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Interpretation Response #06-0141 ([LG Chem/Mobile Energy Company] [Hyeong " Jin Kim, Ph.D. ])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: LG Chem/Mobile Energy Company

Individual Name: Hyeong " Jin Kim, Ph.D. 

Location State: TX Country: US

View the Interpretation Document

Response text:

Oct 25, 2006

Hyeong – Jin Kim, Ph.D.                 Reference No. 06-0141
General Manager
LG Chem/Mobile Energy Company
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 with 38.3.4.7.2 of the UN Manual of Tests and Criteria, which is referenced in the Hazardous Materials Regulations (HMR; CFR parts 171-180). Specifically, you ask whether your procedures are correct in accordance with Test T.7 of the UN Manual of Tests Criteria.

According to your letter, your lithium-ion battery has a nominal capacity of 650 mAh (1C) and a maximum voltage charge of 4.2 V. During testing of your lithium-ion batteries, they are charged continuously at 1.3 A for a period of 24 hours with a select voltage range between 8.4 and 22 volts.

Section 38.3.4.7.2 reads: “The charge current shall be twice the manufacturer’s recommended maximum continuous current.” ‘Therefore, your choice of 1,300 milliamp-hours (1.3 amp-hours) for the maximum charge current of the T.7 Test is correct.

Section 38.3.4.7.2 continues: “The minimum voltage of the test shall be as follows: a) when the manufacturer’s recommended charge voltage is not more than 18V, the minimum voltage of the test shall be the lesser of two times the maximum charge voltage of the battery or 22V.” It is your understanding, based on 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 conclusion 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,

 

John A. Gale
Chief, Standards Development
Office of Haza4dous Material Standards

173.185

Regulation Sections