Interpretation Response #23-0029
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Northrop Grumman Corporation
Individual Name: Bob Keller
Location State: AZ Country: US
View the Interpretation Document
Response text:
June 20, 2023
Bob Keller
Avionics Design Group Director
Northrop Grumman Corporation
1575 South Price Road
Chandler, AZ 85286
Reference No. 23-0029
Dear Mr. Keller:
This letter is in response to your March 15, 2023, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to testing requirements for lithium ion battery packs in accordance with the United Nations (UN) Manual of Tests and Criteria in sub-section 38.3. You state that your company uses commercially available lithium ion cells for low-power battery packs where you have two basic battery configurations that are both enclosed in an aluminum housing. Configuration #1 is an 8-cell battery pack with a 100 Wh rating, and Configuration #2 is a 16-cell battery pack with an approximate 200 Wh rating. You seek confirmation of your understanding that you must test two units of each configuration in accordance with the requirements of sub-section 38.3.3(b), (d), and (f)—specifically, sub-section 38.3.3(b)(iii), (b)(iv), (d)(i), (d)(ii), and (f)—of the UN Manual of Tests and Criteria.
Based on the information you provided, your understanding is incorrect. In accordance with sub-section 38.3.3(b)(iii) and (b)(iv), an 8-cell battery pack with a 100 Wh rating must be tested under tests T.1 through T.5 in the quantity indicated:
- four small batteries at first cycle, in fully charged states; and
- four small batteries after 25 cycles ending in fully charged states.
Additionally, in accordance with sub-section 38.3.3(d)(i) and (d)(ii), an 8-cell battery pack with a 100 Wh rating must be tested under test T.7 in the quantity indicated:
- four small batteries at first cycle, in fully charged states; and
- four small batteries after 25 cycles ending in fully charged state.
In accordance with sub-section 38.3.3(f), if a 16-cell battery pack with a 200 Wh rating is assembled from two 8-cell battery packs that have passed all applicable tests, one assembled 16-cell battery pack in a fully charged state shall be tested under tests T.3, T.4, T.5, and T.7. Alternatively, the 16-cell battery pack may be tested in accordance with sub-section 38.3.3(b)(iii) and (b)(iv) using quantities indicated in the sub-section. Please note that small batteries not equipped with battery overcharge protection that are designed for use only as a component in another battery or in equipment—which affords such protection—are not subject to the requirements of the T.7 testing requirements.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division