Observation-Battery Discharge and Safari in Background

NSquirrel · Nov 17, 2019

When you put your phone in sleep mode and you leave your iphone with Safari still launched and on a say a news page, which updates frequently, even though the phone is asleep, the battery discharges as the news page is updated. There is, apparently, no way to turn off background refresh for Safari specifically, unless perhaps you turn off background refresh totally. (We like to leave one specific app in background refresh mode in case of contact from our daughter.)

Personally I always shutdown each app as I finish with it to stop background refresh, unlike our other iphone which often has recent apps still launched. Last night the other battery discharged to almost empty and the battery info suggested that only Safari had been launched. This may also happen with a similar page on a Safari tab.

(The above is for two iPhone 8's; so may or may not be true for other models.)

Edit: 2 minor points omitted:
a) I am using ios 13.2.2 on both iPhones
b) News pages have images and it is these that seem to take a lot of processing -hence battery discharge.

JezzerP · Nov 20, 2019

Not quite sure what your question is, or why you have to have an app running just in case your daughter contacts you? How does your daughter normally contact you? You don't have to have the Phone or Messages app running in the background for you to be reachable by these methods.

NSquirrel · Nov 21, 2019

Thanks for comment JezzerP.
It was not a question, as such, but an observation about unexpected battery drain, which is often a topic of postings.

To restate my observation:
-If you leave Safari launched when your phone goes to sleep, it may drain the battery via background refresh.
-This, I believe, occurs when Safari is left on a dynamic page, which updates with images - e.g. news pages
-Images, whether gifs, small embedded movies, or maybe even straight jpegs, incur processing power to scale to current window size and display, hence the battery drain.
-Incidentally such power hungry items maybe on a tab in the background of Safari
-If you close down Safari, before your phone goes to sleep, then this possible cause of battery drain is removed.

(As to why we leave one particular app sometimes launched, that is simply a personal preference, without going into details, but I close all other apps down when I have finished with them.)