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Connectors for EV and PHEV Battery Systems

In recent years, electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) have become increasingly popular in the automotive sector. These new vehicle models require strong battery management systems (BMS) to monitor the conditions of battery cells, in order to bring out full potential of the battery component. JAE offers a wide variety of connectors required for BMS applications. Below you can find a full lineup of our BMS connector solutions.

Trends in EV/PHEV Market and Connectors for Battery Systems

The demand for electric vehicles (EV) and plug-in hybrid vehicles (PHEV) has been increasing rapidly around the world in response to stricter environmental regulations to prevent air pollution. EV/PHEV are equipped with a large number of battery cells, and in order to maximize battery performance, a battery management system (BMS) is essential to constantly monitor the status of the battery cells. There are various requirements on the connectors used in BMS, such as smaller size and lower height. JAE offers a wide variety of connectors that meet these requirements.
The following sections describe examples of BMS connector use cases and the individual features of each connector solution.

electronic vehicle structure

Use Case Example of Connectors for Battery Systems

BMS structure

The battery unit installed in the EV and PHEV consists of many electronics including battery modules and a battery monitoring system that monitors the status of battery cells. JAE has developed a wide range of automotive connectors to be used in connecting the components within each module.
For the connectors on the battery module, it is required to have multiple key options to prevent a mating error during installation. There is also a lower height requirement due to the limited space. JAE has developed the automotive connectors to meet those requirements, with a good track record in their adoptions.
The following sections describe the product features of the connectors used in battery systems.

Automotive Connector
Catalog Download

Connector Lineup for Battery Systems

  MX34 Series MX84B Series MX77 Series
Terminal Size (pin width) 0.64 mm 0.4 mm
Mating Area Pitch 2.2 mm Signal:1.8 mm, Power:2.1 mm
Outline Size
40-Conductor Socket Housing
Thickness Dimension 21.3 mm MX77A:13.5 mm
MX77D:9.5 mm
Width Dimension 47.1 mm 46.9 mm
Depth Dimension 15.2 mm 17.0 mm
Insulator Flammability Rating Pin side SMT type : UL94 V-0
Others : UL94 HB
UL94 V-0 Pin side : UL94 V-0
Socket side : UL94 HB
Socket Side - Supporting cable connections, the contact is a box type resistant to the external force, and the connection is resistant to twisting. Two-piece spring structure has a proven track record.
- Preset retainer is reliable for detecting half insertion of contacts during harness assembly
- A bridge at the lock section provides protection on the external load, ensuring higher safety during operation. - MX77A has a bridge structure at the lock section to provide protection on the external load, similar to MX34/MX84B.
- MX77D achieves a further reduction in height by eliminating the bridging structure, while securing reduction in cable entrainment at the lock section.
Pin Side Wide range of variations
- Right angle DIP, SMT type
- Straight DIP, SMT type
- Relay type
- Right angle DIP type
- Relay type
- SMT type with right angle
(with leg to increase strength on the board mounting)
Number of Positions 3~40 7~40 4~40

Automotive Connector
Catalog Download

MX34 Series

BMS connector mx34

- 0.64mm standard tab size products meet various requirements for automotive applications, resulting in numerous achievements in the market.
- A broad selection available on the pin side with different connecting form factors.
- Evaluation tests are conducted in accordance with USCAR2 standards.

List of MX34

MX84B Series

BMS connector mx84

- UL94 V-0 materials, with excellent flame retardancy, are used for the insulator components to meet the requirement for higher safety.
- Structure and dimensions are the same as the MX34 series with a proven track record in the automotive market.
- Two types of pin connectors are available: a right angle DIP type for board connection, and a cable relay connection type.
- Evaluation tests are conducted in accordance with LV214 standards.

List of MX84B

MX77 Series

BMS connector mx77

- Series with low profile specifications adopting 0.4mm pin size in response to increasing space saving needs.
- For the cable-connecting socket, a thinner MX77D is available in addition to the standard-type (MX77A).
- MX77D allows both AVSS 0.3mm2 and ISO (Thin wall) 0.35mm2 cablings to be applied to all cavities (MX77A applies only at both ends).
- Circuit board connection type on the pin side, with the right angle SMT specification that supports automatic mounting.
- Evaluation tests are conducted in accordance with USCAR2 standards.

List of MX77

Catalog Download of In-vehicle Connector

Compact Connector


Connector Solutions for Automotive

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