1. HV Battery Assembly

2. HV Battery Assembly Power Supply
The HV battery supplies power to MG1 / MG2
The auxiliary battery supplies power to HV ECU and Engine ECU (all ECU)
When both are functioning properly, the vehicle will start
2 types of battery.
- HV battery (DC201.6V)
- Auxiliary battery (DC12V)
HV Battery
(DC 201.6V)
Auxiliary Battery
(DC 12V)

3. Service Plug Connector
HV Battery Assembly
Components
Module
Current Sensor
Battery ECU
SMR3
SMR2
SMR1
Service Plug Connector
Resister

4. HV Battery Assembly Battery Module
Nickel metal hydride (Ni-MH) battery (1.2V x 6 cells) x 28 modules = 168 cells = DC V
28 Module
(1.2V x 6 cells) x 28 modules = 168 cells x 1.2V = DC V
Module
(1.2V x 6 cells)

5. HV Battery Assembly Battery ECU
Maintains control of HV battery SOC (State of charge)
Ensures battery capability
Battery ECU
CAN
SOC Control
Cooling Fan Control
Electrical Leakage Detection for High-voltage System
Diagnosis Function for HV Battery
HV Battery Condition Detection
Battery Cooling Fan Relay
HV ECU
Engine ECU
A/C ECU
Battery Cooling Fan Controller
Voltage x 14
Temp. x 4 +
Temp. Sensors (Thermistor)
Service Plug
Battery Cooling Fan Motor -
Current Sensor
HV Battery

6. HV Battery Assembly Battery ECU
Controls SOC to match THS characteristics
The SOC is maintained at approx, 60%. A margin is given for further recharging via regenerative braking
Sends requests to HV ECU to obtain desired SOC
SOC (State Of Charge)

7. HV Battery Assembly SOC Control
When the SOC is dropped, battery ECU sends the “Charge Request” signal to HV ECU
Battery ECU
Charge Request
Power Request
HV ECU
Engine ECU
SOC
Control
Voltage (SOC)
Charging
Charge
MG1
Drive
HV Battery
Engine

8. HV Battery Assembly SMR (System Main Relay)
Turns ON / OFF the high-voltage circuit
SMR3
SMR1
SMR turns ON / OFF the high-voltage circuit.
SMR2

9. HV Battery Assembly STEP 1: SMR 1 / SMR 3  ON STEP 2: SMR 2  ON
When the power is ON (READY ON)
STEP 1: SMR 1 / SMR 3  ON
STEP 2: SMR 2  ON
STEP 3: SMR 1  OFF

10. HV Battery Assembly STEP 1: SMR 1 / SMR 3  ON STEP 2: SMR 2  ON
When the power is ON (READY ON)
STEP 1: SMR 1 / SMR 3  ON
STEP 2: SMR 2  ON
STEP 3: SMR 1  OFF

11. HV Battery Assembly STEP 1: SMR 1 / SMR 3  ON STEP 2: SMR 2  ON
When the power is ON (READY ON)
STEP 1: SMR 1 / SMR 3  ON
STEP 2: SMR 2  ON
STEP 3: SMR 1  OFF

12. HV Battery Assembly STEP 1: SMR 1 / SMR 3  ON STEP 2: SMR 2  ON
When the power is ON (READY ON)
STEP 1: SMR 1 / SMR 3  ON
STEP 2: SMR 2  ON
STEP 3: SMR 1  OFF

13. HV Battery Assembly STEP 1: SMR 2  OFF STEP 2: SMR 3  OFF SMR
When the power is OFF
STEP 1: SMR 2  OFF
STEP 2: SMR 3  OFF

14. HV Battery Assembly STEP 1: SMR 2  OFF STEP 2: SMR 3  OFF SMR
When the power is OFF
STEP 1: SMR 2  OFF
STEP 2: SMR 3  OFF

15. HV Battery Assembly STEP 1: SMR 2  OFF STEP 2: SMR 3  OFF SMR
When the power is OFF
STEP 1: SMR 2  OFF
STEP 2: SMR 3  OFF

16. HV Battery Assembly SMR System diagram Inverter SMR2 HV Battery SMR1
Service Plug
Resister
Voltage Sensor
HV Battery
Current Sensor
SMR1
SMR3
Interlock Switch (Inverter Cover)
Battery ECU
HV ECU
Interlock Switch (Service Plug)
Power Switch
Power Source Control ECU
Airbag Sensor Assembly
Circuit Breaker Sensor

17. (Service plug grip disconnection, Inverter cover open)
HV Battery Assembly
SMR
Shutdown control
READY OFF
At Collision
When one of the following conditions occurs, HV ECU shutdowns the SMR.
- Ready OFF operation is done by the driver.
- The vehicle collided.
- Inter lock switch is OFF. (service plug grip disconnection, inverter cover open)
Interlock Switch OFF
(Service plug grip disconnection, Inverter cover open)

18. HV Battery Assembly Service Plug
Shut off the high voltage circuit manually
Service Plug
Service plug shuts off the high voltage circuit manually.

19. HV Battery Assembly Service Plug
Power is shut off at HV battery midpoint to avoid high voltage electricity flowing into the circuit

20. HV Battery Assembly Service Plug
It contains a interlock switch and fuse
Service Plug
Service Plug Grip
Fuse
Interlock switch is used for the SMR shutdown control.
Cover
Interlock Switch

21. Caution: Wear insulated gloves
HV Battery Assembly
Service Plug
Caution: Wear insulated gloves
[Removal]
[Installation]
[Removal]
1. Lift-up the lever of service plug.
2. Turn the lever.
3. Disconnect the service plug.
[Installation]
1. Connect the service plug
2. Turn the lever
3. Push the lever downward until the click is heard
Caution: Wear insulated gloves when connecting / disconnecting the service plug to prevent against electrical shock.

22. HV Battery Assembly Cooling System
Battery ECU executes a command to switch cooling fan ON when battery temp. rises
Cooling Fan
Air Inlet
Cooling Fan
Controller
Battery Module
: Temp. Sensor

23. Cooling Fan Controller
HV Battery Assembly
Cooling System
Cooling fan motor is stepless controlled
Cooling Fan Controller
Temp. Sensors (HV Battery)
(V) 13
Cooling Fan Motor
Duty Signal
Cooling Fan
Controller
Output Voltage
Battery ECU M 4 30 95
(%)
A/C ECU
Input Duty Ratio
(from Battery ECU)

24. HV Battery Assembly Auxiliary Battery
Auxiliary battery supplies power to headlights, audio, and all ECUs
Auxiliary Battery
Auxiliary battery (12V) supplies power to headlights, audio, and all ECUs.
It is located at the luggage compartment.

25. Never use an ordinary battery
HV Battery Assembly
Auxiliary Battery
Sealed-type battery is used
Notice:
Refrain from quick charging Because the battery fluid cannot be replenished
Never use an ordinary battery
Sealed-type battery is used.
Notice:
Refrain from quick charging. Because the battery fluid cannot be replenished.
If the auxiliary battery needs to be replaced, replace it only with a 12V battery specially designed for the use of the PRIUS.

26. HV Battery Assembly Auxiliary Battery Jump Start Terminal
”+” terminal of auxiliary battery for jump start is used
Jump Start Terminal
”+” terminal of auxiliary battery for jump start is used at the relay block.