Equipment OEM engineers and compliance managers buy custom lithium packs for medical, robotics, security, infrastructure, and industrial devices. These buyers face a different burden than retail replacement shoppers. Every custom configuration and revision raises the chance of a document mismatch. Three checks cut through that risk fast. First, verify the model number on the UN 38.3 Test Summary against the pack label. Second, compare the technical specifications across the datasheet and the summary. Third, cross-check every document detail, including manufacturer, laboratory, and report references. Run these checks in the same order each time. A repeatable routine turns a slow review into a quick, confident release decision.
Key Takeaways
Verify the model number on the UN 38.3 Test Summary matches the pack label exactly.
Compare technical specifications like mass and watt-hours across the datasheet and summary.
Cross-check manufacturer, laboratory, and report references for consistency.
Follow a fixed checklist for every incoming custom pack to catch revision gaps early.
Record all verification details to support audits and speed future inspections.
Part 1: Reading the UN 38.3 Test Summary
1.1 What Subsection 38.3.5 Requires
Subsection 38.3.5 of the UN Manual of Tests and Criteria specifies the lithium cell and battery test summary. Review the applicable test list and results for the design; the summary is not limited to T.1 through T.4. It is distinct from the detailed test report.
The summary carries the manufacturer name, the laboratory that performed the testing, report references, a physical description of the battery, and the model identity. Each field exists so a reviewer can trace the summary back to the full record. A complete UN 38.3 Test Summary lets an OEM confirm that the tested design matches the pack in the box.
1.2 Summary vs. Full Report and SDS
These documents serve different purposes, and mixing them up causes review errors. The full test report holds the raw procedures, measurements, and laboratory observations. The summary extracts the key identifiers from that report. The SDS is a separate chemical safety document, and it follows a different logic:
An SDS describes physical and chemical properties, health hazards, storage, disposal, and first-aid measures. A manufacturer or third party can prepare it without running tests.
The UN 38.3 Test Summary reports targeted transport-safety testing, including lab identity and a unique test report ID.
Shipment documentation covers the declared dangerous goods classification and packaging for a specific consignment.
A test summary alone does not authorize transport. Carriers and regulators expect the shipper to hold the supporting records and to declare the shipment correctly. OEM buyers should file the summary beside the full report and the SDS, then confirm that all three describe the same pack.
Part 2: Checking Model Identity on the UN 38.3 Test Summary
2.1 Matching Model Number to Pack Label
Confirm that the delivered model is traceably covered by the tested design. Where label and report identifiers differ, request documented model-family or private-label mapping. An unexplained mismatch blocks acceptance; a harmless formatting difference does not by itself prove a different design.
Compare the finished pack identity and technical description with the summary and supporting report references. Confirm which design the evidence covers. Check shipment documents separately under the actual transport mode and applicable rules; they are not interchangeable with the test summary.
Confirm whether the evidence describes a cell, a battery or an assembled battery. Escalate uncertain coverage to a qualified dangerous-goods specialist or the testing organization.
2.2 Confirming Against the Datasheet
Cross-check shared fields such as model, mass, battery type and energy rating. Dimensions and BMS details may help identify the design, but they are not necessarily separate mandatory summary fields. Request supporting drawings or specifications when needed.
Cell specifications and pack specifications are not the same thing. A cell-level test report covers the cell design. It does not automatically cover a custom pack that adds a BMS, a different enclosure, or a new connector layout. The pack builder must show that the tested design corresponds to the delivered configuration. Reviewers should ask for the pack-level summary whenever the custom build differs from the tested cell platform. The BMS and PCM page at large-battery.com explains how protection circuits change pack-level behavior.
Verify manufacturer and test-facility identity and contact details, report number, report date and the edition of the Manual used. Check the applicable summary requirements rather than imposing an assumed universal certificate format.
Keep internal review records under the OEM document-control process. Protect commercially confidential information when sharing documents, while retaining necessary traceability and legally required information.
Part 3: Verifying Document Consistency
3.1 Comparing Technical Specifications
A field-by-field comparison turns document review into a mechanical task. The reviewer places the UN 38.3 Test Summary, the datasheet, and the certification documents side by side. Each shared field must agree across all three. The table below lists the fields that matter most for a custom pack.
Compare mandatory summary fields with the supporting documents wherever they overlap. Use drawings and configuration records for additional engineering identification, without presenting those extra records as universal summary fields.
Consider an illustrative case. A pack datasheet lists a nominal voltage and a watt-hour rating. The summary lists a slightly different mass because the tested unit carried a different enclosure. That gap is not automatically a failure. It is a signal that the reviewer must confirm which configuration the laboratory tested. Any numeric example here is illustrative only. Real values depend on the actual cell datasheets and on system validation.
Pack-level specifications deserve special attention. The BMS and PCM page at https://www.large-battery.com/bms-and-pcm/ explains how protection circuits shape overcurrent, overvoltage, and thermal behavior. A summary that covers a bare pack may not cover a version with an added BMS board. The reviewer should confirm the summary names the protected configuration when the delivered pack includes one.
3.2 Cross-Checking Certification and Revisions
Revision control is where custom packs drift. A connector swap, a new enclosure, or a changed cell supplier can all alter the tested design. The reviewer should compare revision codes across the summary, the datasheet, and the certificate. Matching revision strings build confidence. Divergent strings demand a written explanation from the supplier.
