Informal working group: Large Lithium batteries testing
RECHARGE & SAFT
Washington, Oct. 2nd 2013
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Content:
1.
2.
3.
4.
5.
Examples of large batteries.
Batteries size and compatibility with tests.
Issues relative to 38.3.3 (f) and last § of 38.3.
Proposals for change of 38.3.3.
Proposals for change of définition of « battery
assembly » and « large battery »
6. Proposals for change of T.5 External short circuit
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Examples of “large batteries”
Stationary
ElectroMobility
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Boundaries of an Industrial Battery for E-mobility
4
Boundaries of an Industrial Battery for E-mobility
Inner jacket
Cell
Module
Inner jacket
stack
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Boundaries of an Industrial Battery for E-mobility
Outer
jacket
battery
6
Stationary application: batteries sizes
7
Boundaries of an Industrial Battery for Stationary
Cells
Assembly of cabinets
modules
cabinets
container
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Other types of industrial batteries
 Aviation batteries,
 Tram/ Railways batteries,
 Others,…
9
Content:
1.
2.
3.
4.
5.
Examples of large batteries.
Batteries size and compatibility with tests.
Issues relative to 38.3.3 (f) and last § of 38.3.
Proposals for change of 38.3.3.
Proposals for change of définition of « battery
assembly » and « large battery »
6. Proposals for change of T.5 External short circuit
10
What is the representative size of the
battery for transport?
Most batteries may be transported complete or in sub-parts:
For automotive:
• batteries can be transported complete (full battery pack)
• and/or in sub-parts: modules/stacks (i.e. when requested for
maintenance, transfer between plants,…)
•
For stationary industry:
• Battery can be transported complete in containers (several number of
cabinets possible)
• And/or in cabinets (several number of module possible)
• And/or in modules (maintenance, pre-assembly, etc..)
For other applications: same modularity.
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What can be tested for safety during
transport?
12 kg limit?
6200 Wh limit?
Batt type
Very large
assembly
Automotive
Large Battery
assembly
Battery
assembly
intermediate
Modules,
stacks,
Cells
Battery pack:
Truck and buses
batteries may be
too heavy
Battery pack:
Can be tested
Can be tested
according UN
38.3
Has to be tested
according UN 38.3
Stationary
Container:
Too large
and heavy
for testing
Cabinets
assembly: Too
heavy for testing,
too many
configurations
Cabinet: Can be
tested, however
too many
configurations
Can be tested
according UN
38.3
Has to be tested
according UN 38.3
Other
applications
Marine: too
large and
heavy for
testing
May be too heavy
for testing
Aviation: can be
tested according
to UN 38.3
Can be tested
according to UN
38.3
Has to be tested
according to UN
38.3
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Content:
1.
2.
3.
4.
5.
Examples of large batteries.
Batteries size and compatibility with tests.
Issues relative to 38.3.3 (f) and last § of 38.3.
Proposals for change of 38.3.3.
Proposals for change of définition of « battery
assembly » and « large battery »
6. Proposals for change of T.5 External short circuit
13
Issues relative to 38.3.3 (f) and last § of 38.3.
Text of reference:
(f) When testing a battery assembly in which the aggregate lithium content of all anodes,
when fully charged, is not more than 500g, or in case of a lithium battery, with a Watt-hour
rating of not more than 6 200 Watt-hours, that is assembled from cells or batteries that have
passed all applicable tests, one battery assembly at fully charged state shall be tested
under tests 3, 4 and 5, and, in addition, test 7 in the case of a rechargeable battery
assembly. For a rechargeable battery assembly, the assembly shall have been cycled at
least 25 cycles.
When batteries that have passed all applicable tests are electrically connected to form a
battery assembly in which the aggregate lithium content of all anodes, when fully charged,
is more than 500g, or in case of a lithium battery, with a Watt-hour rating of more than 6 200
Watt-hours, that battery assembly does not need to be tested if it is equipped with a system
capable of monitoring the battery assembly and preventing short circuits, or over discharge
between batteries in the assembly and any overheat or overcharge of the battery assembly”
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Issues relative to 38.3.3 (f) and last § of 38.3.
ISSUES:
1- There is a need to define “battery assembly” for large batteries, which
cannot be considered as a battery ( as stated in 38.3.2.2)
2- Transport safety protection is unevenly specified for Battery assemblies
depending on their energy:
- Over 6200 Wh, is specified a monitoring sytem (not active during transport),
but no test.
- Under 6200 Wh, a complementary test is specified, but no monitoring
system.
