Government of Canada investing $6.5M in five next-generation auto R&D projects; total project value of $16M
RøhneSelmer in Norway places early repeat order for 100 more Transit Connect Electric vans

Hitachi Cable develops smallest compact connectors yet for use in power harnesses for hybrid and electric vehicles; some 40% reduction in connector volume

Comparison of the volume of a newly developed connector to that of a traditional connector. Source: Hitachi Cable. Click to enlarge.

Hitachi Cable, Ltd. has developed what it says are the world’s smallest compact connectors (as of 28 June, based on its research) for use in power harnesses for hybrid electric vehicles and electric vehicles.

The drive systems of these vehicles consist of electric motors, inverters, batteries, and AC and DC harnesses connecting these electrical devices. Given the limited space for wiring and high-temperature conditions inside engine compartments, these harnesses must provide outstanding high-temperature resistance and flexibility.

Used in numerous vehicle models, the power harnesses already developed by Hitachi Cable include cables made of Hitachi’s Fluonlex fluorine resin, a material that confers superior heat resistance and flexibility, and halogen-free, heat-resistant cables offering improved heat resistance (capable of withstanding temperatures up to 150 °C) through unique compounding technologies.

New connector at left, traditional connector at right. Click to enlarge.

With demand growing for even smaller power harnesses, Hitachi Cable developed the new connectors.

While most traditional connectors are configured so that a male terminal is inserted into each female terminal with a built-in spring, both male and female terminals in the newly developed compact connector are flat. This simple, novel structure allows a single spring to apply surface pressure to multiple terminals and reduces the connector volume by more than 40%, compared to previous Hitachi Cable connectors.

For example, a traditional connector for cable conductors of 15 mm2 would have volume of 300 cc. The new compact connector measures 168 cc. In addition, this lineup of connectors includes two variations—one using extending cables and one using a bus bar—allowing customers to choose the type of connection they prefer between the male connector and the electric device.

The connector also uses a structure in which spring force is applied after inserting the connector, facilitating connections and achieving high vibration resistance (181 m/s2 under the ISO 16750-3 standard) through increased spring pressure. This in turn promotes stable electrical performance, even under conditions of severe vehicle vibration.

Combining this newly developed connector with Hitachi Cable’s heat-resistant, flexible cables makes it possible to design harnesses that can be installed in narrow spaces and that are even easier to handle than previous models. The new connector will be compatible with cable conductor sizes ranging from 15 mm2 to 40 mm2.

Hitachi Cable plans to expand this area of its business while pursuing development activities to increase harness performance, thereby contributing to further advances in next-generation electric vehicles.



Could the connectors and cable weight be reduced in the same proportion? Would heat resistant hollow foam-teflon or cooling liquid filled cables work?


Eventually motor, inverter and battery will be housed together.. negating most of the cables and connectors now needed.


Doubt that the batt pack will be integrated into drive. It's too bulky, too heavy and needs to be located in safe area with emergency disconnect in the case of an accident.

The comments to this entry are closed.