diff --git a/src/main/angular/src/app/app.html b/src/main/angular/src/app/app.html
index 8f78f8b..e5e0c41 100644
--- a/src/main/angular/src/app/app.html
+++ b/src/main/angular/src/app/app.html
@@ -20,16 +20,12 @@
   </div>
 </div>
 
-@if (ws.connected) {
-
-  <div class="MainMenuDrawer NoUserSelect" [hidden]="!showDrawer">
-    @for (location of locationList; track location.id) {
-      @if (location.id !== locationService.id) {
-        <div class="MainMenuItem" (click)="navigate(`Location/${location.id}`); showDrawer = false" routerLinkActive="MainMenuItemActive">{{ location.name }}</div>
-      }
+<div class="MainMenuDrawer NoUserSelect" [hidden]="!showDrawer">
+  @for (location of locationList; track location.id) {
+    @if (location.id !== menuService.locationId) {
+      <div class="MainMenuItem" (click)="navigate(`Location/${location.id}`); showDrawer = false" routerLinkActive="MainMenuItemActive">{{ location.name }}</div>
     }
-  </div>
-
-}
+  }
+</div>
 
 <router-outlet/>
diff --git a/src/main/angular/src/app/app.ts b/src/main/angular/src/app/app.ts
index 00b13bc..2a582f3 100644
--- a/src/main/angular/src/app/app.ts
+++ b/src/main/angular/src/app/app.ts
@@ -1,4 +1,4 @@
-import {Component, OnDestroy, OnInit} from '@angular/core';
+import {Component, OnInit} from '@angular/core';
 import {Router, RouterLink, RouterLinkActive, RouterOutlet} from '@angular/router';
 import {FaIconComponent} from '@fortawesome/angular-fontawesome';
 import {faBars, faGears} from '@fortawesome/free-solid-svg-icons';
@@ -14,7 +14,7 @@ import {faHome} from '@fortawesome/free-regular-svg-icons';
   templateUrl: './app.html',
   styleUrl: './app.less'
 })
-export class App implements OnInit, OnDestroy {
+export class App implements OnInit {
 
   protected readonly faHome = faHome;
 
@@ -39,11 +39,6 @@ export class App implements OnInit, OnDestroy {
 
   ngOnInit(): void {
     this.locationService.findAll(list => this.locationList = list);
-    this.menuService.title = "Orte";
-  }
-
-  ngOnDestroy(): void {
-    this.menuService.title = "";
   }
 
   navigate(url: string): void {
diff --git a/src/main/angular/src/app/location/Location.ts b/src/main/angular/src/app/location/Location.ts
index da420b6..836bcae 100644
--- a/src/main/angular/src/app/location/Location.ts
+++ b/src/main/angular/src/app/location/Location.ts
@@ -1,66 +1,26 @@
 import {or, validateNumber, validateString} from '../common';
 import {Series} from '../series/Series';
-import {Value} from '../series/Value';
 
 export class Location {
 
-  powerSelf: Value = Value.NULL;
-
-  powerPurchasePercentConsume: Value = Value.NULL;
-
-  powerProducePercentConsume: Value = Value.NULL;
-
-  powerDeliveryPercentConsume: Value = Value.NULL;
-
-  powerDeliveryPercentProduce: Value = Value.NULL;
-
-  powerSelfPercentConsume: Value = Value.NULL;
-
-  powerSelfPercentProduce: Value = Value.NULL;
-
   constructor(
     readonly id: number,
     readonly name: string,
     readonly latitude: number,
     readonly longitude: number,
-    private _energyPurchase: Series | null,
-    private _energyDeliver: Series | null,
-    private _energyProduce: Series | null,
-    private _powerPurchase: Series | null,
-    private _powerDeliver: Series | null,
-    private _powerProduce: Series | null,
-    private _outsideTemperature: Series | null,
-    private _outsideHumidityRelative: Series | null,
-    private _outsideHumidityAbsolute: Series | null,
-    private _powerConsume: Value = Value.NULL,
+    readonly energyPurchase: Series | null,
+    readonly energyDeliver: Series | null,
+    readonly energyProduce: Series | null,
+    readonly powerPurchase: Series | null,
+    readonly powerDeliver: Series | null,
+    readonly powerProduce: Series | null,
+    readonly outsideTemperature: Series | null,
+    readonly outsideHumidityRelative: Series | null,
+    readonly outsideHumidityAbsolute: Series | null,
   ) {
-    this.updateConsume();
+    //
   }
 
