AngularJS: page reloading resets cached variable to null

I have two controllers that need to access a shared variable, which is done through a service component in AngularJS:

angular.module('app').service('cacheService', cacheService);

cacheService.$inject = ['$q'];

function cacheService($q) {
  this.sharedVariable = null;

  this.getValue = function() {
     return this.sharedVariable;
   }

  this.setValue = function(newVal) {
     this.sharedVariable = newVal;
   }
}

This service component works well in sharing the value between two controllers, however, when the page is reloaded/refreshed, the shared variable cannot keep the value. I am wondering if I should use the local storage in browsers to cache the variable value.