awesome-cordova-plugins/src/@ionic-native/plugins/battery-status/index.ts

import { Injectable } from '@angular/core';
import { Cordova, IonicNativePlugin, Plugin } from '@ionic-native/core';
import { Observable } from 'rxjs/Observable';

export interface BatteryStatusResponse {
  /**
   * The battery charge percentage
   */
  level: number;

  /**
   * A boolean that indicates whether the device is plugged in
   */
  isPlugged: boolean;
}

/**
 * @name Battery Status
 * @description
 * Requires Cordova plugin: cordova-plugin-batterystatus. For more info, please see the [BatteryStatus plugin docs](https://github.com/apache/cordova-plugin-battery-status).
 *
 * @usage
 * ```typescript
 * import { BatteryStatus } from '@ionic-native/battery-status';
 *
 * constructor(private batteryStatus: BatteryStatus) { }
 *
 * ...
 *
 *
 * // watch change in battery status
 * const subscription = this.batteryStatus.onChange().subscribe(status => {
 *    console.log(status.level, status.isPlugged);
 * });
 *
 * // stop watch
 * subscription.unsubscribe();
 *
 * ```
 * @interfaces
 * BatteryStatusResponse
 */
@Plugin({
  pluginName: 'BatteryStatus',
  plugin: 'cordova-plugin-battery-status',
  pluginRef: 'navigator.battery',
  repo: 'https://github.com/apache/cordova-plugin-battery-status',
  platforms: ['iOS', 'Android', 'Windows', 'Browser']
})
@Injectable()
export class BatteryStatus extends IonicNativePlugin {
  /**
   * Watch the change in battery level
   * @returns {Observable<BatteryStatusResponse>} Returns an observable that pushes a status object
   */
  @Cordova({
    eventObservable: true,
    event: 'batterystatus'
  })
  onChange(): Observable<BatteryStatusResponse> {
    return;
  }

  /**
   * Watch when the battery level goes low
   * @returns {Observable<BatteryStatusResponse>} Returns an observable that pushes a status object
   */
  @Cordova({
    eventObservable: true,
    event: 'batterylow'
  })
  onLow(): Observable<BatteryStatusResponse> {
    return;
  }

  /**
   * Watch when the battery level goes to critial
   * @returns {Observable<BatteryStatusResponse>} Returns an observable that pushes a status object
   */
  @Cordova({
    eventObservable: true,
    event: 'batterycritical'
  })
  onCritical(): Observable<BatteryStatusResponse> {
    return;
  }
}