Cobasys — Hazardous Materials Safety Interpretation

Page 1Washington, D.C. 20590 400 Seventh Street, S.W. Pipeline and Administration Hazardous Materials Safer JUL 27 2007 Mr. Anthony J. Serventi Senior Counsel Ref. No.: 07-0106 3740 Lapeer Road South Cobasys Orion, MI 48359 Dear Mr. Serventi: This is in response to your letter dated May 23, 2007 requesting clarification of the azardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to desig be testing of lithium-ion cells and batteries. The specific requirements vou address a contained in section 38.3 of the United Nations Manual of Tests and Criteria and are implemented through the provisions of § 173.185 of the HMR. volt A123 cylindrical lithium-ion cells utilizing approximately 518 grams of aggregate In your letter you describe a hybrid electric vehicle battery system consisting of 192 - 3.3 equivalent lithium content. The battery system is equipped with a system that monitor: cell voltage and temperature and incorporates a service disconnect feature. Each cell passed the design-type tests in section 38.3 of the UN Manual of Tests and Criteria and that since the individual cells passed the applicable tests and incorporate additional safet the cells in this assembly are electrically connected by a circuit board. It is your opinion systems, the cell assembly constitutes a "battery assembly" as described in 38.3.3 of the UN Manual of Tests and Criteria and thus the assembly is not required to be tested in accordance with the design-type tests outlined in section 38.3. We do not agree. The system you described meets the definition of a battery or a battery electrically connected together by permanent means, including case, terminals and ack, defined in section 38.3 of the UN Manual of Tests and Criteria as one or more cell: subject to the tests in the UN Manual of Tests and Criteria, even if the cells that make u narkings. Except for single cell batteries, each new lithium cell and battery design-type i the battery have been tested. The fact that the cells are electrically connected by a circuit board that can be disconnected does not mean this assembly of cells constitutes a battery assembly. 173.185 (e) 070106#

Page 2If you believe your hybrid electric vehicle battery system provides and equivalent level of safety to the HMR requirements without additional testing, you may wish to apply for a special permit through the Office of Hazardous Materials Special Permits and Approvals at 202-366-4535. I hope this information is helpful. Sincerely, Chief, Standards Development Office of Hazardous Materials Standards#

Page 3: D COBASYS Anthony J. Serventi Senior Counsel 07-0106 3740 Lapeer Road South Orion, Michigan 48359 Fax: Phone: 248.620.5751 www.cobasys.com 248.620.5753 tserventi@cobasys.com May 23. 2007 US Department of Transportation Edward Mazzullo. Director Pipeline and Hazardous Materials Safety Administration Office of Hazardous Materials Safety SE East Building. 2°° Floor 1200 New Jersey Avenue Washington. DC 20590 Rc: Letter of Interpretation for 49 CFR $173.185(e) Dear Mr. Mazzullo: $173.185(e) ("Section 185(e)") and Section 38.3 of the UN Manual of Tests and Criteria ("UN This correspondence is a formal request for a Letter of Interpretation regarding 49 CFR Manual"'). as it relates to Section 185(e). Cobasys LI.C (Cobasys") is a developer and integrator of batteries. battery packs and battery systems for transportation and stationary applications. Cobasys is currently developing a hybrid electric vehicle (HEV) battery system. which development to further improve the fuel economy of HEVs. Cobasys intends to deliver incorporates lithium battery cells. The next generation of HEV battery systems are under prototypes of the HEV battery system to a customer. a US based automotive OEM. in early July 2007. Initially. Cobasys intends to use ground transportation to deliver the HEV battery systems lithium cells or hatteries to be transported as items of Class 9. As subsection 5 has been Section 185(c) provides the requirements of subsections 1-7. which must be met for have passed all the tests required under Section 38.3 of the UN Manual. Further, as incorporated Reserved. it is not addressed. With respect to the Cobasys HEV battery system. the lithium cells into the Cobasys HEV battery system. the lithium cells and Cobasys HEV battery system meet the all the requirements of Section 185(c). The focus of our inquiry is the necessity to test the subject Cobasys HEV battery system according to subsection 6 of Section 185(e). in view of the fact that the lithium cells. which make up the system, meet the requirements subsection 6 of Section 185(c). A description of the Cobasys HIV battery system is provided in Exhibit A. Section 38.3 of the UN Manual. "cell" is defined as "a single encased electrochemical unit (one The UN Manual provides a series of 8 tests for cells and batteries. For the purposes of positive and one negative electrode) which exhibits a voltage differential across two terminals#

