2017 Audi A4 / S4 — Owner's Manual
A lot of stress is placed on the battery when driving short distances, in traffic, and at cold times of the year. A lot of energy is used but little is generated. It is also critical when the engine is not running but electrical equipment is switched on. In this case, energy is used but none is generated.
In situations like this, energy management will actively regulate the distribution of energy. If you do not drive your vehicle for several days or weeks, electrical equipment is gradually scaled back or switched off. This reduces energy use and ensures the vehicle will be able to start after long periods of time. Some convenience functions, such as interior lighting or power seat adjustment, may not be available under certain circumstances.
These convenience functions will be available again once you switch the ignition on and start the engine. The battery will drain if you use Infotainment functions such as listening to the radio while the engine is switched off. If the vehicle's ability to start may be impaired by the energy use, a message will appear in the Infotainment system display. The message indicates that the system will switch off automatically soon.
If you would like to continue using the functions, you must start the engine.