Transcript Portable Rechargeable Battery Association Presentation

UN Informal Working Group Meeting
on Lithium Battery Tests
Ideas to Address Problems Testing
Large and Small Cells and Batteries
November 11-13, 2008
Washington, DC
George A. Kerchner
Executive Director
Portable Rechargeable Battery Association
Problems with Tests
 Not updated in 8 years
 Do not take into account changes in
technology, applications and experience
 Inconsistent interpretations of UN testing
requirements and terminology
 More harmonization needed with terminology found
in international standards (e.g., IEC)
 Impractical to test large batteries (e.g., for
HEV) to the same criteria as small batteries
(e.g., for PC)
New Design Type – UN Manual
Section 38.3.2.1
 Lithium cells or batteries which differ from a
tested type by:
 (a) A change of more than 0.1 g or 20% by
mass, whichever is greater, to the cathode, to
the anode, or to the electrolyte; or
 (b) A change that would materially affect the
test results,
shall be considered a new type and shall
be subjected to the required tests.
Changes to 38.3.2.1 for
Rechargeable Cells and Batteries
 Cells or batteries which differ from a tested type
by:
 (a) for primary cells and batteries, a change of
more than 0.1 g or 20% by mass, whichever is
greater, to the cathode, to the anode, or to the
electrolyte;
 (b) for rechargeable cells and batteries, a change in
Watt-hours of more than 20% or an increase in
voltage of more than 20%; or
 (c) a change that would materially affect the test
results,
shall be considered a new type and shall be
subjected to the required tests.
Small and Irregular Shaped Cells
and Batteries
 Vibration and shock tests require three mutually
perpendicular mounting positions of the cell or
battery
 Difficult to define 3 distinct planes for very small
and irregular shaped cells and batteries
 Variation needed in sections 38.3.4.3.2 (vibration
test procedure) and 38.3.4.4.2 (shock test
procedure)
 Variations also may be needed in other testing
requirements
Mass Loss in Thermal Test –
Section 38.3.4.2
 Mass loss may occur due to material used
in the battery
 Mass loss should only be attributable to cell
 Amend mass loss definition –

“Mass loss means a loss of mass from cells
that exceeds …. “
Impact Test on Component Cells
From Batteries
 Component cells testing noted only in Test 6
(Impact test) – Section 38.3.3(c)(ii) and (c)(iv)
 What is intent?
 UN Model Regulations, IMDG Code and ICAO
TI require that cells or batteries be subject to UN
tests
 Add a clarifying “Note” under component cell
definition similar to Note under current battery
definition
Testing Single Cell Batteries
 UN Manual of Tests and Criteria “Cell”
definition, Section 38.3.2.2
 Cell means a single encased electrochemical unit (one
positive and one negative electrode) which exhibits a
voltage differential across its two terminals. Under
these Regulations, to the extent the encased
electrochemical unit meets the definition of "cell"
herein, it is a "cell", not a "battery", regardless of
whether the unit is termed a "battery" or a "single cell
battery" outside of these Regulations.
Testing Single Cell Batteries
 If cell is tested, is it really necessary to re-test
single cell battery for classification purposes?
Large Lithium Batteries
 More realistic definition needed for large
and small batteries
 Impractical to test large batteries and
assemblies (e.g., HEV) to same criteria as
small batteries (e.g., PC)
 UN vibration and shock tests problematic for
large batteries
 Modifications to shock and vibration tests
needed to account for large batteries and
assemblies
Large Lithium Battery Definition
 Current: > 6200 Wh for Lithium ion and
> 500 g for Lithium metal
 Recommended: > 600 Wh for Lithium ion
and > 80 g for Lithium metal
 Takes into account current technologies,
applications and experience of automobile
and battery manufacturers
Large Lithium Battery Testing
 Cost is a major factor when testing large
rechargeable batteries
 24 rechargeable batteries currently required for
testing

Reduced to 16 in 2011 as a result of decision on PRBA
proposal at July UN meeting
 8 large rechargeable batteries is sufficient for
classification purposes
 Same number (8) currently required for primary
batteries
“Large” Battery Assembly Testing
 UN-tested lithium batteries electrically
connected to form a battery assembly with
more than 500 g or 6200 Wh
 Assembly does not require testing if 
Equipped with a system capable of monitoring
the battery assembly and preventing short
circuits, or over discharge between the
batteries in the assembly and any overheat or
overcharge of the battery assembly
“Small” Battery Assembly Testing
(< 500 g Li Metal or 6200 Wh)
 Test one (1) battery assembly in a fully
charged state under Tests 3, 4 and 5, in
addition, Test 7 in the case of rechargeable
battery assemblies
 Rechargeable battery assemblies must be
cycled at least 25 times
 Assembly must be comprised of cells and
batteries that have passed required UN tests
Vibration Test – T3
 Current vibration test parameters based on
transportation of small cells and batteries
 Parameters do not realistically apply to
larger batteries
 Example: HEV battery systems are
assemblies of electronic controllers,
sensors, air flow ducts, cabling, cell
mounting fixtures, cells, trays, covers and
attachment brackets
Amend Vibration Test
 Amend vibration tests for batteries >
600 Wh or 12 kg

For Large batteries or batteries exceeding 12 kg,
the logarithmic frequency sweep is as follows: from
7 Hz a peak acceleration of 1 gn is maintained until
18 Hz is reached. The amplitude is then maintained
at 0.8 mm (1.6 mm total excursion) and the
frequency increased until a peak acceleration of
2 gn occurs (approximately 50 Hz). A peak
acceleration of 2 gn is then maintained ….
Shock Test – T4
 Shock values do not realistically apply to
larger batteries
 “Small” cells and batteries subject to a halfsine shock of peak acceleration of 150 gn
and pulse duration of 6 milliseconds
 “Large” cells and large batteries subject to
a half-sine shock of peak acceleration of 50
gn and pulse duration of 11 milliseconds
Amend Shock Test
 Testing of HEV-type battery packs at 150
gn is impractical
 Recommend limiting acceleration to 50
gn for batteries > 600 Wh or 12 kg
Overcharge Test – T7
 Batteries (modules) used to construct
battery assemblies frequently designed
without overcharge protection
 Not designed to be or expected to be
charged independently by anyone other
than the manufacturer
 Not possible to conduct Overcharge test on
batteries (modules) because electronic
overcharge protection is designed into
battery assembly
Amend Overcharge Test
 Amend Section 38.3.3(d) by adding
following provision:

“Batteries not equipped with overcharge
protection that are designed for use only in a
battery assembly, which affords such
protection, are not subject to the requirements
of this test.”
Interpretations
 No defined mechanism for official interpretations
 Should there be a UN guidance manual on lithium
battery testing requirements?
 How do interpretations get circulated or
distributed internationally?
 Should there be an annual meeting of “experts”
on lithium batteries similar to UN experts on
explosives?
 Harmonization with terminology in international
standards would provide for more consistency