-  readonly updateSeries = (series: Series) => {
-    if (series.equals(this._energyPurchase)) {
-      this._energyPurchase = series;
-    }
-    if (series.equals(this._energyDeliver)) {
-      this._energyDeliver = series;
-    }
-    if (series.equals(this._energyProduce)) {
-      this._energyProduce = series;
-    }
-    if (series.equals(this._powerProduce)) {
-      this._powerProduce = series;
-      this.updateConsume();
-    }
-    if (series.equals(this._powerPurchase)) {
-      this._powerPurchase = series;
-      this.updateConsume();
-    }
-    if (series.equals(this._powerDeliver)) {
-      this._powerDeliver = series;
-      this.updateConsume();
-    }
-  };
-
   static fromJson(json: any): Location {
     return new Location(
       validateNumber(json.id),
@@ -79,55 +39,18 @@ export class Location {
     );
   }
 
-  private updateConsume() {
-    this._powerConsume = Value.ZERO.plus(this._powerPurchase?.value, true).plus(this._powerProduce?.value, true).minus(this._powerDeliver?.value, true);
-    this.powerSelf = Value.ZERO.plus(this.powerProduce?.value.minus(this.powerDeliver?.value, true), true);
-    this.powerPurchasePercentConsume = Value.ZERO.plus(this.powerPurchase?.value.percent(this.powerConsume, "%", 0), true);
-    this.powerProducePercentConsume = Value.ZERO.plus(this.powerProduce?.value.percent(this.powerConsume, "%", 0), true);
-    this.powerDeliveryPercentConsume = Value.ZERO.plus(this.powerDeliver?.value.percent(this.powerConsume, "%", 0), true);
-    this.powerDeliveryPercentProduce = Value.ZERO.plus(this.powerDeliver?.value.percent(this.powerProduce?.value, "%", 0), true);
-    this.powerSelfPercentConsume = Value.ZERO.plus(this.powerSelf.percent(this.powerConsume, "%", 0), true);
-    this.powerSelfPercentProduce = Value.ZERO.plus(this.powerSelf.percent(this.powerProduce?.value, "%", 0), true);
-  }
-
-  get energyPurchase(): Series | null {
-    return this._energyPurchase;
-  }
-
-  get energyDeliver(): Series | null {
-    return this._energyDeliver;
-  }
-
-  get energyProduce(): Series | null {
-    return this._energyProduce;
-  }
-
-  get powerPurchase(): Series | null {
-    return this._powerPurchase;
-  }
-
-  get powerDeliver(): Series | null {
-    return this._powerDeliver;
-  }
-
-  get powerProduce(): Series | null {
-    return this._powerProduce;
-  }
-
-  get powerConsume(): Value | null {
-    return this._powerConsume;
-  }
-
-  get outsideTemperature(): Series | null {
-    return this._outsideTemperature;
-  }
-
-  get outsideHumidityRelative(): Series | null {
-    return this._outsideHumidityRelative;
-  }
-
-  get outsideHumidityAbsolute(): Series | null {
-    return this._outsideHumidityAbsolute;
+  getSeries(): Series[] {
+    return [
+      this.energyPurchase,
+      this.energyDeliver,
+      this.energyProduce,
+      this.powerPurchase,
+      this.powerDeliver,
+      this.powerProduce,
+      this.outsideTemperature,
+      this.outsideHumidityRelative,
+      this.outsideHumidityAbsolute,
+    ].filter(s => s) as Series[];
   }
 