Changes require qualified assessment. They do not trigger automatic retesting of every minor modification. A qualified assessor weighs the nature of the change against the tested design and decides whether the existing evidence still applies. An OEM engineer should ask for that assessment in writing and file it with the verification record.
UN 38.3 evidence is not necessarily issued as a certification with a fixed validity period. Verify design coverage, test records and applicability; do not treat a generic certificate as a substitute for a complete summary.
A clean cross-check ends with a short record. The engineer logs the model identity, revision code, certificate reference, and the assessor’s conclusion. This record supports future audits and speeds the next incoming inspection.
Part 4: Common Pitfalls and Red Flags
4.1 Typical Mismatches
Common discrepancies include obsolete revision references, unexplained model mapping, inconsistent mass or energy ratings, and missing test-facility identification. Use documented examples from the actual project rather than assuming an unverified shipment-delay story is evidence.
Cell testing does not automatically establish finished-pack compliance. Conversely, an added connector or BMS does not automatically mean every test must be repeated. Determine the applicable battery or assembled-battery requirements and assess the actual modification.
Chemistry labels deserve a check too. A summary that names LiFePO4 while the datasheet lists NMC, LCO, or LMO signals a documentation error or a design change. Either way, the reviewer needs clarification before release.
A document may cover more than one model when the coverage and design relationship are valid and documented. The reviewer must establish that the delivered configuration is included.
4.2 When to Escalate
Some findings warrant a formal escalation rather than a quick email. An engineer should escalate when the model number on the summary differs from the pack label, when only cell-level documents exist for a custom pack, or when the laboratory cannot confirm the report reference. The same applies when a supplier refuses to identify the cell model or changes specifications between quotation and sampling.
Escalation means pausing the release and requesting the full test report, the current summary, and a written assessment from a qualified person. The reviewer documents the discrepancy, the supplier response, and the resolution date. This record protects the project and speeds the next audit.
Part 5: OEM Verification Checklist
5.1 Step-by-Step Checks
Use a controlled checklist at initial supplier qualification and after relevant changes. Determine incoming verification frequency from risk, supplier controls and the quality agreement.
Confirm the model identity on the UN 38.3 Test Summary covers the delivered label model and applicable revision through documented mapping.
Confirm the manufacturer name for both the cell and the pack assembler, and check that each name matches the datasheet.
Confirm test-facility identity and the acceptability of the supporting evidence for the applicable requirements.
Confirm the report reference traces to a full test report the supplier can produce on request.
Confirm the physical description, including mass, dimensions, and watt-hour rating, agrees with the datasheet.
Confirm the summary is complete, with all subsection 38.3.5 fields filled and no blank entries.
A complete and consistent summary satisfies only one part of the release review. It is not sufficient on its own to approve a battery design, equipment integration or transport consignment.
5.2 Recording and Handling Discrepancies
Record the model mapping, design revision, report reference, review date, reviewer and any supporting assessment. Keep the record with controlled procurement and compliance files.
A discrepancy follows a defined path. The reviewer logs the exact field that failed, notifies the supplier in writing, and pauses the release. The supplier then supplies a corrected summary, a written assessment from a qualified person, or both. The reviewer closes the record only after the evidence arrives and matches the delivered pack.
A test summary is a design-type document. It supports a release decision but never authorizes transport on its own.
Engineers should apply this checklist to every incoming custom pack, not just the first shipment. Consistency across lots catches revision drift early and keeps the verification file complete.
Three checks carry the review. Verify model identity against the pack label. Compare specifications across the datasheet and the summary. Cross-check every document detail, including manufacturer, laboratory, and report references. Together they turn a custom pack review into a fast, repeatable routine.
The UN 38.3 Test Summary is a design-type document. It supports a release decision but never authorizes transport on its own. Design changes need a qualified assessment, not automatic retesting of every minor modification. Apply the checklist to every incoming custom pack and record the results. Consistent records catch revision drift early and keep the verification file audit-ready.
FAQ
Does a UN 38.3 Test Summary expire?
The summary itself carries no fixed expiry date. Reviewers instead confirm that the tested design still matches the delivered pack. A revision change, a new cell platform, or a different enclosure can break that match. The reviewer then requests a written assessment from a qualified person and files it with the verification record.
Can a cell test report cover a finished custom pack?
Not automatically. A cell-level report covers the cell design alone. A custom pack adds a BMS, an enclosure, and connectors that the cell test never exercised. The pack builder must show that the tested design corresponds to the delivered configuration. Reviewers should request the pack-level summary whenever the build differs from the tested cell platform.
Who performs the qualified assessment after a design change?
A qualified person with the technical background to judge the change against the tested design performs it. The assessor weighs the nature of the modification and decides whether the existing evidence still applies. OEM engineers should request that judgment in writing and keep it beside the summary, the full report, and the SDS.
What belongs in the verification record?
The record stays short and shareable. It lists the model identity, the revision code, the cell and pack manufacturer, the laboratory, the report reference, the physical description, and the reviewer’s name and date. Handle confidential project information under the OEM document-control policy.
Does a complete summary clear a shipment for transport?
No. The summary is a design-type document. It supports a release decision but never authorizes transport on its own. Shippers must hold the supporting records and declare each consignment correctly under the applicable dangerous goods rules.
Part 6: Official Sources and Document Fields
PHMSA test-summary guidance and its January 2026 interpretation provide official references. Check manufacturer and test-facility contact details; report number and date; battery description and identity; applicable test information; assembled-battery references where relevant; the Manual edition; and responsible-person information. Apply the exact requirements for the jurisdiction and transport mode.
