Description And Operation - Battery Cooling System
DESCRIPTION: The Battery Cooling System is a separate low pressure (5 psi) system used to maintain temperature control of the high voltage battery pack. The system consists of a chiller valve, battery coolant pump, battery coolant heater and split high voltage batteries.
OPERATION:
| 1 - Coolant Temperature Sensor - HV Coolant Heater Input |
| 2 - Electric Coolant Pump |
| 3 - Coolant Temperature Sensor - HV Coolant Heater Output |
| 4 - Coolant Temperature Sensor - Radiator Output |
| 5 - Coolant Temperature Sensor - Radiator Input |
| 6 - Coolant Level Sensor - Low Temp |
| 7 - Electric Coolant Pump |
| 8 - Electric Coolant Pump |
| 9 - 3 Way Valve |
The Battery Pack Control Module (BPCM) maintains the high voltage battery internal temperature at an optimum operating range. The battery coolant pump circulates the coolant through the entire battery cooling system. The battery coolant heater or chiller valve are controlled to either heat or cool the HV battery depending on ambient temperature and battery internal temperature. When the ambient temperature and internal battery temperature are cold the battery coolant heater is used to heat the coolant and bring the HV battery pack to optimal operating temperature. When the battery internal temperature increases to the high threshold the coolant passes through the chiller valve to dissipate heat from the system.
- The battery coolant heater is connected to a HV cable from the BPCM. The battery coolant heater is provided battery power from a relay and a chassis ground. The battery coolant pump is provided battery power and a chassis ground. The BPCM controls the operation of the battery coolant heater and the battery coolant pump using a common LIN bus communication line.
- The chiller valve performs the operation of a radiator for the battery cooling system. The chiller valve is provided battery power and a chassis ground. The PIM controls the operation of the chiller valve, electric coolant heater used in the engine cooling system, and the electric A/C compressor using a common LIN bus communication line. The electric A/C compressor is used to circulate refrigerant throughout the entire A/C system. Refrigerant from the A/C system is circulated to the chiller valve. When battery cooling is needed, the PIM commands the chiller valve to open allowing refrigerant to flow through the chiller valve removing heat from the coolant in the battery cooling system.