(January 5, 2010) General Motors is using the venue of the Consumer Electronics Show in Las Vegas to announce smartphone applications that will help Chevrolet Volt drivers to maximize their electric driving capability. GM hopes to leverage its established OnStar vehicle communications network to allow drivers to monitor and manage the battery charge using either the Apple iPhone, Motorola Droid or Blackberry Storm.
GM was one of the first automakers to introduce a system that allowed its vehicles to have two way communications with a central control system when it launched OnStar in 1995. The system began with basic functions such as automatic notification of emergency services in the event of an airbag activation and remote unlocking if the keys were left in the car. Since then GM has continually added new capabilities such as turn by turn directions without a navigation system, vehicle health reports and the ability to remotely slow a stolen vehicle.
Since the Chevrolet Volt program was launched as a concept in 2006, GM's goal has been for the battery to provide a nominal 40 mile electric driving range and last the life of the car. At the same time, the Volt was meant to be affordable to mainstream customers. That meant its lithium ion battery pack had to be both durable and at the same time be as small as possible to keep cost down.
In order to achieve these seemingly contradictory goals the battery management system is a critical part of making the car work. Whenever the car is plugged in, the temperature of the battery pack as well as the charging rate are carefully controlled. In order to maximize the range, the load on the battery while driving must be kept to a minimum.
The mobile phone applications will play an important part in helping the driver get the most out of the Volt. The application works on touch screen smart-phones using the same user interface regardless of the phone type. The interface mimics the gauge interface on the LCD instrument cluster inside the Volt itself. When the application is first loaded on the phone, it is authenticated to a specific car.
After launching the application, it automatically calls the OnStar servers over the 3G mobile broadband network. OnStar then connects the phone to the car it has been authenticated too allowing the driver to manage various features. Because utilities charge higher rates for electricity during peak usage periods during the day and less at night, the application allows drivers to set the car's charging system to a grid-friendly mode. This tells the car not to start charging until the off-peak rates kick in even if the car is plugged in earlier. Of course if the driver needs the car sooner, the charging can also be started immediately.
Of course the car can only be charged if it is plugged in. Here the OnStar connectivity again comes into play. Because the car sense whether it has been plugged in, it can notify OnStar when it is not. The driver can use the application to set an automatic notification if the car has not been plugged at a pre-set time. Thus if the notification is set for 8pm, and the driver has forgotten to plug in the car when they got home, it will send a message to the phone reminding them to plug in. In addition, if the charge coupler has been removed before the car is charged, it will automatically send a message to the phone. The driver can also use the application at any time to check the current state of charge of the battery.
One of the keys to maximizing electric range is reducing the loads on the battery. During winter or summer months, the use of climate control to heat or cool the car can significantly cut the range. A recent evaluation by Consumer Reports of the Mitsubishi i-MiEV during an early December cold snap saw the range cut by more than 50 percent when the heater was used.
Volt drivers will be able to use the mobile app to tell the car when they plan to leave and then set a desired interior temperature. The Volt can then calculate how long it will take to adjust the temperature based on current ambient conditions and either pre-heat or cool the interior while it is still plugged in and drawing grid power. Since it takes more energy to bring the temperature up or down than it does to maintain the temperature, this cuts the load on the battery. Range will still be reduced but not by as much.
A demonstration version of the application will be available for download to the supported phones soon after the announcement with a final version coming later in the year closer to the production launch. GM also plans to add support for more phones going forward.
