Just add battery-manager to your project via npm or yarn or pnpm. It helps you to check the client battery level using Web Battery API.
pnpm add battery-manager
Then it is ready to use example app:
import BatteryManager from 'battery-manager';
const manager = new BatteryManager({
onChargingChange: (isCharging) => { console.log(`Your laptop is ${isCharging ? 'charging' : 'not charging'}`) },
onLevelChange: (level) => { console.log(`Your laptop battery is ${level * 100}`) },
})
console.log('hello dude!');