Molex's low-voltage connector solutions for battery packs help improve safety and range for electric vehicles, saving overall manufacturing costs. 

In the development of electric vehicles, safety, range and cost have always been of great concern to consumers and the market, and thus have become the focus of continuous optimization by major car companies and supporting manufacturers. As one of the core components of electric vehicles, the battery pack includes the "battery system" and part of the "electric control system" in the three electric systems, and occupies a significant weight in the electric architecture of electric vehicles, which is the key to improve safety and range, and is also the key to reduce the cost of the whole vehicle. 

In recent years, the design of battery pack has shown the trend of high safety, light weight, compactness and high integration. Battery manufacturers and OEMs have been improving the safety and energy density of battery packs and reducing the overall cost through innovations in battery cathode materials and cell integration technology on the one hand. 

On the other hand, the industry has also put forward a series of new requirements for the electrical connection scheme in the battery pack, for example: to enhance safety considerations, the number of monitoring signals in the battery management system is increasing, and the number of bits of circuit connections required is also increased accordingly; in the cell voltage and temperature monitoring applications, FPC with its thin, light, easy to automate assembly and other advantages, gradually replace the traditional cable or PCB. At the same time, connectors such as "short-circuit-proof", "miniaturization" and other new requirements; the original discrete single-function device in the battery pack gradually evolved into a highly integrated and comprehensive equipment, so the demand for large-bit connectors is increasing; in order to improve assembly efficiency and reduce manufacturing costs, electrical connection solutions should be easy to operate by assembly personnel or for automated assembly processes. 

In the face of new market demand, Molex listened carefully to the voice of customers, in-depth understanding of the industry's pain points, for the application characteristics of the electrical connection in the battery pack, the introduction of battery pack-specific connector solutions to help customers improve product competitiveness. 

Based on the research of battery pack applications and feedback from customers in the industry, and combined with the competitive advantages of the products, Molex provides special connector solutions for the following eight typical applications in battery packs. 

Battery pack external communication interface 

The external battery pack communication interface is the interface between the battery management module (BMU) and the vehicle controller (VCU), on-board charger (OBC), etc. The BMU monitors the total current, total voltage, cell voltage, temperature, SOC (State of Charge) and SOH (State of Health) of the battery pack in real time. Health), and synchronize the information with VCU and OBC through the external communication interface of the battery pack, and execute charging and discharging actions according to the instructions of VCU and OBC. 

Connector design requirements. 

- Installation and connection method battery pack external communication connector is installed in the battery pack shell by panel mounting method, using wire-to-wire pairing method. 

- Dustproof and waterproof requirements: the battery pack is installed in the vehicle chassis, the working environment is harsh, the connector must reach IP67, IPX9K protection level. 

- The battery pack requires 16~20 bit signal pins and 4 bit power pins (12V or 24V, 5A Max.) for external communication. 

Solution one. 

MX150 12-position, 20-position panel mount wire-to-wire connector 

Solution 2. 

CMC 32-position panel-mount wire-to-wire connector 

In the battery system of buses and some small passenger cars, the battery management module (BMU) is located outside the battery pack. In such applications, the CSC inside the pack needs to receive power from the BMU through the external pack connector and upload the real-time sampled cell voltage and temperature signals to the BMU via CAN bus. 

Connector design requirements. 

- Installation and connection method The battery pack external communication connector is mounted on the battery pack shell by panel mount method, using wire-to-wire pairing method. 

- Dustproof and waterproof requirements battery pack installed in the vehicle chassis, the working environment is harsh, the connector must reach IP67, IPX9K protection level. 

- The battery pack requires a total of 5 signal pins and 2~4 power pins (12V or 24V, 5A Max.) for external communication. 

Solution. 

MX150 12-position, 20-position panel mount wire-to-wire connector 

The battery management master controller (BMU) is the core control unit of the battery pack. Internally, it communicates with slave controllers via CAN bus or daisy chain (or directly connected with cell sampling circuit) to monitor cell voltage and module temperature in real time; output relay switching signal to circuit breaker to control pack charging and discharging status; and monitor pack total voltage, total current and insulation status. Externally, BMU interacts with VCU and OBC for information and receives charging and discharging commands from VCU and OBC for the battery pack. 

Connector design requirements. 

- Small size: thin and compact design 

- Lightweight: suitable for fine diameter wire (0.13mm2 wire) 

- Safety: UL V0 flame retardant performance 

- Ergonomics: easy to assemble and prevent mis-insertion 

- Pin requirements: internal communication 16~24 bits, external communication 18~24 bits 

Solution one. 

Mini50 16-bit, 20-bit, 24-bit connectors 

Solution two. 

