Nissan Ariya: System

• 2wd
• Awd
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• Li-Ion Battery Temperature Control
• Low Battery Charge Warning

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System Description

SYSTEM DIAGRAM

INPUT/OUTPUT SIGNAL ITEM

Input Signal Item

Output Signal Item

DESCRIPTION

The Li-ion battery controller (LBC) monitors the status of the inside of the Li-ion battery at all times and transmits the information such as the charging status of Li-ion battery and possible power via CAN communication.

The Li-ion battery controller performs control as per the following.

• Monitors the battery state and transfers chargeable/dischargeable power to VCM to prevent an error, such as overvoltage, over discharge or excessive temperature rise in the battery.

• Detects an error (over voltage, over discharge, over current, or excessive temperature rise) immediately at the time of error occurrence and requests VCM to disconnect the system main relay to interrupt the discharge/charge line.

• Maintains the optimum battery state constantly with a cell capacity adjustment function to prevent a reduction in charging/discharging capacity caused by cell capacity variations.

• Detects the connector fit state with the function to detect the fit of the high voltage harness connector and transfers the detected state to VCM so that the Nissan Ariya vehicle does not start with an unsteady state.

• Detects the insulation resistance state with the function to detect the insulation resistance between high and low voltage and transfers the detected state to VCM so that the Nissan Ariya vehicle does not start with an unusual state.

• Estimates a battery charge state and low battery state, based on the data obtained with the battery state detection function, and reflects on the battery capacity meter.

BATTERY PROTECTION

The Li-ion battery has a voltage range capable of charge/discharge. If charged/discharged exceeding the range, excessive low capacity or malfunction may be caused. To prevent this, the Li-ion battery controller detects voltage of each cell and requests the control of charging/discharging energy to VCM so that the cell voltage stays within the voltage range.

HOW TO ADJUST CELL CAPACITY

During cell capacity adjustment, the capacity of each cell is estimated based on the no-load voltage when the system starts, and the capacities are adjusted so that they are all at the target level. The voltage of each cell is detected by each cell controller. The bypass switches are then turned ON to discharge the cells that have excess capacity. In this way, capacity adjustment by each cell controller allows the capacity of all cells to be fully utilized.

INSULATION RESISTANCE LOSS DETECTION FUNCTION

The insulation resistance detection circuit mounted inside the Li-ion battery controller measures the insulation resistance of each high voltage part and sends the measurement results to VCM via CAN communication.

VCM judges abnormal insulation resistance in each high voltage part, based on the received insulation resistance value.

Awd

System Description

SYSTEM DIAGRAM

INPUT/OUTPUT SIGNAL ITEM

Input Signal Item

Output Signal Item

DESCRIPTION

The Li-ion battery controller (LBC) monitors the status of the inside of the Li-ion battery at all times and transmits the information such as the charging status of Li-ion battery and possible power via CAN communication.

The Li-ion battery controller performs control as per the following.

• Monitors the battery state and transfers chargeable/dischargeable power to VCM to prevent an error, such as overvoltage, over discharge or excessive temperature rise in the battery.

• Detects an error (over voltage, over discharge, over current, or excessive temperature rise) immediately at the time of error occurrence and requests VCM to disconnect the system main relay to interrupt the discharge/charge line.

• Maintains the optimum battery state constantly with a cell capacity adjustment function to prevent a reduction in charging/discharging capacity caused by cell capacity variations.

• Detects the connector fit state with the function to detect the fit of the high voltage harness connector and transfers the detected state to VCM so that the Nissan Ariya vehicle does not start with an unsteady state.

• Detects the insulation resistance state with the function to detect the insulation resistance between high and low voltage and transfers the detected state to VCM so that the Nissan Ariya vehicle does not start with an unusual state.

• Estimates a battery charge state and low battery state, based on the data obtained with the battery state detection function, and reflects on the battery capacity meter.

BATTERY PROTECTION

The Li-ion battery has a voltage range capable of charge/discharge. If charged/discharged exceeding the range, excessive low capacity or malfunction may be caused. To prevent this, the Li-ion battery controller detects voltage of each cell and requests the control of charging/discharging energy to VCM so that the cell voltage stays within the voltage range.

HOW TO ADJUST CELL CAPACITY

During cell capacity adjustment, the capacity of each cell is estimated based on the no-load voltage when the system starts, and the capacities are adjusted so that they are all at the target level. The voltage of each cell is detected by each cell controller. The bypass switches are then turned ON to discharge the cells that have excess capacity. In this way, capacity adjustment by each cell controller allows the capacity of all cells to be fully utilized.