 }
diff --git a/src/main/angular/src/app/location/detail/location-detail.ts b/src/main/angular/src/app/location/detail/location-detail.ts
index 57ddc6c..5844cbf 100644
--- a/src/main/angular/src/app/location/detail/location-detail.ts
+++ b/src/main/angular/src/app/location/detail/location-detail.ts
@@ -56,6 +56,8 @@ export class LocationDetail implements OnInit, OnDestroy {
 
   protected readonly Math = Math;
 
+  private locationId: number | null = null;
+
   protected location: Location | null = null;
 
   private readonly subs: Subscription [] = [];
@@ -85,19 +87,22 @@ export class LocationDetail implements OnInit, OnDestroy {
         this.router.navigate(["Location/" + this.configService.locationId]);
         return;
       }
-      setTimeout(() => this.locationService.id = id, 0);
+      this.locationId = id;
+      if (this.locationId) {
+        this.locationService.getById(this.locationId, this.onLocationChange);
+      }
     }));
-    this.subs.push(this.locationService.location$.subscribe(this.onLocationChange));
+    this.subs.push(this.locationService.subscribe(this.onLocationChange));
   }
 
   private readonly onLocationChange = (location: Location | null): void => {
-    this.location = location;
-    this.menuService.title = this.location?.name || "";
+    if (this.locationId === location?.id) {
+      this.location = location;
+      this.menuService.setLocation(location);
+    }
   };
 
   ngOnDestroy(): void {
-    this.location = null;
-    this.menuService.title = "";
     this.subs.forEach(sub => sub.unsubscribe());
     this.subs.length = 0;
   }
diff --git a/src/main/angular/src/app/location/energy/charts/energy-charts.ts b/src/main/angular/src/app/location/energy/charts/energy-charts.ts
index 2b9fb6b..97ec0f8 100644
--- a/src/main/angular/src/app/location/energy/charts/energy-charts.ts
+++ b/src/main/angular/src/app/location/energy/charts/energy-charts.ts
@@ -1,4 +1,4 @@
-import {Component, Inject, Input, LOCALE_ID, OnChanges, SimpleChanges, ViewChild} from '@angular/core';
+import {Component, Inject, Input, LOCALE_ID, OnChanges, ViewChild} from '@angular/core';
 import {Interval} from '../../../series/Interval';
 import {PointService} from '../../../point/point-service';
 import {Location} from '../../Location';
@@ -111,6 +111,8 @@ export class EnergyCharts implements OnChanges {
     },
   };
 
+  private refreshTimeout: number | undefined;
+
   constructor(
     readonly pointService: PointService,
     @Inject(LOCALE_ID) readonly locale: string,
@@ -118,8 +120,10 @@ export class EnergyCharts implements OnChanges {
     //
   }
 
-  ngOnChanges(changes: SimpleChanges): void {
-    console.log("ngOnChanges", changes);
+  ngOnChanges(): void {
+    clearTimeout(this.refreshTimeout);
+    this.refreshTimeout = setTimeout(() => this.ngOnChanges(), 60 * 1000);
+
     const series = [
       this.location.energyPurchase,
       this.location.energyDeliver,
diff --git a/src/main/angular/src/app/location/energy/location-energy.ts b/src/main/angular/src/app/location/energy/location-energy.ts
index bb1a19a..83f9d38 100644
--- a/src/main/angular/src/app/location/energy/location-energy.ts
+++ b/src/main/angular/src/app/location/energy/location-energy.ts
@@ -93,6 +93,7 @@ export class LocationEnergy implements OnInit, OnChanges, OnDestroy {
 
   ngOnDestroy(): void {
     this.subs.forEach(sub => sub.unsubscribe());
+    this.subs.length = 0;
   }
 
