Battery Management System
An electric vehicle is one the most eco-friendly modes of transport. Instead of burning out precious fuel, these vehicles work with the support of Lithium-ion batteries. These batteries are considered the lifeline of EVs. In the earlier days, these were directly deployed within the vehicle, which raised many safety concerns. In order to check the safety risk and enhance the battery performance, Battery Management Systems were introduced.
What is BMS?
Battery Management System (BMS) is a technology within an Electric Vehicle that intelligently controls the battery charge and ensures safe operation, stable performance, and prolonged battery life under diverse conditions. It consistently monitors the battery pack during charge and discharge sessions and optimizes the performance by balancing the cells inside the pack, thus improving the battery life and capacity.
Functions of BMS
It shields the battery from damage, checks the battery life, and maintains it in operational condition. The fundamental functions of a BMS include battery protection, monitoring, and optimization. The BMS monitors the cell voltage and temperatures and then limits the power input and output, thus protecting it from overheating and overcharging. It communicates to isolate the battery pack from the source and load when necessary. It constantly helps in estimating the battery pack state of charge (SoC) and state of health (SoH) during charging and discharging sessions. Advanced battery management systems are capable of determining the remaining useful life (RUL) of the battery, performing cell balancing, as well as monitoring and storing historical data.
Generally, while BMS monitors the voltage, current, temperature, and life of battery cells, they are also capable of catering to other functions like checking for faults, and determining available energy and remaining useful lifetime.
Battery optimization with cell balancing enhances the battery life and capacity, thus improving the efficiency of electric vehicles. BMS comes with both centralized and modular architectures. It will have a master BMS along with various small remote units. In modular/distributed architecture, the remote units will control individual cells and they are parallelly connected to the Master. In some architectures, they are also daisy-chained in series. Individual lithium-ion battery cells come in the 3–4V range. Series connection delivers higher voltage, and parallel connection increases capacity. In case of any emergency, the connections from smaller battery modules to the BMS master will be isolated, protecting the master from damages due to high voltages.
Amphenol Automotive Grade Solutions for BMS
The accuracy, performance, and reliability of the BMS whilst maintaining safety standards are defined by the components used within the system. Amphenol offers a range of compact, flexible high performing for these power circuit designs.
With the improvements in BMS, it is essential to choose the right to interconnect solution. Amphenol provides a wide range of connector solutions for automotive battery management systems. WireLock® 1.8mm Wire-To-Board connector system is one of the newest addition to the range of automotive grade connectors and designed for use in BMS applications. These compact 1.8mm connectors address the growing demand for miniaturization in the automotive application market. These USCAR compatible connectors have very reduced mating and unmating forces and are offered in 4 different color codes, which avoid visual mismatching. TPA and CPA features ensure a secured connection, adding to the safety of the entire system.
Amphenol's Minitek MicroSpace™ are automotive wire to board connectors that are offered in a unique design to support many automotive applications including BMS. These LV214 compatible connectors are offered in 1.50mm, and 1.27mm pitch sizes in single and double row versions, with top and side latch configurations. This automotive connector is rated up to 100 mating cycles on Gold/GXT® contacts and enables a current rating of up to 4A per contact. LV214 Severity-2 compatibility makes this Wire to Board connector especially suitable for automotive applications.
The TPA ad CPA features make these connectors vibration-tolerant and have a hallmark connector locking strength of more than 75N. These automotive crimp connectors are capable of withstanding harsh environments with the design based on existing and proven design controls. The Poka-yoke polarization and keying helps to prevent visual mismatching. The compact 1.27mm connectors are suitable for advanced miniature applications.
Compact Connectors for Automotive Battery Management Systems
Amphenol also offers the latest Minitek® Multipitch Wire-to-Board connector for automotive battery management systems. The connector system is offered in single and double rows with active latching, and optional TPA and CPA features. While 1.25mm connectors have a current-carrying capacity of 1A and external cable diameter from 28AWG to 26AWG, the 1.50mm connectors come with a current-carrying capacity of 2A and cable external diameter from 24 AWG to 28 AWG. The housing with positive locking and hold down features increases the board grip force and ensures secure mating retention. These compact connectors are also known for their ability to address the growing demand for miniaturization.