Indicates the amount of time, in seconds, that remains until the battery is fully discharged.

Even if the time returned is precise to the second, browsers round them to a higher interval (typically to the closest 15 minutes) for privacy reasons.


var time = battery.dischargingTime

On return, time is the remaining time in seconds until the battery, which is a BatteryManager object, is fully discharged and the system will suspend. This value is Infinity if the battery is currently charging rather than discharging, or if the system is unable to report the remaining discharging time.


HTML Content

<div id="dischargingTime">(discharging time unknown)</div>

JavaScript Content

navigator.getBattery().then(function(battery) {

    var time = battery.dischargingTime;

    document.querySelector('#dischargingTime').textContent = battery.dischargingTime;


Specification Status Comment
Battery Status API Candidate Recommendation Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 39.0 10 (10) moz
16 (16)[1][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
16.0 (16)[1][3]
No support 25[2] No support 42.0[2]

[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 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.

[2] Values for BatteryManager.chargingTime and BatteryManager.dischargingTime are always equal to Infinity.

[3] From Firefox 51, the actual precision is no more to the second, but to the nearest 15 minutes.

See also

Document Tags and Contributors

 Last updated by: teoli,