LG Chem/Mobile Energy Company — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department 400 Seventh Street, S.W. Washington, D.C. 20590 Pipeline and Hazardous Materials Safety Administration OCT 25 2006 Hyeong-Jin Kim, Ph.D. Ref. No.: 06-0141 LG Chem/Mobile Energy Company General Manager 20445 SH249, Suite 250 Houston, TX 77070 Dear Dr. Kim: This is in response to your letter requesting clarification of the requirements for Test T.7 overcharge procedures and conditions applicable to lithium-ion batteries in accordance referenced in the Hazardous Materials Regulations (HMR; CFR with 38.3.4.7.2 of the UN Manual of Tests and Criteria, which is are correct in parts 171-180). Specifically, you ask whether your procedures Tests Criteria. accordance with Test T.7 of the UN Manual of According to your letter, your lithium-ion battery has a nominal During testing of your lithium-ion batteries, they are charged capacity of 650 mAh (1C) and a maximum voltage charge of 4.2 V. voltage range between 8.4 and 22 volts. continuously at 1.3 A for a period of 24 hours with a select manufacturer's recommended maximum continuous current." Section 38.3.4.7.2 reads: "The charge current shall be twice the Therefore, your choice of 1,300 milliamp-hours (1.3 amp-hours) mum chase current of the 7. 7 tost ta Crocours Section 38.3.4.7.2 continues: "The minimum voltage of the test charge voltage is not more than 18V, the minimum voltage of the shall be as follows: a) when the manufacturer's recommended test shall be the of the battery or 22V." It is your understanding, based on lesser of two times the maximum charge voltage 38.3.4.7.2, that you may use an arbitrary number between 8.4V and 22V with which to conduct the T.7 Test the batteries described above. The language of Section 38.3.4.7.2 would not appear to allow the person testing a battery an arbitrary choice between the two voltages (8.4V and 22V). However, it is our 173.185 060141#

Page 2conclusion that testing the battery at a higher voltage than is actually required will not invalidate the test. I hope this information is helpful. If you have further questions, please do not hesitate • to contact this office. Sincerely, MAG SA Office of Hazardous Materials Standards Chief, Standards Development#

Page 3Relerford $173.185 Lithium Batteries 20445 SH249, SUITE 250 06-0141 HOUSTON, TX 77070 TEL. 281 376 0963 FAX 281 257 1250 LG CHEM June 26th, 2006 Mr. Edward T. Mazzullo Director, Office of Hazardous Materials Standards 400 7th Street S.W. U.S. DOT/PHMSA (PHH-10) Washington, D.C. 20590-0001 Dear Mr. Edward T. Mazzullo This is Hyeong-Jin Kim in LG Chem., one of lithium ion battery manufactures. transport of dangerous goods (HMR; 49 CFR Part 173.185 - Li ion batteries section, Manual of tests and I am writing this mail for clear understanding for the UN testing Manual of Test and Criteria, a requirement criteria, Ch 38.3 ). Lithium batteries.. Questions are about the UN DOT test procedure and condition for Test T.7, overcharge test item regarding First, here is general information for battery. - Max. charge voltage: 4.2 V, Nominal capacity: 650 mAh(1C). - Two times the maximum voltage: 8.4V, twice maximum continuous charge current: 1.3A (according to the UN overcharging test procedure, 38.3.4.7) maximum charge voltage of the battery or 22 V. In my understanding for the sentence, a tester can choose In accordance with the test procedure for T7(38.3.4.7.2), the minimum voltage is two times of the an arbitrary number between 8.4 V and 22 V for the supplying voltage. batteries are charged continuously with 1.3 A for 24 hours. For example, we do the test like this. One of voltages between 8.4 V and 22 V (i.e. 22 V) is set up and then unclear points to us. Your clarification is urgently needed for the further progressing. Currently, we are testing the batteries according to UN DOT test manual and T.7 test method has some If you possible, we'd like to have the answer thru express mail or fax machine directly. I am look forward to obtaining your confirmation for our overcharge test procedure as soon as possible. Thank you for your cooperation. Sincerely yours, roger fiC Hyeong-Jin Kim, Ph.D. General Manager Battery C/S team, Mobile Energy Company#