BatteryManager.level

The BatteryManager.level property indicates the current battery charge level as a value between 0.0 and 1.0. A value of 0.0 means the battery is empty and the system is about to be suspended. A value of 1.0 means the battery is full. A value of 1.0 is also returned if the implementation isn't able to determine the battery charge level or if the system is not battery-powered. When its value changes, the levelchange event is fired.

Value

A number.

Examples

Getting the battery level

HTML

<button id="get-level">Get battery level</button>
<div id="output"></div>

JavaScript

const getLevel = document.querySelector('#get-level');
const output = document.querySelector('#output');

getLevel.addEventListener('click', async () => {
  if (!navigator.getBattery) {
    output.textContent = 'Battery manager is unsupported';
  } else {
    const manager = await navigator.getBattery();
    const level = manager.level;
    output.textContent = `Battery level: ${level}`;
  }
});

Result

Specifications

Specification
Battery Status API
# dom-batterymanager-level

Browser compatibility

BCD tables only load in the browser

See also