Informal working group Large Lithium batteries testing RECHARGE

Informal working group: Large Lithium batteries testing RECHARGE & SAFT Washington, Oct. 2 nd 2013 1

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 2

Examples of “large batteries” Stationary Electro. Mobility 3

Boundaries of an Industrial Battery for E-mobility 4

Boundaries of an Industrial Battery for E-mobility Inner jacket Cell Module Inner jacket stack 5

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 8

Other types of industrial batteries ü Aviation batteries, ü Tram/ Railways batteries, ü 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. 11

What can be tested for safety during transport? 12 kg limit? 6200 Wh limit? Batt type Very large assembly Automotive Large Battery assembly Modules, stacks, Cells intermediate Battery pack: Truck and buses batteries may be too heavy Battery pack: 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 12

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 500 g, 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 500 g, 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” 14

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/12 V may need to be qualified 4 times depending on the serie/parallel configuration (6 S (72 V), 2 P 3 S (36 V), 3 P 2 s (24 V), 6 P (12 V)), although it represents the same risk when not connected. 4 - Significant cost and duration of cycling for large batteries assembly under 6200 Wh, for a test duplicating the test already requested at battery level. 15

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 500 g, 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 500 g, 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. 17

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 18

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 19

Proposal for change of definition of “large batteries” • Issues for T 2 Thermal test, T 4: Shock test Example battery of 3 cells with a mass > 500 g and the total mass of the battery < 12 kg: it is a “small battery” assembled with “large cells”. • Anomalies for T 2 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 12 kg. » 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. 20

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 21

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. 22