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.
Syntax
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.
Example
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.
Specifications
| Specification | Status | Comment |
|---|---|---|
| Battery Status API The definition of 'Navigator.getBattery()' in that specification. |
Candidate Recommendation | Initial definition |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 39.0 | 10 (10) moz 16 (16)[1] 43 (43)[2] 52 (52)[3] |
No support | 25 | No support |
| Feature | Android | Android Webview | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|
| Basic support | No support | 40.0 |
10.0 (10) moz |
No support | 25 | No support | 42.0 |
[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.