   protected readonly update = (fresh: Series): void => {
@@ -109,12 +110,12 @@ export class LocationEnergy implements OnInit, OnChanges, OnDestroy {
       next(value);
       this.consume = this.purchase.plus(this.produce, true).minus(this.deliver, true);
       this.self = this.produce.minus(this.deliver, true);
-      this.purchasePercentConsume = this.purchase.percent(this.consume, "%", 0);
-      this.producePercentConsume = this.produce.percent(this.consume, "%", 0);
-      this.deliveryPercentConsume = this.deliver.percent(this.consume, "%", 0);
-      this.deliveryPercentProduce = this.deliver.percent(this.produce, "%", 0);
-      this.selfPercentConsume = this.self.percent(this.consume, "%", 0);
-      this.selfPercentProduce = this.self.percent(this.produce, "%", 0);
+      this.purchasePercentConsume = this.purchase.percent(this.consume);
+      this.producePercentConsume = this.produce.percent(this.consume);
+      this.deliveryPercentConsume = this.deliver.percent(this.consume);
+      this.deliveryPercentProduce = this.deliver.percent(this.produce);
+      this.selfPercentConsume = this.self.percent(this.consume);
+      this.selfPercentProduce = this.self.percent(this.produce);
     };
     if (fresh !== null && fresh !== undefined) {
       if (fresh.id !== series?.id) {
diff --git a/src/main/angular/src/app/location/location-service.ts b/src/main/angular/src/app/location/location-service.ts
index b4f23ca..44cd61b 100644
--- a/src/main/angular/src/app/location/location-service.ts
+++ b/src/main/angular/src/app/location/location-service.ts
@@ -1,50 +1,17 @@
 import {Injectable} from '@angular/core';
 import {ApiService, CrudService, Next, WebsocketService} from '../common';
 import {Location} from './Location'
-import {SeriesService} from '../series/series-service';
-import {BehaviorSubject, Observable} from 'rxjs';
 
 @Injectable({
   providedIn: 'root'
 })
 export class LocationService extends CrudService<Location> {
 
-  private readonly _location = new BehaviorSubject<Location | null>(null);
-
-  private _id: number | null = null;
-
   constructor(
     api: ApiService,
     ws: WebsocketService,
-    readonly seriesService: SeriesService,
   ) {
     super(api, ws, ['Location'], Location.fromJson);
-    this.seriesService.subscribe(series => this._location.value?.updateSeries(series));
-    this.ws.onConnect(this.fetch);
-    this.ws.onDisconnect(() => this._location.next(null));
-  }
-
-  set id(id: number | null) {
-    if (this._id !== id) {
-      this._id = id;
-      this.fetch();
-    }
-  }
-
-  get id(): number | null {
-    return this._id;
-  }
-
-  private readonly fetch = () => {
-    if (this._id === null) {
-      this._location.next(null);
-    } else {
-      this.getById(this._id, location => this._location.next(location));
-    }
-  };
-
-  get location$(): Observable<Location | null> {
-    return this._location.asObservable();
   }
 
