This feature is obsolete.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.

The getBattery() method provides information about the system's battery, returns a battery promise, which is resolved in a BatteryManager object providing also some new events you can handle to monitor the battery status.. This implements the Battery Status API; see that documentation for additional details, a guide to using the API, and sample code.


var batteryPromise = navigator.getBattery();

Return value

A Promise which, when resolved, calls its fulfillment handler with a single parameter: a BatteryManager object which you can use to get information about the battery's state.


This example fetches the current charging state of the battery and establishes a handler for the chargingchange event, so that the charging state is recorded whenever it changes.

let batteryIsCharging = false;

navigator.getBattery().then(function(battery) {
  batteryIsCharging = battery.charging;

  battery.addEventListener('chargingchange', function() {
    batteryIsCharging = battery.charging;

For more examples and details, see Battery Status API.


Specification Status Comment
Battery Status API
The definition of 'Navigator.getBattery()' in that specification.
Candidate Recommendation Initial definition

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 39 10 (10) moz
16 (16)[1]
43 (43)[2]
52 (52)[3]
No support 25 No support
Feature Android Webview Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 40 42

10.0 (10) moz
16.0 (16)[1]
43.0 (43)[2]
50.0 (50)[3]

No support 25 No support

[1] 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 the Battery API on Mac OS X is available starting with Gecko 18.0 (Firefox 18.0 / Thunderbird 18.0 / SeaMonkey 2.15). Firefox also provided support for the deprecated navigator.battery until Firefox 50.

[2] The new promise-based syntax for Navigator.getBattery() is supported from Firefox 43 onwards.

[3] From Firefox 52 onwards, the Battery Status API is only available in chrome/privileged code.

See also

Document Tags and Contributors

 Contributors to this page: jpmedley, chrisdavidmills, aranjedeath, Sheppy, maybe, cvrebert, teoli, franciov
 Last updated by: jpmedley,