Plug-In Charging System Components

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

1. The off-vehicle charging equipment:
   • Drive motor battery charger cable, often referred to as the travel cord set
   • Optional, permanent level 2 220 - 240 V AC charge station
   • Public/commercial level 3 DC 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 K57B Battery Charger Control Module 2.
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 dual-mode drive motor battery charger cable provided with the vehicle features a standard household alternating current (AC) electrical plug on one end and a plug designed to interface with the vehicle's hybrid/EV battery charger receptacle on the other end. The dual-mode 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. It is often referred to as the travel cord set. Two types of household electrical plugs are included. One will interface with a standard 120V receptacle for level 1 charging. The other will interface with a 220 - 240V receptacle for level 2 charging. Level 1 charging is limited to 8 amps unless the vehicle is located at its registered 'home' location. When connected at 'home', the level 1 charge limit can be raised to 12 amps.

An optional level 2 home charge station is available for customers who want to reduce the amount of time needed to recharge. The optional charge station connects only to a 220 - 240V power supply and typically is 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. Level 1 and level 2 AC charge current is converted by the on-vehicle T18 Battery Charger Module and the K57B Battery Charger Control Module 2 to direct current (DC) to charge the hybrid/EV battery pack.

A level 3 off-vehicle direct current (DC) fast charge drive motor battery charger allows charging using DC current supplied directly to the drive motor battery, bypassing the on-vehicle battery charging. Level 3 chargers are typically only found in a commercial/public location as they are cost-prohibitive for individual vehicle owners. Level 3 charging includes a locking device on the receptacle to prevent removal while large amounts of current is flowing.

The Drive Motor Battery Charger Cable Indicators and the Vehicle Indicators 

The drive motor battery charger cable has indicators which display its status.

The off-vehicle battery charging equipment is supervised and controlled by the K16 battery energy control module, also known as the hybrid/EV powertrain control module. The hybrid/EV powertrain control module is the system controller, and all diagnostic trouble codes will set in that module even though some of the diagnostics are actually run within the T18 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 and audio tones. The vehicle charge status indicator, located on the top of the instrument panel, will be short flashing green when the hybrid/EV battery is at lower state of charge. The flash rate decreases as the battery charges to higher state of charge. It will be pulsing blue if the charging is delayed and will begin later. It will be solid green when charging is complete. A pulsing red indicator or a solid blue indicator followed by a blank indicator means the vehicle is not able to accept a charge. If there is no initial indicator, the drive motor battery charger cable is not working properly or not connected.

Vehicle Receptacle 

The vehicle receptacle or X98 Battery Charger Coupler, is located behind the charging port door. The receptacle is accessed by opening the receptacle door. The receptacle is equipped with a DC fast charge locking mechanism preventing removal while level 3 charging current is present. A manual release cable is provided for situations in which the coupler lock does not disengage automatically such as loss of 12V vehicle power. Only operate the manual release cable when necessary and never when actively DC fast charging. The manual release cable cannot be pushed back to the 'home' position. Each DC fast charge coupler un-mate will result in one attempt of the lock actuator to return to the home position. Five DC fast charge coupler mates/un-mates without successful cable retraction to the home position will result in a DTC. To facilitate higher charge rates, some vehicle receptacles are liquid cooled.

Battery Charger 1 and 2 

The T18 Battery Charger is the primary high voltage charger.

The T18 Battery Charger, also known as the drive motor power distribution control module, contains several micro-processors, two separate high voltage (HV) chargers, serviceable high voltage fuses and a 14V Power Module. One of the internal high voltage chargers is used while charging with a 120V AC charge source, and both are used with a 230/240V AC charge source. The T18 Battery Charger is mounted in the front of the vehicle. DEX-COOL® coolant is used to ensure that the charger does not exceed its maximum designed operating temperature. Refer to Powertrain Component Views , and Hybrid/EV Cooling System Description and Operation .

The 14V Power Module portion of the T18 Battery Charger converts high voltage (400V) direct current (DC) from the hybrid/EV battery to low voltage (12V) DC for accessory electrical operation and to charge the 12V battery. The 14V Power Module is capable of supplying up to 275 Amps of 12V DC.

The K57B Battery Charger Control Module 2 is the secondary high voltage charger. Located in the front of the vehicle behind the coolant radiator, the K57B Battery Charger Control Module 2 supplements the T18 Battery Charger when available level 2 electrical current exceeds the capabilities of the T18 Battery Charger alone. During fault conditions, if either battery charger is unavailable, the functional charger will assume all charging functions. For service and diagnostics purpose a scan tool device control is available that will temporarily force only the K57B Battery Charger Control Module 2 to function within the lower electrical current range normally associated with T18 Battery Charger solo operation. DEX-COOL® coolant is used to ensure that the charger does not exceed its maximum designed operating temperature. Refer to Powertrain Component Views , and Hybrid/EV Cooling System Description and Operation .

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.

With Vehicle Off, the body control module will wake up every 11 hours to monitor the 12 V battery state of charge (SOC). If the 12V battery SOC is low, the K16 battery energy control module is requested to close the hybrid/EV battery high voltage contactors and charge the 12 V battery via the 14V Power Module portion of the T18 Battery Charger.

Under normal circumstances, with a 12V 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 12V battery until the high voltage hybrid/EV battery pack state of charge drops to about 12% state of charge.

Battery Too Cold Support Mode 

If the vehicle has been left unplugged in extreme cold conditions for too long, the hybrid/EV battery pack may become too cold to allow the high voltage contactors to close. If the vehicle is plugged in under this condition the T18 Battery Charger will convert only level 2 AC current into enough high voltage DC current to operate the E54V Hybrid/EV Coolant Heater even though the high voltage contactor relays are open. Once the hybrid/EV battery pack is sufficiently warm, the high voltage contractor relays will close and vehicle propulsion and charging will be restored.