1. UL and the UL logo are trademarks of UL LLC © 2015 UN38.3 Disassembly definition 2016-03 Copyright © 2015 UL LLC. All rights reserved.

2. Disassembly current definition 2 Disassembly means a vent or rupture where solid matter from any part of a cell or battery penetrates a wire mesh screen (annealed aluminium wire with a diameter of 0.25 mm and grid density of 6 to 7 wires per cm) placed 25 cm away from the cell or battery. Disassembly as a compliance criteria:

3. Examples of standards where wire mesh is used 3 UL1642 – Projectile test only UL2054 – Projectile test only Comments to use wire mesh cage: 1.the use of the aluminum wire mesh cage is problematic and not the most reproducible of tests 2.projectile test is the only one allowed to be repeated in UL 1642, if there is an failure in the first set of cells tested 3.it is not always clear whether the fragments have penetrated the cage because of force or just burned through

4. Proposal one for new definition 4 Disassembly means a vent or rupture where solid matter from any part of a cell or battery penetrates a wire mesh screen (annealed aluminium wire with a diameter of 0.25 mm and grid density of 6 to 7 wires per cm) placed 25 cm away from the cell or battery. is forcibly expelled.

5. Proposal two for new definition 5 Disassembly means a vent or rupture where solid matter from any part of a cell or battery is forcibly expelled, additionally during cell or component cell testing expelled components penetrates a wire mesh screen (annealed aluminium wire with a diameter of 0.25 mm and grid density of 6 to 7 wires per cm) placed 25 cm away from the cell or battery.

6. Additional rationale for proposal two 6 1. Testing difficulties: a. there are variety of different sizes and shapes of battery packs, b. construction is not precisely described – orientation of sample during testing may influence a test result, c. it requires a lot of space to keep batteries for 7 days after T7 test and 8 samples for each model of small battery pack (minimum space required 0,5m x 0,5m = 0,25sqm per sample means 2sqm + eight wire meshes per tested model) 2. Limited benefit: For battery packs, Disassembly definition is important for External Short Circuit (T5) and Overcharge (T7) tests (tests T1-T4 has leakage criteria more difficult to comply with). At the same time battery packs shall be protected against such condition. Taking this into consideration after T5 and T7 tests batteries should remain intact due to implemented protection.