"MADE IN JAPAN" – a mark of trust and reliability

By integrating the extensive knowledge and specialized expertise that Hero Electric has cultivated over more than half a century into every aspect of the design phase—and manufacturing exclusively at domestic facilities under innovative technologies and a rigorous, comprehensive quality control system—we achieve exceptionally high precision and reliability in the products themselves.

To meet the supreme mission of achieving both "quality" and "durability" as professional-use products, all of our products are designed and developed entirely in-house.

Uses Oxygen-Free Copper (OFC) with impurities removed to the utmost limit

For the first time in Japan's automotive aftermarket industry, we adopted Oxygen-Free Copper (OFC) as the core material for our battery terminal bodies. OFC is significantly purer and more conductive than standard copper, and is widely used in electronics and high-performance cables.

Images are for illustration purposes.
Not available for sale in bare (non-plated) form.

What is Oxygen-Free Copper (OFC) ?

High-purity copper with a purity of 99.96% or more

Oxygen-Free Copper is an exceptionally pure type of copper with minimal trace elements, impurities, and oxygen, resulting in a significantly higher purity compared to general copper.

High Electrical Conductivity

Oxygen-Free Copper has excellent electrical conductivity and is widely used in electronics, wiring, and conductors. Its high conductivity allows efficient transmission of electrical signals.

[Reference] Comparative Table of Conductivity of Various Materials Commonly Used for Battery Terminals

*1. IACS refers to the International Annealed Copper Standard, which defines 100% IACS as the conductivity of annealed standard copper.
*2. The above values are general reference values and not absolute (guaranteed) values.
(*Note) Cu-Zn alloys are referred to as brass; the academic term is "黄銅" (ōdō).
　　　　　(Reference): Osawa, Nao. "Illustrated Introduction to the Basics and Mechanisms of Copper." Shuwa System, 2010, p.106.

[Point] Easy-to-understand conductivity explained with illustrations

Conductivity can be compared to "road width," where smoother traffic flow represents higher efficiency.

Copper is a critical material for realizing a sustainable, decarbonized society through renewable energy and electric vehicles

■Renewable Energy Generation
Copper plays a vital role in renewable energy systems. Solar and wind power equipment requires large amounts of copper wiring. Copper's high conductivity and durability enhance the efficiency and sustainability of renewable energy generation.

■Electric Vehicles and Charging Infrastructure
Copper is an essential material in the production of electric vehicles. Motors, batteries, and charging infrastructure for electric vehicles require large amounts of copper. Its excellent conductivity and durability contribute to improved performance and efficiency in electric vehicles.

■Electronic Devices
Copper is also essential in electronics manufacturing. Copper wiring is used in computers, smartphones, and TVs. Its excellent heat conduction makes it suitable for use in cooling systems. As high-performance electronics become increasingly important in a decarbonized society, copper plays a crucial role in supporting this demand.

The surface is treated with 24K gold plating, which not only preserves low contact resistance but also delivers outstanding corrosion resistance and a lustrous, refined appearance

For the surface treatment of oxygen-free copper (OFC), we employ 24K gold plating—renowned not only for its elegant appearance, but also for its exceptionally low contact resistance, superior chemical stability, and outstanding corrosion resistance. This high-grade plating is the same type used in partial plating of specialized automotive airbag connectors, as well as in precision electronics, semiconductor manufacturing equipment, and measurement instruments.

About Gold Purity

Gold purity (or fineness) is a measure of the amount of gold in a product, expressed as a percentage (%) or in karats (K, kt). Pure gold is 24 karats, which means it contains 99.9% to 100.0% gold.

■ Gold Purity Explained at a Glance

Note: Common metals used as gold alloys include silver, copper, palladium, nickel, and zinc.