   findAll(next: Next<Location[]>) {
diff --git a/src/main/angular/src/app/location/power/location-power.html b/src/main/angular/src/app/location/power/location-power.html
index d7e2ad1..4170907 100644
--- a/src/main/angular/src/app/location/power/location-power.html
+++ b/src/main/angular/src/app/location/power/location-power.html
@@ -11,11 +11,11 @@
         Bezug
       </div>
       <div class="SectionBody COLOR_FONT_PURCHASE">
-        {{ location.powerPurchase?.value?.toValueString(dateService.now) }}
+        {{ powerPurchase.toValueString(dateService.now) }}
       </div>
       @if (configService.energyPercent) {
         <div class="SectionBody COLOR_FONT_PURCHASE percent">
-          {{ location.powerPurchasePercentConsume.toValueString(dateService.now) }}
+          {{ powerPurchasePercentConsume.toValueString(dateService.now) }}
           <sub class="subscript">Verbrauch</sub>
         </div>
       }
@@ -26,11 +26,11 @@
         Solar
       </div>
       <div class="SectionBody COLOR_FONT_PRODUCE">
-        {{ location.powerProduce?.value?.toValueString(dateService.now) }}
+        {{ powerProduce.toValueString(dateService.now) }}
       </div>
       @if (configService.energyPercent) {
         <div class="SectionBody COLOR_FONT_PRODUCE percent">
-          {{ location.powerProducePercentConsume.toValueString(dateService.now) }}
+          {{ powerProducePercentConsume.toValueString(dateService.now) }}
           <sub class="subscript">Verbrauch</sub>
         </div>
       }
@@ -41,15 +41,15 @@
         Selbst
       </div>
       <div class="SectionBody COLOR_FONT_SELF">
-        {{ location.powerSelf.toValueString(dateService.now) }}
+        {{ powerSelf.toValueString(dateService.now) }}
       </div>
       @if (configService.energyPercent) {
         <div class="SectionBody COLOR_FONT_SELF percent">
-          {{ location.powerSelfPercentConsume.toValueString(dateService.now) }}
+          {{ powerSelfPercentConsume.toValueString(dateService.now) }}
           <sub class="subscript">Verbrauch</sub>
         </div>
         <div class="SectionBody COLOR_FONT_SELF percent">
-          {{ location.powerSelfPercentProduce.toValueString(dateService.now) }}
+          {{ powerSelfPercentProduce.toValueString(dateService.now) }}
           <sub class="subscript">Produktion</sub>
         </div>
       }
@@ -60,7 +60,7 @@
         Verbrauch
       </div>
       <div class="SectionBody COLOR_FONT_CONSUME">
-        {{ location.powerConsume?.toValueString(dateService.now) }}
+        {{ powerConsume.toValueString(dateService.now) }}
       </div>
     </div>
 
@@ -69,15 +69,15 @@
         Einspeisung
       </div>
       <div class="SectionBody COLOR_FONT_DELIVER">
-        {{ location.powerDeliver?.value?.toValueString(dateService.now) }}
+        {{ powerDeliver.toValueString(dateService.now) }}
       </div>
       @if (configService.energyPercent) {
         <div class="SectionBody COLOR_FONT_DELIVER percent">
-          {{ location.powerDeliveryPercentConsume.toValueString(dateService.now) }}
+          {{ powerDeliverPercentConsume.toValueString(dateService.now) }}
           <sub class="subscript">Verbrauch</sub>
         </div>
         <div class="SectionBody COLOR_FONT_DELIVER percent">
-          {{ location.powerDeliveryPercentProduce.toValueString(dateService.now) }}
+          {{ powerDeliverPercentProduce.toValueString(dateService.now) }}
           <sub class="subscript">Produktion</sub>
         </div>
       }
diff --git a/src/main/angular/src/app/location/power/location-power.ts b/src/main/angular/src/app/location/power/location-power.ts
index 555de35..13fc91e 100644
--- a/src/main/angular/src/app/location/power/location-power.ts
+++ b/src/main/angular/src/app/location/power/location-power.ts
@@ -1,7 +1,11 @@
-import {Component, Input} from '@angular/core';
+import {Component, Input, OnChanges, OnDestroy, OnInit} from '@angular/core';
 import {Location} from '../Location';
 import {DateService} from '../../date.service';
 import {ConfigService} from '../../config.service';
+import {Value} from '../../series/Value';
+import {SeriesService} from '../../series/series-service';
+import {Subscription} from 'rxjs';
+import {Series} from '../../series/Series';
 
 @Component({
   selector: 'app-location-power',
@@ -9,16 +13,86 @@ import {ConfigService} from '../../config.service';
   templateUrl: './location-power.html',
   styleUrl: './location-power.less',
 })
-export class LocationPower {
+export class LocationPower implements OnInit, OnChanges, OnDestroy {
 
   @Input()
   location!: Location;
 
