BatteryManager: levelchange event

Secure context

The levelchange event of the BatteryManager interface is fired when the battery level property is updated.

Syntax

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

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

onlevelchange = (event) => { }

Event type

A generic Event.

Example

HTML

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

JavaScript

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

Browser compatibility

See also

• BatteryManager
• getBattery()