes Hey Siri and background app refresh (and extends my battery life!) I want to leave it on all the time. You can make this process a bit easier by adding iOS Low Power Mode to your phone’s Control Center (Settings >> Control Center >> Customize Controls).
To be clear, this isn’t an extreme privacy intervention. It’s a very small, incremental upgrade. Some of you may not like the reduction in speed (especially on older phones) but I run so few apps I have yet to notice. I have also been exceptionally pleased with the extended battery life. To be able to get some additional privacy benefit from that is a bonus.