Stationary Charging Function - GF54.10-P-0010RFH

Model 205.047/147/247, 253.954 with engine 274.920 

Model 253.354 with engine 274.920 

Function requirements for stationary charging function 

• Selector lever position "P" or "N"

General information on stationary charging 

When the charging cable is connected to the charger feed socket (X58/23) and to the private (stationary service line) or a public power network (charging station), the high-voltage battery (A100g1) is externally charged. The following components, which communicate with each other over the CAN network, are the primary components involved in this external charging process:

• Powertrain control unit (N127)
• Charger (N83/5)
• Battery management system control unit (N82/2)
• High-voltage battery (A100g1)
• ME-SFI control unit (N3/10)
• Charger feed-in socket
• Instrument cluster (A1)
• Electronic Stability Program control unit (N30/4)
• Fully integrated transmission control unit (Y3/8n4)

Stationary charging, function sequence 

The heat produced during the charging process is dissipated via low-temperature circuit 2. Further information is available in the document

High-voltage system cooling, function. 

The driver has the option of defining the departure time and the maximum charging current via the instrument cluster. There are two charging options available for this:

• Immediate charging 
• Charging with departure time 

Immediate charging 

When immediate charging  is selected in the instrument cluster, the high-voltage battery is immediately charged with the available energy from the power network.

Charging with departure time 

Similarly, when charging with departure time  is selected in the instrument cluster, the high-voltage battery is charged with the available energy from the power network. The departure time setting is relevant for the use of the stationary climate control and, assuming an optimized charging process, represents the completion of the charging sequence.

Charging process 

The entire charging process is monitored. The charger and the energy source (e.g. charging station) communicate over a data line in the charging cable (Control Pilot (CP)). When charging at a mains outlet, the charging current must be limited if necessary to ensure that the local power network is not overloaded. The maximum permissible charging current can therefore be set via the control box on the charging cable or alternatively via the instrument cluster in the vehicle. The most recently selected value is retained in the instrument cluster until it is changed again.

If necessary, a part of the available energy is used for recharging the on-board electrical system battery and/or for the vehicle's climate control (pre-entry climate control).

Stationary charging is subdivided into the following subfunctions:

• Locking the charger feed socket 
• Emergency release cable of the manual emergency release 
• Start-off protection 
• Charging 

Locking the charger feed socket 

When the charging cable has been correctly plugged into the charger feed socket, indicated by the white locking/unlocking LED ("open padlock" symbol) on the charger feed socket, it is locked by the actuator motor of the electric lock (the locking/unlocking LED goes out and the charge indicator LED lights up), to prevent the charging cable from being disconnected from the vehicle inadvertently.

The Proximity Pilot (PP) contact is used to detect whether the vehicle or charger column plug connection is plugged in. The Proximity Pilot (PP) contact also reads out the coding for the maximum current load capacity for the charging cable through a resistor installed in the charger cable plug connector.

Emergency release cable of the manual emergency release 

Courtesy of MERCEDES-BENZ USA

Emergency release of the charging cable 

The charging cable connector is protected from unauthorized removal during the charging process by being locked into the charger feed-in socket through the actuator motor of the electric lock.

If the charging cable cannot be unplugged after a charging process from the vehicle socket (in event of a fault), the actuator motor for the electric lock can be unlocked with an emergency release cable. The emergency release cable is located on the right-hand edge of the trunk. To gain access to the emergency release cable, the covering has to be removed beforehand. When the emergency release cable of the manual release mechanism is pulled, the disk of the manual emergency release is rotated and the charging cable plug is unlocked.

Courtesy of MERCEDES-BENZ USA

Shown on model 253.954 

Start-off protection 

To prevent the vehicle being driven away during a charging process or when the charging cable is plugged in, when a charging cable plug is detected by the Proximity Pilot (PP) contact as being as plugged-in to the charger feed-in socket, the start-off protection in the transmission is activated and a corresponding warning message is shown on the instrument cluster (A1).

The start-off protection is realized here in two variants dependent on the vehicle speed:

• Plugged-in charging cable connector detected while driving (v > 5 km/h) 
• Plugged-in charging cable connector detected at standstill (v < 5 km/h) 

Plugged-in charging cable connector detected while driving (v > 5 km/h) 

If, while driving (v > 5 km/h) a supposed plugged-in charging cable connector (Proximity = ON) or in the event of a defective charger the substitute value (Proximity = SNA) is detected, then the start-off protection is not activated until drive range "P" is engaged.

Plugged-in charging cable connector detected at standstill (v < 5 km/h) 

If a plugged-in charging cable connector (Proximity = ON) is detected in the drive range "P" or at v < 5 km/h, the start-off protection is immediately activated. In the event of a defective charger, the substitute value (Proximity = SNA) is then formed. In this instance, the drive-away protection is not activated until gear range "P" is engaged.

Charging 

If the powertrain control unit has received the signals for selector lever position "P" and "charging cable plugged in" status, it enables charging. The charging process commences. Charging occurs on a 230 V AC power network with one phase or on a 400 V three-phase network with two phases, depending on availability. The charge indicator LED at the charger feed socket flashes green to show that the charging process has been initiated. When the charging process is complete, the charge indicator LED shines with a steady green light.

If faults occur before, during or after charging, the charge indicator LED at the charger feed-in socket flashes red.

The other states of the indicator LED and the locking/unlocking LED and their causes are listed in the table below.

When required, the on-board electrical system battery (G1) is charged through the integrated DC/DC converter (model 205.047/147/247) or the DC/DC converter control unit (N83/1) (model 253.954/354).

Model 205.047/147/247

DC/DC converter

A DC/DC converter is integrated into the power electronics control unit, that converts the high voltage direct voltage (primary voltage) into 12 V direct voltage (secondary voltage) and the transfers this between the high-voltage on-board electrical system and the 12 V on-board electrical system.

Model 253.354/954

DC/DC converter control unit

The DC/DC converter control unit is installed as an independent component part in the vehicle. The DC/DC converter control unit converts a high voltage direct voltage (primary voltage) into a 12 V direct voltage (secondary voltage) and transfers this between the high-voltage on-board electrical system and the 12 V on-board electrical system.