Obsolete since Gecko 50 (Firefox 50 / Thunderbird 50 / SeaMonkey 2.47)
This feature is obsolete.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 battery read-only property returns a BatteryManagerprovides information about the system's battery charge level; provides 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.

The battery property has been removed in favor of the standard Navigator.getBattery() method, which returns a battery Promise. Its support is still partial though.


var battery = navigator.battery;


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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 38.0 10 (10) moz[1]
16 (16)[2]
50 (50)[3]
No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? 38.0 10.0 (10) moz[1]
16.0 (16)[2]
50.0 (50)[3]
No support No support 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.

[2] 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).

[3] Removed in Firefox 50, in favor of navigator.getBattery().

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Battery Battery API Device API Navigator Non-Standard Non-standard Obsolete Property Reference