3- Multiple batteries configurations may lead to several test for same type of
battery using modules in series or in parallel: exemple: a cabinet of 6000 Wh
with 6 modules of 1000 Wh/12V may need to be qualified 4 times depending
on the serie/parallel configuration (6 S (72V), 2P 3S (36V), 3P 2s (24V), 6P
(12V)), although it represents the same risk when not connected.
4- Significant cost and duration of cycling for large batteries assembly under
6200Wh, for a test duplicating the test already requested at battery level.
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Content:
1.
2.
3.
4.
5.
Examples of large batteries.
Batteries size and compatibility with tests.
Issues relative to 38.3.3 (f) and last § of 38.3.
Proposals for change of 38.3.3.
Proposals for change of définition of « battery
assembly » and « large battery »
6. Proposals for change of T.5 External short circuit
16
Proposals for change of 38.3.3 (f) and last § of 38.3.
(f) When testing a battery assembly in which the aggregate lithium content of all anodes, when fully
charged, is not more than 500g, or in case of a lithium battery, with a Watt-hour rating of not more than 6
200 Watt-hours, that is assembled from cells or batteries that have passed all applicable tests, one
battery assembly at fully charged state shall be tested under tests 3, 4 and 5, and, in addition, test 7 in
the case of a rechargeable battery assembly. For a rechargeable battery assembly, the assembly shall
have been cycled at least 25 cycles.
When batteries* that have passed all applicable tests are electrically connected to form a battery
assembly in which the aggregate lithium content of all anodes, when fully charged, is more than 500g, or
in case of a lithium battery, with a Watt-hour rating of more than 6 200 Watt-hours, that battery assembly
does not need to be tested if :
- it is equipped with a system capable of monitoring the battery assembly and preventing short circuits, or
over discharge between batteries in the assembly and any overheat or overcharge of the battery
assembly.
-The batteries assembled are firmly secured to the mechanical structure of the battery assembly
-The design of the battery assembly integrates protections against the risk of dangerous heat propagation
from one battery to another inside the mechanical structure.
* Option A: for reasons of clarity, the word « battery » could be replaced by « battery
unit » or « battery-subassembly » in this text.
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Content:
1.
2.
3.
4.
5.
Examples of large batteries.
Batteries size and compatibility with tests.
Issues relative to 38.3.3 (f) and last § of 38.3.
Proposals for change of 38.3.3.
Proposals for change of définition of « battery
assembly » and « large battery »
6. Proposals for change of T.5 External short circuit
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Proposal for the definition of the “battery assembly”
• Definition of the « battery assembly »
•
Any set of “batteries”* and other components connected together
for usage, mechanically assembled and/or contained in a single
enclosure.
* Option A: definition of “battery-subassembly: a battery unit intended to be connected
with other battery-subassemblies and/or other battery components to form a battery for
purpose of usage
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Proposal for change of definition of “large batteries”
•
Issues for T2 Thermal test, T4: Shock test
Example battery of 3 cells with a mass > 500g and the total mass of the battery < 12kg: it
is a “small battery” assembled with “large cells”.
•Anomalies for T2 thermal test parameters between cells and batteries : time parameters
for small batteries not adapted for large cells.
•Anomalies between the shock test parameters between cells and battery: acceleration
for small batteries not adapted for large cells.
1. Proposal: complement in the definition of « large batteries »
« large battery means a lithium metal battery or lithium ion battery with a gross mass of
more than 12kg. »
Any battery assembled with large cells shall be considered as a large battery for testing
purpose.
When a large battery is assembled of small cells, these cells may be tested either as
large cell or as small cells for the purpose of the qualification of the battery.
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Content:
1.
2.
3.
4.
5.
Examples of large batteries.
Batteries size and compatibility with tests.
Issues relative to 38.3.3 (f) and last § of 38.3.
Proposals for change of 38.3.3.
Proposals for change of définition of « battery
assembly » and « large battery »
6. Proposals for change of T.5 External short circuit
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Proposal for change of the T.5: external short circuit.
•
Issue with T.5: Short circuit test.
• Tolerance for the temperature +55°C (+/-2°C) too tight
• Example: Thermal sensors at +/-2°C for temperature regulation
• In several standards +/-4°C rather than +/-2°C
• +/-2°C is a constraint for the test equipment
• Time of observation after the short-circuit implementation
• Most of the large batteries are equipped with circuit breaker or contactors system
to protect the battery; if the system is effective, the battery will immediately
open circuit and the short-circuit current is interrupted. Subsequent observation
time of a battery in open circuit has no technical utility.
• Proposal: for §38.3.4.5.2 Test procedure.
• In the text, replace « 55±2°C » with « 55±4°C »
• At the end of §38.3.4.5.2 , add the text:
For large batteries, check the voltage when the short circuit condition is removed.
If the battery is in open circuit, the further observation time can be reduced to one hour.
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