Page 4Page 2 SP 310 - Approvel Process and "battery" is defined as "one or more cells which are electrically connected together by permanent means. including case. terminals, and markings." Referring to Exhibits B and C. the cells of the Cobasys HEV battery system are electrically connected utilizing a circuit board. connected. because the circuit board may be disengaged from the lithium cell assembly. Although the cells are electrically connected by a circuit. the cells are not permanently Section 38.3.3 of the UN Manual provides as follows: *When batteries that have passed all applicable tests are electrically connected to when fully charged, is more than 500g. that assembly does not need to be tested if form a battery assembly in which the aggregate lithium content of all anodes, it is equipped with a system capable of monitoring the battery assembly and and any overheat or overcharge of the battery assembly. preventing short circuits, or over discharge between the batteries of the assembly UN Manual. Cobasys has drawn the conclusion that the Cobasys HEV battery system is a As indicated earlier, the lithium cells have passed all the tests required under Section 38.3 of the assembly of cells. The aggregate lithium content of the Cobasys HEV battery system is more content. Therefore, the Cobasys HEV battery system does not require testing under Section 38.3 than 500g. The Cobasys HEV battery system utilizes approximately 518 g of equivalent lithium assembly and preventing short circuits, or over discharge between the batteries of the assembly of the UN Manual, because it is equipped with a system capable of monitoring the battery and any overheat or overcharge of the battery assembly," as described in Exhibit A. For voltage and temperature, and controls contactors which are. essentially, high-voltage switches. example. the Cobasys HEV battery system includes an electronic controller which monitors cell close and become conductive. Since the Cobasys HEV battery system will be shipped in an Further, the contactors require external 12 V power to be applied to the controller in order to through the cell stack. Additionally. the Cobasys HEV battery system incorporates a service unpowered state, the contactors will be in an open state. also breaking the conductive path disconnect system as illustrated in Exhibit D. The service disconnect system incorporates a service disconnect which is removed from the Cobasys HEV battery system during transport. The service disconnect is an integral part of the high-voltage current path. When the service disconnect is removed from the pack. the conductive path is broken and no current may flow through the cell stack of the Cobasys HEV battery system. Exhibits B and C, illustrations of the Cobasys lithium HEV system; and 3) Exhibit D, an Attached are 1) Exhibit A, a written description of the Cobasys lithium HEV system: 2) illustration of the service disconnect system.#

Page 5Page 3 Thank you for your time and help. Please contact me with any questions or concerns. Sincerely. Anthony J. Serventi#

Page 6Exhibit - A Cobasys Lithium Hybrid Electric Vehicle Battery system Description The Li-ion battery system contains one-hundred-ninety-two (192) 3.3 Volt cylindrical cells which are connected in a series-parallel arrangement (2-parallel, disconnect is implemented to divide the battery system into two separate 96-series). The nominal system voltage is 370VDC (9.0 Ah per cell). A service 185VDC strings. A centralized Battery Pack Control Module (BPCM) is included for contactor control and provides energy storage system status information necessary for optimized energy management. The BPCM interfaces with all cell sensors and controllers that offer voltage and temperature monitoring as well as for a complete system are included. cell balancing for optimized cell usage. The other electronic components needed LAN allows full reporting to the vehicle control system including monitored BPCM communication to the vehicle via variables, management system utilizes air-cooling. diagnostics and battery SOC/SOH/power-available. 1. Cell Assemblies Bus Bars / Interconnects Lithium Ion Cells Temperature Sensors Cell Restraint Structures Sense Leads for Battery Voltages and Temperatures 2. Battery Pack Control Module. The following sets of functions are implemented: A Battery Monitoring Functions Measure HV Battery Voltage, Temperature, and Current. Monitor each Cell. Balance Cells (if necessary). Diagnose each input. Monitor Isolation of cells with Contactor Open, once per key cycle. B. HV Safety, Disconnect, and Thermal Functions Communicate on high speed LAN#

Page 7Control Pre-Charge and Main Contractors. Source and Sense High Voltage Interlock Circuit (Simple Open / Control and Diagnose of a Variable Speed Cooling Fan. Closed circuit. C. Battery State Estimator Functions Cobasys Battery State Estimator (BSE) Algorithms to Calculate: State of Charge, State of Health, Voltage Limits. Power Limits, and ). Manage Charging Nake-Up when Charger provides 12V power and "Ready signal Determine need for charging Open contactors on fault Control charging with PWM signal to charger needed) Control cooling system while charging lower battery temperature (if E. Precondition Battery Temperature Manage battery heater to raise battery temperature during cold weather soaks to provide energy and power upon next use Only active while connected to chargel and functions: 3. High Voltage Battery Disconnect Unit includes the following subcomponents Main Serviceable Fuse. 2 Main Contactors. 2 Charger Contactors Pre-Charge Resistor (~10 Ohm). Pre-Charge Contactor. Current Sensor Voltage Sense Leads. HV Bus Main Positive/Negative Lugged Ring Terminal Connections for Propulsion Secondary Positive/Negative Lugged Ring Terminal Connections for 15 A Charger 4. Service Disconnect With Fuse rated for increased EV type driving duty cycle High Voltage Interlock (Shorting Plug Style) 5. Thermal Management System. External Fan assumed. Battery Heater.#

Page 8Shipping conditions of battery system 1. Transported ground only Class 9 (Class 9 UN 3090 Packing Group II) Hazardous Material following requirements of 49 CFR 173.185(c)(1-7). 2. Service disconnect handle removed. All Battery Disconnect Unit contactors open. See Exhibit D. 4. Protective cover on/over high voltage terminals.#

Page 9Board lAl Auxiliary EXHIBIT - B CELL ASSEMBLY (2) Plate Ass. (TIPA) (3) Terminal Interconnect 230 PHEV BATTERY PACK ASSEMBLY Unit (BDU) (2) Battery Disconnect#

Page 10Lion (32157) PHEY CELL ASSEMBL EXHIBIT - C#

Page 11EXHIBIT - D service Disconnect " PHEV Battery Disconnect Unit Power Distribution U6 U5 U4 10 ohm 40 w Pre Charge Resistor To Heater + Main Power Assembly Resistor Pre Charge Main Power + Charger - Charge! Charger To Vehicle To#