How to access the current battery status in an Ionic 4 / Angular + Cordova application?

Ionic Native
1

Goal

I would like to access the current battery status in an Ionic 4 / Angular + Cordova application.

What I have tried

I followed the instruction https://ionicframework.com/docs/native/battery-status on a clean blank Ionic 4 app.

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { RouteReuseStrategy } from '@angular/router';

import { IonicModule, IonicRouteStrategy } from '@ionic/angular';
import { SplashScreen } from '@ionic-native/splash-screen/ngx';
import { StatusBar } from '@ionic-native/status-bar/ngx';
import { BatteryStatus } from '@ionic-native/battery-status/ngx';

import { AppComponent } from './app.component';
import { AppRoutingModule } from './app-routing.module';

@NgModule({
  declarations: [AppComponent],
  entryComponents: [],
  imports: [BrowserModule, IonicModule.forRoot(), AppRoutingModule],
  providers: [
    StatusBar,
    SplashScreen,
    BatteryStatus,
    { provide: RouteReuseStrategy, useClass: IonicRouteStrategy }
  ],
  bootstrap: [AppComponent]
})
export class AppModule {}

home.page.ts

import { Component } from '@angular/core';
import { BatteryStatus } from '@ionic-native/battery-status/ngx';

@Component({
  selector: 'app-home',
  templateUrl: 'home.page.html',
  styleUrls: ['home.page.scss']
})
export class HomePage {
  constructor(private batteryStatus: BatteryStatus) {
    // watch change in battery status
    const subscription = this.batteryStatus.onChange().subscribe(status => {
      console.log(status.level, status.isPlugged);
    });
  }
}

The Problem

Sadly I always get the following error, anyone an idea what I’m doing wrong?

Error

ERROR TypeError: Invalid event target
    at setupSubscription (fromEvent.js:50)
    at Observable._subscribe (fromEvent.js:24)
    at Observable.push../node_modules/rxjs/_esm5/internal/Observable.js.Observable._trySubscribe (Observable.js:43)
    at Observable.push../node_modules/rxjs/_esm5/internal/Observable.js.Observable.subscribe (Observable.js:29)
    at new HomePage (home.page.ts:12)
    at createClass (core.js:22150)
    at createDirectiveInstance (core.js:22029)
    at createViewNodes (core.js:23255)
    at createRootView (core.js:23169)
    at callWithDebugContext (core.js:24177)
2

Does no one have an idea?