Technical data

63
Relay for parallel
wiring battery
Series fuse box
Battery monitor control unit
On-board
network battery
Starter battery
270_231
Two-battery on-board network
Vehicles with
● W 12 and
● V 10 TDI engines
Additional feature for vehicles with
● V 6 engines
The two-battery on-board network consists of a
starter battery, an on-board network battery, a
relay for parallel wiring battery (J581) and a bat-
tery monitor control unit (J367).
The starter battery feeds the starting current cir-
cuit for starting the engine; the on-board network
battery feeds the 12V on-board network.
Starting with a discharged on-board network or
starter battery is possible. Control is effected via
the battery monitor control unit and the relay for
parallel wiring battery.
Both batteries are wired in parallel at tempera-
tures below 0°C in order to satisfy the cold start
requirements of the V10 TDI engine.