# Cobasys — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 07-0106
- **title:** Cobasys — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2007-07-27
- **effective on:** Not available
- **summary:** 07-0106 response to Cobasys concerning 173.185.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-07-0106.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-07-0106.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-07-0106
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2007/070106.pdf
**body:**

<<<PAGE 1>>>

Washington, 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 2>>>

If 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 4>>>

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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 5>>>

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

<<<PAGE 6>>>

Exhibit - 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 7>>>

Control 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 8>>>

Shipping 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 9>>>

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

<<<PAGE 10>>>

Lion
(32157)
PHEY CELL
ASSEMBL
EXHIBIT - C

<<<PAGE 11>>>

EXHIBIT - 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
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