INSULATION RESISTANCE LOSS DETECTION FUNCTION

The insulation resistance detection circuit mounted inside the Li-ion battery controller measures the insulation resistance of each high voltage part and sends the measurement results to VCM via CAN communication.

VCM judges abnormal insulation resistance in each high voltage part, based on the received insulation resistance value.

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Harness Layout

Click link to Harness Layout.

Handling Precaution

• For long life of Li-ion battery life, do not use a lot of quick charge.

• Use the method of nighttime normal charge or timer charge.

• Never perform rapid acceleration/deceleration.

• Never place Li-ion battery under direct sunlight or high temperature and humid conditions.

PRECAUTIONS FOR STORAGE OF THE LI-ION BATTERY

• Apply insulating tape to the service plug and high voltage harness connector, and protect the terminals so that nothing contacts them.

• Store in a well-ventilated location that is not exposed to direct sunlight.

  (Storing outdoors or unprotected is prohibited.)

• Never put directly on the floor.

• Lay an electric resistant rubber sheet underneath the battery.

• Never invert the battery.

• Never stack batteries.

• Cover with an electric resistant cover sheet.

• Put a caution display stating "CAUTION HIGH VOLTAGE" on the electric resistant cover sheet.

• Put identification display showing the name of person in charge on the electric resistant cover sheet.

• Never allow water to contact the battery.

• Prevent other objects from falling onto the battery.

Fail-safe

When Li-ion Battery Controller (LBC) detects a malfunction of the Li-ion battery, it enters the control mode to protect Li-ion battery by stopping or limiting the power supply and charging from Li-ion battery.

Since fail-safe mode differs depending on the contents of the detected DTC and vehicle condition, the combination of fail-safe patterns is performed.

• Pattern A: No driving, Charge stop, and EV system warning lamp illuminate

• Pattern B: Driving output power limit, Charge stop, and EV system warning lamp illuminate

• Pattern C: Driving output power limit, Charge limit, and EV system warning lamp illuminate

• Pattern D: EV system warning lamp illuminate

• Pattern E: Quick charge stop and EV system warning lamp illuminate

• Pattern F: Driving output power limit, and EV system warning lamp illuminate

• Pattern G: Charge limit, and EV system warning lamp illuminate

Li-Ion Battery Temperature Control

System Description

SYSTEM COMPONENT

	Reservoir tank (Battery cooling）		Expansion valve (Battery chiller）		Refrigerant temperature sensor (Battery chiller inlet)
	Refrigerant temperature sensor (Battery chiller outlet)		Battery coolant chiller		Electric water pump 2 (Li-ion battery)
	Li-ion battery		Battery coolant heater (Battery PTC)
	To refrigerant cycle

SYSTEM DIAGRAM

OPERATION DESCRIPTION

Battery Coolant Circulation Control

VCM drives electric water pump 2 (Li-ion battery) to regulate the temperature of the battery pack and circulates battery coolant to flow through the Li-ion battery.

Battery Cooling Control

To prevent the heat-up of the battery pack caused by the charge/discharge,  the battery coolant chiller is cooled by the refrigerant cycle and the battery coolant to circulate through Li-ion battery is cooled. Then each module temperature is cooled down.

Battery Heater Control

To prevent the freeze of each battery pack cell in the severe cold, battery coolant to circulate through Li-ion battery by the battery coolant heater (PTC heater) is warmed. Then each module temperature is warmed up.

NOTE:

Battery heater permitting function in driving mode can be set ON/OFF on the touch screen display. Refer to Operation.

Operation

Li-ion battery heater permitting function in driving mode can be set ON/OFF on the touch screen display.

1. Touch [ ] on the Launch Bar.

2. Touch [ ].

3. Touch [EV].

4. Touch [Battery Heater]

Low Battery Charge Warning

System Description

DESIGN/PURPOSE

When the Li-ion battery remaining energy is lowered, warning message is displayed and mark on Li-ion battery capacity level gauge is changed to an orange.

SYNCHRONIZATION WITH MASTER WARNING LAMP

Synchronization is applied.

For master warning lamp, Refer to Design.

SYSTEM DIAGRAM

SIGNAL PATH

• LBC transmits a Li-ion battery remained energy signal to VCM.

• VCM calculates a remaining Li-ion battery power according to a signal received from LBC. When judging low remaining battery power, VCM transmits a low battery charge warning request signal to the combination meter.

DISPLAY CONDITION

When all of the following conditions are satisfied:

• Power switch: ON or READY

• When Li-ion battery SOC is 10% or less.

OFF CONDITION

When Li-ion battery SOC recovers to 11% or more.

TIMING CHART

Component Parts91kwh Li-Ion Battery