artesanias/node_modules/localforage/bower_components/modernizr/feature-detects/battery-level.js

// Low Battery Level
// Enable a developer to remove CPU intensive CSS/JS when battery is low
// developer.mozilla.org/en/DOM/window.navigator.mozBattery
// By: Paul Sayre

Modernizr.addTest('lowbattery', function () {
	var minLevel = 0.20,
		battery = Modernizr.prefixed('battery', navigator);
	return !!(battery && !battery.charging && battery.level <= minLevel);
});