+  private readonly subs: Subscription[] = [];
+
+  protected energyPurchase: Value = Value.NULL;
+
+  protected energyDeliver: Value = Value.NULL;
+
+  protected energyProduce: Value = Value.NULL;
+
+  protected powerPurchase: Value = Value.NULL;
+
+  protected powerDeliver: Value = Value.NULL;
+
+  protected powerProduce: Value = Value.NULL;
+
+  protected outsideTemperature: Value = Value.NULL;
+
+  protected outsideHumidityRelative: Value = Value.NULL;
+
+  protected outsideHumidityAbsolute: Value = Value.NULL;
+
+  protected powerConsume: Value = Value.NULL;
+
+  protected powerSelf: Value = Value.NULL;
+
+  protected powerPurchasePercentConsume: Value = Value.NULL;
+
+  protected powerProducePercentConsume: Value = Value.NULL;
+
+  protected powerDeliverPercentConsume: Value = Value.NULL;
+
+  protected powerDeliverPercentProduce: Value = Value.NULL;
+
+  protected powerSelfPercentConsume: Value = Value.NULL;
+
+  protected powerSelfPercentProduce: Value = Value.NULL;
+
   constructor(
     readonly dateService: DateService,
     readonly configService: ConfigService,
+    readonly seriesService: SeriesService,
   ) {
     //
   }
 
+  ngOnInit(): void {
+    this.subs.push(this.seriesService.subscribe(this.seriesUpdate));
+  }
+
+  ngOnChanges(): void {
+    this.location.getSeries().forEach(this.seriesUpdate);
+  }
+
+  ngOnDestroy(): void {
+    this.subs.forEach(sub => sub.unsubscribe());
+    this.subs.length = 0;
+  }
+
+  private readonly seriesUpdate = (series: Series): void => {
+    if (series.id === this.location.energyPurchase?.id) this.energyPurchase = series.value;
+    if (series.id === this.location.energyDeliver?.id) this.energyDeliver = series.value;
+    if (series.id === this.location.energyProduce?.id) this.energyProduce = series.value;
+    if (series.id === this.location.powerPurchase?.id) this.powerPurchase = series.value;
+    if (series.id === this.location.powerDeliver?.id) this.powerDeliver = series.value;
+    if (series.id === this.location.powerProduce?.id) this.powerProduce = series.value;
+    if (series.id === this.location.outsideTemperature?.id) this.outsideTemperature = series.value;
+    if (series.id === this.location.outsideHumidityRelative?.id) this.outsideHumidityRelative = series.value;
+    if (series.id === this.location.outsideHumidityAbsolute?.id) this.outsideHumidityAbsolute = series.value;
+    this.powerSelf = Value.ZERO.plus(this.powerProduce).minus(this.powerDeliver);
+    this.powerConsume = Value.ZERO.plus(this.powerPurchase).plus(this.powerSelf);
+    this.powerPurchasePercentConsume = this.powerPurchase.percent(this.powerConsume);
+    this.powerProducePercentConsume = this.powerProduce.percent(this.powerConsume);
+    this.powerDeliverPercentConsume = this.powerDeliver.percent(this.powerConsume)
+    this.powerDeliverPercentProduce = this.powerDeliver.percent(this.powerProduce)
+    this.powerSelfPercentConsume = this.powerSelf.percent(this.powerConsume);
+    this.powerSelfPercentProduce = this.powerSelf.percent(this.powerProduce);
+  };
+
 }
diff --git a/src/main/angular/src/app/menu-service.ts b/src/main/angular/src/app/menu-service.ts
index 1107f68..b816036 100644
--- a/src/main/angular/src/app/menu-service.ts
+++ b/src/main/angular/src/app/menu-service.ts
@@ -1,18 +1,31 @@
 import {Injectable} from '@angular/core';
+import {Location} from './location/Location';
 
 @Injectable({
   providedIn: 'root'
 })
 export class MenuService {
 
+  private _locationId: number | null = null;
+
   private _title: string = "";
 
+  get locationId(): number | null {
+    return this._locationId;
+  }
+
   get title(): string {
     return this._title;
   }
 
-  set title(value: string) {
-    setTimeout(() => this._title = value, 0);
+  setLocation(location: Location): void {
+    this._locationId = location.id;
+    this._title = location.name;
+  }
+
+  setNonLocation(title: string) {
+    this._title = title;
+    this._locationId = null;
   }
 
