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 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 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 hybrid/EV battery pack is assembled with two layers of cell module assemblies, essentially operating like two 400V DC battery packs in one assembly. Under normal operating conditions these two layers operate electrically in parallel with each other and charge at 400V. If conditions allow, the high voltage contactors can be configured such that each layer is wired in series to facilitate level 3 charging at 800V.

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 K16A battery energy control module, also known as the hybrid/EV powertrain control module (primary). The hybrid/EV powertrain control module (primary) 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 at the hybrid/EV battery charger receptacle, 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 solid blue if the charging is delayed and will begin later. It will be solid green when charging is complete. A flashing red 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. A secondary vehicle indicator is operable by the driver and utilizes light bars within the headlamp assembly to convey state of charge status.

Vehicle Receptacle 

The vehicle receptacle or X98 Battery Charger Coupler, is located behind the charging port door. The receptacle is accessed by depressing and opening the receptacle door. The receptacle is equipped with a DC fast charge locking mechanism preventing removal while level 3 charging current is present. To facilitate higher charge rates, some vehicle receptacles are liquid cooled.

Battery 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 rear of the vehicle, above the electric drive transmission. 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.

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 the hybrid/EV powertrain control module (primary) to monitor the 12 V battery at periodic intervals. If voltage is low, the hybrid/EV battery high voltage contactors are closed and the 12 V battery is charged by 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 hybrid/EV battery pack state of charge gets 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.