1. Task Force 9: Communication and Messaging
Wayne McKenzie
William Joel Sanchez
Task Force Leaders

2. Background
Project Concern: The automotive application and use of a REESS, such as Lithium-ion battery based system, imposes certain safety risks to the operators and occupants of these vehicles, which are different than that of vehicles using only an internal combustion engine.
Potential Safety Risk: Thermal runaway of the battery pack(s), which in some cases may result in fire or explosion.
Project Scope: This research focuses on the safe management of an automotive REESS, i.e. its BMS and any electronic failures associated with it.

3. Project Goals and Scope
Identify diagnostic and prognostic elements based on a comprehensive HARA of automotive REESS, specifically BMS functionality
Determine information and messaging needs for operators and responders
Write report that informs potential agency regulatory decisions
Scope:
Focus on safe management of an automotive REESS; i.e., its Battery Management System (BMS) and any electronic failures associated with it.

4. Project Objectives
Delineate the hazards and their severity levels pertaining to the functional safety of automotive REESS controls, and identify safety requirements and constraints of BMS functionality
Define system diagnostics, prognostics, and data logging
Identify safety-critical information needs and effective methods to communicate this information to operators
Address safety-related instructions and training needs for operators

5. Safety Concept
Battery Management Controls: Measurement & protection of an automotive REESS, specifically the BMS and its interactions with other vehicle systems.
Fail-Safe Response to Faulted Conditions
Diagnostics/Prognostics
Sensor Validity/Integrity
Cell Voltage
Cell Temperature
Cell Balancing

6. Refinement of Analytical Scope
REESS
HV DC Bus
Battery Pack Box & Seal
Power
Distribution Unit
HV DC Bus
Battery Pack
Current Sensor
Controls/Data
LV DC
Battery Management System (BMS) Controller
HVIL
Controls/Data
CAN Bus
OVERRIDING QUESTION: CAN THE STUFF IN THE BOX HANDLE ANY FAILURE INSIDE OR OUTSIDE THE BOX
OBJECTIVE 1, TASKS 2 & 3
Communication
Protocol
Load Mgmt.
Coolant
Regen Mgmt.
Vehicle
Ground
Charger Mgmt.
Thermal Mgmt.
Crash Detection

7. Automotive REESS System Description System Function Battery Pack
Battery Management System Controller
Power Distribution Unit
System Function
Stores electrical energy received from the charger or the vehicle
Delivers energy to the vehicle systems
Communicates with other vehicle module for proper vehicle functions
Maintains safe vehicle operation

8. Battery Pack Description: Function: Sealed vented box
Battery Pack Box & Seal
Description:
Sealed vented box
Includes the battery modules, voltage sensors, cell voltage balancers, temperature sensors, condensation sensors, and ground fault detection circuitry
Function:
Stores electrical energy
Delivers electrical energy
Communicates cell status and isolation status
Vent
Cell
Voltage
Balancer
Battery
Cells
Interconnects
Battery
Cells
Cell Temp
& Voltage
Sensor
Battery
Cells
Thermal Control
Ground
Fault
Detection
Battery
Cells
Battery
Cells
Condensation
Sensor

9. Battery System Management Controller
Description:
Algorithms including State of Charge (SOC), State of Health (SOH),
Diagnostics and Prognostics
Communication
Data Storage
Safety Controls
Function:
Manages the energy in and out of the battery pack based on the SOC
Acts on safety related requests from other vehicle systems
Maintains the safety of the REESS

10. Power Distribution Unit
Description:
Main contactor
Pre-charge contactor
Relays and fuses
Function:
Controls connection between the battery pack and the High Voltage bus
Ensures that the system power limits are respected

11. REESS External Interfaces
OBJECTIVE 1

12. Scope of External Interfaces
Analysis must consider external vehicle interfaces in terms of their impact on the safe operation of the REESS
REESS must tolerate external failures and maintain a safe state
OBJECTIVE 1

13. Diagnostic Trouble Codes
Breakdown of hybrid power related to sample vehicle used
64% are related to the BMS (Brown & Orange sections)
The Motor Controller (17%) and Charging System (11%) also prominent

14. Communications and Messaging
Identify safety-critical information needs of owners and operators
Describe effective means to communicate this information
Describe barriers to effective communication and opportunities to remove them
OBJECTIVE 3 TASKS 4 & 5

15. HEV/PHEV Status Indications
System Status
Charge State
Low Charge
Discharge Rate/Range
BMW Mini E (BEV)
Chevrolet Volt (PHEV)
Fisker Karma (BEV+)
Nissan Leaf (BEV)
Tesla Roadster (BEV)
(Regen Off)
Toyota Prius (PHEV)
OBJECTIVE 3 & 4

16. HEV/PHEV Malfunction Indications
High Temp.
12V Fault
REESS Fault
Low Power
Hazard
/Other
BMW Mini E (BEV)
Chevrolet Volt (PHEV)
Fisker Karma (BEV+)
Nissan Leaf (BEV)
Tesla Roadster (BEV)
Toyota Prius (PHEV)
OBJECTIVE 3 & 4

17. Questions