In one aspect, a method includes maintaining a list of future user events. The list includes a field associated with each of the future user events to indicate whether charging of a mobile device is possible during a respective future user event. The method also includes receiving user input indicating whether charging of the mobile device is possible during at least one of the future user events and updating the field associated with the future user events based on the user input. Also included in the method is setting a battery charging threshold based on one or more of the future user events and based on the fields associated with the future user events. An alert may then be generated prior to a future user event in response to a current battery level of the mobile device being less than the battery charging threshold.