 }
diff --git a/src/main/angular/src/app/series/SeriesListResponse.ts b/src/main/angular/src/app/series/SeriesListResponse.ts
new file mode 100644
index 0000000..ad3cd61
--- /dev/null
+++ b/src/main/angular/src/app/series/SeriesListResponse.ts
@@ -0,0 +1,22 @@
+import {Series} from "./Series";
+import {validateList} from "../common";
+
+export class SeriesListResponse {
+
+  constructor(
+    readonly series: Series[]
+  ) {
+    //
+  }
+
+  static fromJson(json: any): SeriesListResponse {
+    return new SeriesListResponse(
+      validateList(json, Series.fromJson),
+    );
+  }
+
+  findSeries(series: Series | null): Series | null {
+    return series ? this.series.filter(s => s.id === series.id)[0] || null : null;
+  }
+
+}
diff --git a/src/main/angular/src/app/series/Value.ts b/src/main/angular/src/app/series/Value.ts
index 0aa736f..bb33e7b 100644
--- a/src/main/angular/src/app/series/Value.ts
+++ b/src/main/angular/src/app/series/Value.ts
@@ -29,7 +29,7 @@ export class Value {
       return `--- ${this.unit}`
     }
     const scale = Math.floor(Math.log10(this.value));
-    if(isNaN(scale)) {
+    if (isNaN(scale)) {
       return '0';
     }
     const rest = scale - this.precision + 1;
@@ -39,14 +39,14 @@ export class Value {
     return formatNumber(this.value, "de-DE", `0.${-rest}-${-rest}`) + ' ' + this.unit;
   }
 
-  plus(other: Value | null | undefined, nullToZero: boolean): Value {
+  plus(other: Value | null | undefined, nullToZero: boolean = true): Value {
     if (!nullToZero && (other === null || other === undefined)) {
       return Value.NULL;
     }
     return new BiValue(this, other || Value.ZERO, (a, b) => a + b);
   }
 
-  minus(other: Value | null | undefined, nullToZero: boolean): Value {
+  minus(other: Value | null | undefined, nullToZero: boolean = true): Value {
     if (!nullToZero && (other === null || other === undefined)) {
       return Value.NULL;
     }
@@ -86,11 +86,11 @@ export class Value {
     return ageSeconds > this.seconds * 2.1;
   }
 
-  percent(other: Value | null | undefined, unit: string | null = null, precision: number | null = null): Value {
+  percent(other: Value | null | undefined): Value {
     if (other === null || other === undefined) {
       return Value.NULL;
     }
-    return new BiValue(this, other, (a, b) => a / b * 100, unit, precision);
+    return new BiValue(this, other, (a, b) => a / b * 100, '%', 0);
   }
 
 }
diff --git a/src/main/angular/src/app/settings/settings-component.ts b/src/main/angular/src/app/settings/settings-component.ts
index 3e267d9..9acf542 100644
--- a/src/main/angular/src/app/settings/settings-component.ts
+++ b/src/main/angular/src/app/settings/settings-component.ts
@@ -1,6 +1,5 @@
 import {Component, OnInit} from '@angular/core';
 import {LocationSelect} from '../location/select/location-select';
-import {LocationService} from '../location/location-service';
 import {Location} from '../location/Location'
 import {ConfigService} from '../config.service';
 import {FormsModule} from '@angular/forms';
@@ -22,7 +21,6 @@ export class SettingsComponent implements OnInit {
   protected location: Location | null = null;
 
   constructor(
-    readonly locationService: LocationService,
     readonly configService: ConfigService,
     readonly menuService: MenuService,
   ) {
@@ -30,7 +28,7 @@ export class SettingsComponent implements OnInit {
   }
 
   ngOnInit(): void {
-    this.menuService.title = "Einstellungen";
+    this.menuService.setNonLocation("Einstellungen");
   }
 
 }