Plug-In Charging System Components

The high voltage battery charging system consists of five main components:

1. The off-vehicle charging equipment:
   • Drive motor battery charger cable, often referred to as the travel cord set
   • Optional, permanent 220 - 240 V charge station
2. The hybrid/EV battery charger receptacle, often referred to as the drive motor battery charger receptacle.
3. The T18 battery charger, often referred to as the drive motor battery charger.
4. The T24 battery charger - DC
5. The hybrid/EV battery pack.

A variety of mechanical, visual, and audio indicators/devices are used to communicate with the user of the charging equipment.

Drive Motor Battery Charger Cable/Charge Station 

The drive motor battery charger cable provided with the vehicle features a standard household electrical plug on one end and a plug designed to interface with the vehicles hybrid/EV battery charger receptacle on the other end. The drive motor battery charger cable features a charge current interrupt device with AC power and fault indicators, and it is stored in the vehicle's cargo area. An optional charge station is available for customers who want to reduce the amount of time needed to recharge. The optional charge station, if available, is hard-wired to a 220 - 240 V power supply and must be permanently mounted at the customer's location. The optional charge station features the same plug on the vehicle end as the drive motor battery charger cable.

The Drive Motor Battery Charger Cable Indicators and the Vehicle Indicators 

The drive motor battery charger cable has two indicators, the AC Present Indicator and the Fault Indicator, which display its status.

• Solid green AC Present Indicator means AC voltage is present at the wall plug and there are no faults.
• Flashing green AC Present Indicator and solid red Fault Indicator means the electrical outlet or plug is faulty or overheated.
• Solid red Fault Indicator means the AC outlet does not have a proper ground and charging is not permitted for safety reasons.
• Flashing red Fault Indicator means there is a vehicle fault and the charger cable ground-fault circuit interrupter (GFCI) has tripped.
• Solid green AC Present Indicator and flashing red Fault Indicator means the charger cable has failed self-check.

The off-vehicle battery charging equipment is supervised and controlled by the hybrid/EV powertrain control module 2. The hybrid/EV powertrain control module 2 is the primary controller, and all diagnostic trouble codes will set in that module even though some of the diagnostics are actually run within the battery charger. Charging events can be delayed based on electric rates and departure time. The status of charging events, including delays, is communicated to the user through visual indications, instrument panel mounted charge status indicator, and audio tones. The vehicle charge status indicator, located on the top middle of the instrument panel, will be short flashing green when the vehicle is charging under automatic control. The flash rate increases from one to four as the battery charges. It will be long flashing green if the charging is delayed and will begin later. It will be solid green when charging is complete. A solid yellow indicator means the vehicle is not able to accept a charge. If there is no indicator, the drive motor battery charger cable is not working properly or not connected.

Vehicle Receptacle 

The vehicle receptacle, or hybrid/EV battery charger receptacle, is located behind the charging port door. The receptacle is accessed by depressing and opening the receptacle door.

Battery Charger 

The T18 battery charger is a serviceable assembly that internally contains several micro-processors and two separate high voltage (HV) chargers. One of the high voltage chargers is used while charging with a 120 V charge source, and both are used with a 230/240 V charge source. The T18 battery charger is mounted underhood, beneath the K1 14V Power Module. DEX-COOL® coolant is used to ensure that the charger does not exceed its maximum designed operating temperature. The T18 battery charger, along with the K1 14 V power module and the T6 drive motor generator power inverter module, are cooled by the power electronics cooling loop, which is separate from other cooling systems. Refer to Powertrain Component Views , or Hybrid/EV Cooling System Description and Operation .

The T24 battery charger - DC is a serviceable assembly that internally contains several microprocessors, fuses and one or more high voltage contactor relays. The T24 battery charger - DC is mounted underhood, affixed to the T6 power inverter module. Regardless of vehicle option content, the T24 battery charger - DC contains the fuse and relay for the E54 Battery Heater and fuses for the G1 A/C Compressor and the K10 Heater. In vehicles with quick charge DC charging capability, RPO: CBT, there are two additional high voltage contactors that are housed in the T24 battery charger - DC. These additional high voltage contactors allow the high voltage DC batteries to be connected to the X98 Hybrid/EV Battery Charger Receptacle DC charge terminals.

The hybrid/EV powertrain control module 2 measures internal voltages and currents within the T24 battery charger - DC and charge receptacle and verifies they are within the proper range.

Since the T24 Battery Charger - DC does not actually convert electrical current, no cooling is required.

12 V Battery Maintenance Mode 

Battery Maintenance Mode is an automatic function that prevents deep discharge of the 12 V battery in specific circumstances. It is not dependent on the drive motor battery charger cable being plugged into the hybrid/EV battery charger receptacle. It functions either when the drive motor battery charger cable is plugged in or unplugged. Operation differs depending on whether the power mode is Vehicle Off or Vehicle in Service Mode.

With Vehicle Off, the body control module will wake up the K114B hybrid/EV powertrain control module 2 to monitor the 12 V battery at periodic intervals up to a maximum of 30 days. With Vehicle in Service Mode, the 12 V battery is monitored at periodic intervals up to a maximum of 60 hours. If voltage is low, the 12 V battery is charged by the K1 14 V power module. This function is only intended to prevent a dead 12 V battery and does not provide a full charge. This is more efficient than continuously trickle charging, thus minimizing the usage of high voltage power.

Under normal circumstances, with a 12 V battery that is charged when the vehicle is parked, Battery Maintenance Mode will simply monitor the voltage level, and no charging will be necessary. With Vehicle Off, Battery Maintenance Mode will maintain the 12 V battery for up to 30 days. For longer periods, refer to Owner Manual for instructions.

DC Fast Charging System (if equipped) 

The DC high power fast charge system, RPO: CBT, consists of the stationary off-vehicle DC fast charge station, the DC combo plug, the hybrid/EV battery charger receptacle, the T24 battery charger - DC, and the hybrid/EV battery pack. The high voltage DC current is directly supplied to the hybrid/EV battery pack through the T24 battery charger - DC, bypassing the T18 battery charger, often referred to as the drive motor battery charger. The receptacle has a locking mechanism that locks the DC combo plug while power is being transferred to the hybrid/EV battery pack. The mechanical lock is a safety system that is controlled by the hybrid/EV powertrain control module 2. This locking mechanism will disengage once the charging process is completed or terminated and high voltage DC is reduced to a safe voltage level at the DC combo plug.

The hybrid/EV powertrain control module 2 monitors and verifies the following conditions before the charging process can begin:

• The stationary charge station is capable of providing high voltage DC power to the hybrid/EV battery pack.
• The hybrid/EV battery pack temperature can be maintained within the normal operating range.
• No high voltage electrical safety faults are present.
• The receptacle locking mechanism is operating properly.
• Vehicle immobilization is successful, if equipped.

If any of these conditions fail during the charging process, then the charging process will be terminated.