Open a Formal Change Record

Require the reason for change, proposed supplier and part number, affected models, affected purchase orders, last old-pack lot, first new-pack lot, timeline, risk assessment, sample plan, document owner, and rollback or containment plan. Do not let procurement substitute the pack only through a quotation note.

The speaker change-request process provides a structure for connecting engineering evidence to the order.

Compare the Pack as a Controlled Assembly

Review drawings, BOM, labels, dimensions, weight, connector keying and polarity, wire gauge and length, insulation, mounting, pressure or abrasion points, cell configuration, BMS, protective devices, temperature sensor, pack firmware if any, and supplier process.

Verify Documents Against the Exact Pack

Check that reports and summaries identify the cell or battery type actually proposed. UN Manual of Tests and Criteria subsection 38.3 addresses lithium battery transport testing, and the current revision and amendment should be reviewed for the shipment. IEC 62133-2 addresses safety requirements for portable sealed lithium cells and batteries, but market requirements and certification routes vary.

Do not treat a cell report as proof for every assembled pack or a family document as automatic coverage. Ask a qualified compliance and logistics party to confirm the exact product, pack, route, carrier, destination, and current document set before shipment.

Run Product-Level Charge and Load Tests

Install the pack in production-intent speakers. Verify connector insertion, polarity protection, retention, clearance, padding, wire routing, enclosure closure, service access, and no compression or sharp-edge contact. Then use the approved charger and product firmware for charging, rest, playback, peak load, low-battery, shutdown, recharge, and repeated-cycle observations.

The battery-runtime guide helps preserve the conditions behind any runtime comparison.

Compare Variation, Not Only Two Samples

Use an agreed number of packs and cells from representative lots. Compare capacity, internal resistance where appropriate, weight, open-circuit voltage, charge behavior, load sag, runtime, threshold behavior, temperatures, and assembly fit. Define measurement method and equipment capability before setting tolerances.

An unusually strong engineering sample does not establish production consistency. Require supplier control records and lot traceability, then repeat critical incoming and product checks on the first production lots.

Assess Safety and Product Interactions

The battery-management article explains the system relationship among cell, BMS, charger, firmware, amplifier, enclosure, and thermal design. A pack change can require safety, EMC, transport, label, manual, package, or certification review even when nominal ratings stay the same.

Do not modify protection thresholds to recover runtime or output without a complete engineering and compliance assessment. The change can move risk from user experience into cell stress, wiring, connector, semiconductor, or enclosure heat.

Release by Lot and Preserve the Cutover

Approve the supplier, part number, drawing, BOM, documents, inspection plan, golden sample, first-lot sampling, affected order, and cutover date. Keep old and new stock segregated. Update service parts and support diagnosis so returned units receive a compatible pack.

Review quotation, MOQ, sample cost, lead time, certification, packaging, freight, inventory, after-sales, and warranty before approving the substitution. Do not mix pack versions under one code if traceability and service cannot distinguish them.

Battery Change Qualification Record

• Reason, scope, affected models/orders, old-last lot, new-first lot, and containment are documented.
• Cell, configuration, BMS, protection, wiring, connector, mechanics, labels, and supplier controls are compared.
• Safety and transport records match the exact proposed pack and current route requirements.
• Fit, charge, runtime, peak load, low battery, shutdown, recovery, and standby are tested in the product.
• Multiple packs and representative lots are reviewed with capable measurement methods.
• Certification, labeling, packaging, freight, cost, lead time, service, and warranty effects are approved.
• Old and new inventory remain segregated and traceable through production and after-sales.
• First production lots repeat critical incoming and product-level checks.

References

• United Nations Economic Commission for Europe, UN Manual of Tests and Criteria, Revision 8 and Amendment 1.
• International Electrotechnical Commission, IEC 62133-2:2017 with Amendment 1:2021 — portable lithium cell and battery safety.