Application Case: Battery Busbar and Weld Resistance at Module Build

An anonymous battery-module workflow showing how a portable resistance meter, stable fixturing, and temperature compensation made joint measurements usable in engineering and pilot production.

Last updated: 2026-09-18

Project context

A lithium battery module line was moving from engineering samples to a pilot run. Each module contained copper busbars and welded interconnects. The quality team had been measuring selected joints with a handheld meter, but results shifted when the operator moved the clips or when the module temperature changed. Procurement was asked for a 'micro-ohmmeter with the highest resolution,' which would not fix the method problem.

The normal production workflow

After welding and visual inspection, the module is placed in a locator. The operator connects force and sense contacts to the defined busbar points, records the module identifier, measures the joint, and routes an outlier to rework review. Engineering then uses the same connection geometry for sample correlation work. This workflow only works when the current path and voltage-sense points are consistent.

Equipment selected

The project selected a Hioki RM3548-50 type resistance meter for portable four-terminal checks. Its published 0.1 micro-ohm resolution, 1 A maximum test current, temperature-correction capability, comparator functions, and data storage match a controlled module-inspection method. The team used its supplied temperature measurement as a reference and defined a fixed ambient stabilization time before inspection.

For a higher-volume automated line, the same project plan identified a bench resistance meter with external I/O and a dedicated fixture as the next step. That decision depends on throughput, probe life, and traceability, not merely on a lower displayed digit.

Result in use

The first repeatability study showed that several apparent outliers came from lead contact placement. The team improved the locating fixture and contact-cleaning rule before changing weld parameters. Once the method was frozen, actual high-resistance joints were easier to identify and review alongside weld images.

What to verify before publishing

Confirm the target resistance range and production test current against your real module drawing and applicable safety/quality process. This is an anonymous industry scenario and a real equipment recommendation, not a named customer's reported installation.