Re: Does the Phaeton use a single standard 12V battery? (av_audi)
Here's a bit of additional information, with photos. The vehicle power supply battery (the one on the left) is the larger of the two, except on the V10 TDI, which has an equally large battery for the starter. In the past, both the W12 and V8 were fitted with an 85 Ah / 480 A vehicle power supply battery, and a 61 Ah / 330 A starter battery. A 75 Ah / 420 A vehicle power supply battery is being phased in on new production V8's.
The starter battery only provides power for starting the car (and associated relays and electronics involved in the start process), it is never used for any other purpose. If for any reason the starter battery is depleted, the driver can start the car, using the vehicle power supply battery as the source of starting power. The Phaeton on-board power supply control unit (J519 module) will do this automatically if a voltage level of less than 11 volts is detected on either battery.
The driver can also manually invoke the "emergency start" mode. This is done by turning the key fully to the clockwise (start) position, then fully anticlockwise to the accessory position, then to start again.
During cold weather operations (