Brake energy recuperation (charg-
ing)
When braking the vehicle and when the vehi-
cle moves by inertia or travels downhill in the
deceleration phase, electric power is gener-
ated by the electric engine and stored in the
high-voltage battery. The electric motor then
operates as an alternator and produces a en-
gine braking eect. This process is called brake
energy recuperation.
The engine braking eect can be more or less
intense, depending on the position of the gear
selector ›››page146. If the recuperation
is very intense, the brake light of the vehicle
may also be switched on. As the high-voltage
battery’s state of charge increases, recupera-
tion reduces along with the engine braking
eect. When the high-voltage battery is fully
charged, no energy recuperation takes place
and there is no engine braking eect. When
the vehicle detects that road conditions do not
allow safe contact between the wheels and the
road surface, energy recuperation is automat-
ically reduced, along with the engine braking
eect. The power indicator provides informa-
tion about the availability of recuperation and
the engine braking eect ›››page23.
The vehicle recuperates energy dierently de-
pending on the selected gear position and the
infotainment system settings:
●
Position
D selected and the eco-eicient
driving assistant deactivated: no recuperation
takes place.
●
Position D selected and the eco-eicient
driving assistant activated: automatic recuper-
ation. The recuperation level is automatically
selected based on navigation data and the
traic situation.
●
Position B selected: intense recuperation.
The vehicle also recovers energy when the
brake pedal is depressed.
Eco-eicient driving assistance
The eco-eicient driving assistant helps the
driver to make eicient use of the vehicle's en-
gine braking eect. It selects the recuperation
level based on navigation data and traic situa-
tion.
The assistant can be switched on and o in the
infotainment system’s vehicle settings.
Driving down slopes
On descents, position B should be selected
whenever possible.
Never let the vehicle roll downhill with position
N neutral selected.
WARNING
As the high-voltage battery's state of charge
increases, the engine braking eect drops
and may be completely cancelled out. This
puts much greater demand on the vehicle’s
brakes.
●
When charging the high-voltage battery
in high-altitude locations (e.g. on top of a
mountain pass), never fully charge it. In this
way, when descending the mountain the en-
gine braking eect through recuperation will
be enabled.
●
Slow down before starting a long distance
with a steep descent.
●
During a long distance with a steep de-
scent, reduce the speed with the vehicle
brake.
Troubleshooting
Drive system will disconnect shortly
High-voltage battery state of charge very
low and reduced motive power.
The control lamp comes on while the vehicle is
moving.
The control lamp lights up red.
A message is displayed in the Digital Cockpit.
An audio signal sounds.