(Reference) TANAKA Holdings Co., Ltd. “Interesting Facts About Precious Metals - Is it true that the higher the gold purity, the softer it is?” https://www.tanaka.co.jp/fun_facts/gold_purity/. (Accessed on 2024-04-17)

Developing products with a strong emphasis on unleashing maximum performance

To ensure the highest priority of achieving both reliability and robustness as battery terminals under the extremely harsh conditions of automotive engine compartments, we have established key specifications that include thickened materials and a slitless structure—free from notches or cracks. From the design stage onward, our in-house product development integrates the technical expertise and know-how that Hero Electric has cultivated over the years.

Thickness Verification of Oxygen-Free Copper (OFC) Battery Terminals

Products	Plate Thickness
Bolt-Type Model	DTPL Series	1.8 mm (0.071 in)
	DTPS Series	1.5 mm (0.059 in)

(Dimensional tolerance: ±0.1 mm / ±0.004 in)

[Reference] Validation Based on Real-World Use Cases of Slit-Type Battery Terminals

Slits (cuts or cracks) can weaken the strength of objects or structures. When external force or load is applied to the slit, that area may become a point of weakness, increasing the likelihood of cracking or breakage.

Furthermore, Slit-type battery terminals that develop cracks due to vibrations from automobiles may cause unexpected vehicle issues, as increased contact resistance or poor connections can lead to voltage drops.

Verified by "Vibration Test" Based on JIS Standards (Test materials: DTPL and DTPS)

[Overview of Vibration Testing Equipment]

Dedicated Page for Disclosure of Performance Testing Information

Actively promoting environmentally conscious manufacturing with consideration for issues such as climate change and biodiversity conservation

We place great importance on environmentally conscious manufacturing. As part of this commitment, over 30 years ago, Hero Electric took the lead in developing oxygen-free copper (OFC) battery terminals for automotive aftermarket use—completely free from hazardous substances such as lead, mercury, and cadmium—in compliance with the RoHS2 Directive. In line with RoHS2, Hero Electric will continue to actively contribute to global environmental preservation by providing compliant products and working toward a more sustainable future.

The RoHS2 (Restriction of Hazardous Substances Directive) is a directive issued by the European Union (EU) that restricts the use of specific hazardous substances in electrical and electronic equipment and their components. The goal of RoHS2 is to reduce harmful effects on both the environment and human health.

The ten substances restricted under the RoHS2 Directive are as follows:

1. Lead
2. Mercury
3. Cadmium
4. Hexavalent Chromium
5. Polybrominated Biphenyls(PBBs)
6. Polybrominated Diphenyl Ethers(PBDEs)
7. Diisobutyl phthalate(DIBP)
8. Dibutyl phthalate(DBP)
9. Butyl benzyl phthalate(BBP)
10. Bis(2-ethylhexyl) phthalate(DEHP)

These substances are recognized as harmful to the environment, particularly when they leak during waste disposal, potentially contaminating soil and water sources and negatively impacting ecosystems and human health.

Hero Electric's Exclusively Designed Battery Terminal Cover — Where Function Meets Form

To improve usability, HERO Electric has expanded its original battery terminal cover series by introducing dedicated covers designed to fit both types of oxygen-free copper (OFC) battery terminals—standard and conversion models. These covers have been developed using HERO’s proprietary technologies and know-how, refined over many years, while also pursuing a sophisticated and functional design. In order to ensure high product reliability, domestic production is maintained without compromise. Like other products in the lineup, the covers feature increased wall thickness for enhanced durability and safety.

Cover for Oxygen-Free Copper (OFC) Battery Terminal – Bolt Type (Compatible with DTPL and DXL models)

Cover for Oxygen-Free Copper (OFC) Battery Terminal – Bolt Type (Compatible with DTPS and DXS models)

Verification Results of Leakage Current Testing Based on Our In-House Standards (Test Material: DVCP60)

[On-Vehicle Installation Example of Dedicated Cover for Oxygen-Free Copper (OFC) Battery Terminals]

State During Testing
 

Dedicated Page for Disclosure of Performance Testing Information