ConnTAK50 20-bit, 22-bit connector 

Slave to master communication interface 

Battery management slave controller is used in distributed battery management system. It collects cell voltage and temperature in real time through the cell sampling FPC, and converts the voltage and temperature information into digital signals and transmits them to the master controller of the battery management system through CAN bus or daisy chain communication protocol. 

Connector design requirements. 

- Small size: thin and compact design 

- Lightweight: suitable for fine diameter wire (0.13mm2 wire) 

- Signal pin position requirements: 3 ~ 8 bits 

- Safety: UL V0 flame retardant performance 

Solution one. 

Mini50 4-bit, 8-bit connectors 

Solution two. 

ConnTAK50 2-bit, 3-bit, 4-bit, 5-bit, 6-bit connectors 

High voltage sampling input/output interface 

The high voltage sampling module monitors the high voltage bus voltage in real time and converts the high voltage analog to digital signal and then transmits it to the battery management system main control board via CAN bus. 

Connector design requirements. 

- Small size: thin and compact design 

- Safety: UL V0 flame retardant performance 

- Lightweight: suitable for fine diameter wire (0.13mm2 wire) 

- Signal pin position requirements: input interface: 2 bits (300 ~ 700VDC high voltage sampling signal) output interface: 2 bits (CAN bus) 

Solution. 

Mini50 8-position, 2-position connector 

Circuit Breaker Interface 

The battery pack circuit breaker has multiple relays and current sensors integrated into it. The main controller of the battery management system controls the relay closure state through the switch signal to realize the transition of battery pack charging and discharging state; at the same time, the main controller reads the current sensor signal to monitor the charging and discharging current. 

Connector design requirements. 

- Small size: compact installation space 

- Signal pin position requirements: 10 ~ 12 bits, of which 

   - Relay control: 6~8 bits 

   - Current sensor: 4 bits 

- Mating method: Wire-to-wire connector 

Solution. 

HDAC64 10-position, 12-position connector 

Cell Voltage/Temperature Detection Connector 

In a battery pack, multiple individual cells are connected in a specific series-parallel manner to form a battery module. The cell monitoring circuitry samples and monitors the voltage and temperature of the individual cells in real time. The battery management system switches the working state of the pack according to the monitoring data and performs life balance control of the cells. In case of accidents such as thermal runaway of the cells, the battery management system cuts off the circuit according to the established procedure to reduce the damage and reports the fault to the whole vehicle controller in time to buy valuable escape time for the vehicle occupants. In this application, the large-bit unsealed wire-to-board connectors play a role in signal transmission, in size, in order to save as much space as possible to the cell module, miniaturized connectors are very helpful solutions. 

Connector design requirements. 

- Small size: connector height of 10mm or less 

- Anti-short circuit: connector terminal protection design to prevent accidental short circuit 

- Signal pin position requirements. 

   - 12-channel monitoring chip: 24 bits 

   - 18-channel monitoring chip: 32 bits 

- Safety: UL V0 flame retardant performance 

Solution one. 

Mini50 12-bit, 16-bit, 20-bit, 24-bit, 34-bit, 38-bit connectors 

Solution two. 

ConnTAK50 20-bit, 22-bit connectors 

As an authorized Molex distributor, Heilind can provide product service and support to the market. In addition, Heilind supplies products from many of the world's top manufacturers, covering 25 different component categories, and focuses on all market segments and all customers, constantly seeking a broad product offering to cover all markets. 

About Heilind Electronics. 

Founded in 1974, Heilind Electronics (Heilind) has global headquarters in Boston, USA and has over 40 locations in China, Singapore, USA, Brazil, Canada and Mexico. Heilind supports original equipment manufacturers and contract manufacturers in all segments of the electronics industry, supplying products from the industry's top manufacturers across 25 different component categories, with a special focus on interconnects, electromechanical products, fasteners and hardware, sensor products and more. 

Heilind operates with a strong inventory, flexible policies, responsive systems, knowledgeable technical support and unparalleled customer service. in December 2012, Heilind Electronics officially launched its Asia Pacific operations. Headquartered in Hong Kong, China, HILIND Asia Pacific has a regional distribution center and value-added service center in addition to a sales department; to date, HILIND Asia Pacific has opened 24 branch offices and 4 warehouses (Hong Kong, Shanghai, Tianjin, Qingdao, Suzhou, Shenzhen, Dongguan, Chengdu, Xiamen, Taipei, Tainan, Singapore, Malaysia, India, Thailand, Philippines, Vietnam, Indonesia Singapore, Suzhou and Taipei), we are committed to bringing the core value of distribution back to the industry.