About power management

The WVA has a configurable power management service. You can use the power management settings to control whether the WVA powers down ("sleeps") when the vehicle is not running, and choose from a variety of mechanisms for waking the WVA again. During the time the WVA is sleeping, its power consumption is dramatically reduced, which prevents the device from draining the vehicle battery.

When you enable power management, the WVA detects that the engine is not running, then waits a specified amount of time and goes to sleep. The specified time is configurable and can be delayed if there is an important operation on the vehicle. Instances where a delay would be desirable include:

• To allow a web services-based application to interact with the device (and, in a sense, the vehicle) for a certain period of time after no engine activity.
• To reduce the latency involved in responsiveness while the WVA boots if the vehicle is only shut off for a brief period. For example, if the vehicle were turned off and then back on quickly, such a delay could cause the WVA to avoid its own boot time by simply staying awake.

You can configure the WVA to wake under one or more of the following conditions:

• When a configurable timer expires.
• When the alternator is generating power.
• When the WVA detects sufficient vibration; for instance, slamming the driver door or starting the engine.
• When a user presses the WVA button.

The power management service is integrated with the standard device settings. There are two ways to configure these settings:

• Using the settings on the Power Management Configuration page. See Configure power management settings.
• Through the WVA web services. See Wireless Vehicle Bus Adapter Application Developer's Guide for more information on web services.