I wrote about finding a if not the reason my iPhone’s battery was embarrassingly bad. Three days later I have to begrudgingly say that my phone almost feels new. The battery life is just that much better after I disabled Facebook Messenger’s Background App Refresh (BAR).
I ended up deleting Messenger because why did I need it when the Facebook app had that feature already? Well, it soon will not. So do keep in mind that disabling BAR for that app will likely help your battery stay more sane.
And you do not need BAR disabled for everything. It is a useful feature and when used right[ref]By the developer, not the user.[/ref] it makes the experience much better.