BatteryManager: level property
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The level read-only property of the BatteryManager interface 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 or the user agent is unable to report the battery status information.
When its value changes, the levelchange event is fired.
Value
A number.
Examples
Getting the battery level
HTML
html
<button id="get-level">Get battery level</button>
<div id="output"></div>
JavaScript
js
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
| desktop | mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
level
|
|
|
|
|
|
|
|
|
|
|
|
|
Legend
Tip: you can click/tap on a cell for more information.
- Full support
- Full support
- No support
- No support