Product Feb. 14, 2022

Hioki to Launch Three Battery Quality Testers in 2022 in Drive to Eliminate Battery Fires

Hioki is pleased to announce that in 2022 it will launch three new measuring instruments designed to detect latent defects in quality inspections on battery production lines. The company’s goal is to increase the safety of lithium-ion batteries, for which demand is growing worldwide.

Advance information about the new products is available on a special website.
Hioki plans to make more details available in April.

Click here for the special site

Development background

Initiatives centered on moving society beyond its dependence on carbon-based fuels are gathering pace as countries worldwide work to achieve carbon neutrality by 2050. Major automakers’ ongoing shift to electric vehicles, which do not emit CO2, is pushing up demand for the lithium-ion batteries (LiBs) that power them.

However, the risk of fires caused by defective batteries is rising even as LiBs enrich consumers’ lives.

Fire risk 1: Insulation defects

Inside an LiB, the positive and negative electrode sides of the battery are filled with different electrolytes and insulated by a separator. Contamination with iron powder or the formation of burrs during the manufacturing process can gradually damage the separator, creating minuscule insulation defects where a short-circuit current can flow, generating heat. If the separator tears, a large current will flow, creating heat that exceeds design parameters. The resulting thermal runaway state could cause a fire by igniting the electrolyte.

Fire risk 2: Weld defects

The materials that make up an LiB are welded together with metal to facilitate the flow of current. Poor-quality welds have a higher resistance component that impedes current flows, resulting in heat loss. Heat loss not only reduces the battery’s thermal efficiency, but also impacts safety due to the potential of heat to lead to degradation and eventual failure. Because the welds in LiBs used in electric vehicles carry large currents during rapid charging and while driving, even a minuscule weld defect can cause extreme heating and fire.

Developing instruments that can detect the causes of defects

To address these risks, Hioki will make it possible to produce highly safe batteries by launching instruments capable of detecting the causes of defects that can lead to fires. By driving quality improvements in testing on battery production lines as the global market for LiBs grows, the company is helping realize a decarbonized society in which people can live with greater peace of mind.

Product features


The BATTERY INSULATION TESTER BT5525 can detect internal short-circuits, which can cause overheating and fire, at the LiB cell production stage. Thanks to its extremely high level of detection precision, the instrument can detect minuscule shorts caused by phenomena such as contamination with metallic material and tears in insulators, which have been difficult to detect until now.


The DC HIPOT TESTER ST5680 can generate pass/fail judgments based on the state of insulation in finished LiBs after packaging. Furthermore, it can display and record test results as waveforms. By helping operators analyze the causes of defects after testing, the instrument can lighten the workload of quality control personnel.


The WELDING RESISTANCE METER RM3546 can generate pass/fail judgments based on the quality of welds joining materials that make up LiBs. Thanks to the instrument’s extremely high level of measurement performance, it can detect even minuscule weld defects. In addition, correction functionality that allows new welds to be accurately measured even while still hot makes it possible to inspect parts without first waiting for them to cool.

Principal applications

Insulation resistance testing, withstand voltage testing, weld quality testing, and other inspections in LiB production processes


Coming in 2022