Navigator: getBattery() method

{{ApiRef("Battery API")}}{{securecontext_header}}

The getBattery() method provides information about the system's battery. It returns a battery promise, which resolves with a {{domxref("BatteryManager")}} object providing some properties to get the battery status also some events you can handle to monitor the battery status. This implements the {{domxref("Battery Status API", "", "", "nocode")}}; see that documentation for additional details, a guide to using the API, and sample code.

Since Chrome 103, the Navigator.getBattery() method of {{domxref("Battery Status API", "", "", "nocode")}} only expose to secure context.

[!NOTE] Access to this feature may be controlled by the {{HTTPHeader("Permissions-Policy")}} directive {{HTTPHeader("Permissions-Policy/battery", "battery")}}.

Syntax

getBattery()

Parameters

None.

Return value

A {{JSxRef("Promise")}} that fulfills with a {{DOMxRef("BatteryManager")}} object which you can use to get information about the battery's state.

Exceptions

• NotAllowedError {{domxref("DOMException")}}

  • : Use of this feature was blocked by a Permissions Policy.

• SecurityError {{domxref("DOMException")}}

  • : The User Agent does not expose battery information to insecure contexts and this method was called from an insecure context.

Examples

This example fetches the current charging state of the battery and establishes a handler for the {{domxref("BatteryManager/chargingchange_event", "chargingchange")}} event, so that the charging state is recorded whenever it changes.

let batteryIsCharging = false;

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

  battery.addEventListener("chargingchange", () => {
    batteryIsCharging = battery.charging;
  });
});

For more examples and details, see {{domxref("Battery Status API", "", "", "nocode")}}.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("Battery Status API", "", "", "nocode")}}
• {{HTTPHeader("Permissions-Policy")}} {{HTTPHeader("Permissions-Policy/battery", "battery")}} directive