BatteryManager: levelchange event

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The levelchange event of the Battery Status API is fired when the battery level property is updated.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("levelchange", (event) => { })

onlevelchange = (event) => { }

Event type

A generic Event.

Example

HTML

html
<div id="level">(battery level unknown)</div>
<div id="stateBattery">(charging state unknown)</div>

JavaScript

js
navigator.getBattery().then((battery) => {
  battery.onlevelchange = () => {
    document.querySelector("#level").textContent = battery.level;

    if (battery.charging) {
      document.querySelector("#stateBattery").textContent = `Charging time: ${
        battery.chargingTime / 60
      }`;
    } else {
      document.querySelector("#stateBattery").textContent =
        `Discharging time: ${battery.dischargingTime / 60}`;
    }
  };
});

Specifications

Specification
Battery Status API
# ref-for-dfn-levelchange-1
Battery Status API
# dom-batterymanager-onlevelchange

Browser compatibility

BCD tables only load in the browser

See also