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/DOM

BatteryManager.onlevelchange

Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

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 Content

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

JavaScript Content

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

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

Specifications

Specification	Status	Comment
Battery Status API	Candidate Recommendation	Initial definition

Browser compatibilityUpdate compatibility data on GitHub

	Desktop
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	38	?	16 — 52 16 — 52 10 — 16 Prefixed Prefixed Requires the vendor prefix: moz 52 Disabled Disabled by default in Firefox 10, but can be enabled setting the preference `dom.battery.enabled` to `true`. Starting with Firefox 11, `mozBattery` is enabled by default. The Battery API is currently supported on Android, Windows, and Linux with UPower installed. Support for MacOS is available starting with Firefox 18. Firefox also provide support for the deprecated `navigator.battery`. Disabled From version 52: this feature is behind the `dom.battery.enabled` preference. To change preferences in Firefox, visit about:config. 52 From this version onwards, the Battery Status API is only available in chrome/privileged code.	No	25	No

	Mobile
	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	iOS Safari	Samsung Internet
Basic support	40	38 38 Values for `BatteryManager.chargingTime` and `BatteryManager.dischargingTime` are always equal to `Infinity`.	No	10 — 16 Prefixed 10 — 16 Prefixed Prefixed Requires the vendor prefix: moz 16 — 52 Disabled Disabled by default in Firefox 10.0, but can be enabled setting the preference `dom.battery.enabled` to `true`. Starting with Firefox 11.0, `mozBattery` is enabled by default. The Battery API is currently supported on Android, Windows, and Linux with UPower installed. Support for MacOS is available starting with Gecko 18.0 (Firefox 18.0 / Thunderbird 18.0 / SeaMonkey 2.15). Firefox also provide support for the deprecated `navigator.battery`. Disabled From version 16 until version 52 (exclusive): this feature is behind the `dom.battery.enabled` preference. To change preferences in Firefox, visit about:config. 52 From this version onwards, the Battery Status API is only available in chrome/privileged code.	25	? — ?	Yes