BatteryManager.onlevelchange

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The BatteryManager.onlevelchange property specifies an event listener to receive levelchange events. These events occur when the battery level is updated.

Syntax

navigator.battery.onlevelchange = funcRef

Where battery is a BatteryManager object, and funcRef is a function to be called when the levelchange event occurs.

Example

HTML

<div id="level">(battery level unknown)</div>
<div id="stateBattery">(charging state unknown)</div>

JavaScript

navigator.getBattery().then(function(battery) {
  battery.onlevelchange = function(){
    document.querySelector('#level').textContent = battery.level;

    if(battery.charging) {
      document.querySelector('#stateBattery').textContent =
          "Charging time: " + (battery.chargingTime / 60);
    }
    else {
      document.querySelector('#stateBattery').textContent =
          "Discharging time: " + (battery.dischargingTime / 60);
    }
  };
});

Specifications

Specification
Battery Status API # dom-batterymanager-onlevelchange

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`onlevelchange`	38	79	43-52	No	25	No	38	38	43-52	25	No	3.0