How To Check Low Battery Mode Setting While App Is In Background

Question

My app has functionality that works while the device is in the background. I've come across a problem where I need to change functionality if the user turns off/on Low Power Mode, but I'm not sure how to do this if the app is in the background. Is there a way to check the state of the Low Power Mode setting every time it is changed while the app is in the background?

This is the code I want to use for checking Low Power Mode:

if NSProcessInfo.processInfo().lowPowerModeEnabled {
    // Low Power functionality
} else {
    // Normal functionality
}