Battery Connectors: The Unsung Heroes of BESS Applications

By John Froustet | August 15, 2023

Battery energy storage systems have revolutionized the way we store and utilize electrical energy. With the growing need for reliable energy storage solutions, battery technology has become a pivotal player in the global energy landscape.

The rise of renewable energy sources, such as solar and wind, has presented both opportunities and challenges for power grids worldwide. As these sources are intermittent, storing excess energy during peak generation periods is essential to meet the demand during low-generation periods. Battery energy storage systems (BESS) have emerged as a promising solution for bridging this energy gap. These systems not only stabilize the grid but also enhance its overall efficiency.

Battery energy storage systems have revolutionized the way we store and utilize electrical energy. With the increasing demand for renewable energy integration and the growing need for reliable energy storage solutions, battery technology has become a pivotal player in the global energy landscape. A critical component of these systems is the battery connector, which ensures efficient power transfer and reliable connections.

These connectors are critical components that facilitate the transfer of electrical energy between the battery cells and the application. They must be designed to handle high currents, minimize power losses, and provide secure and reliable connections. Battery connectors come in various shapes and sizes, catering to different types of batteries and applications.

Renewable Energy Depends on Energy Storage

An energy transition requires support in many areas of the smart energy grid and sector coupling. Starting with energy generation, and continuing through storage and provision, it is necessary to have application-specific products in the areas of connectivity, electronics, automation, and condition monitoring, ensuring the right solution for any demanding project. Renewable energy sources are a future-oriented technology – but this energy must be stored to be used optimally.

With the use of renewable energy, it is becoming increasingly important to store it so that it can be called up when it is needed. For this purpose, there are ESS (Energy Storage Systems) which in turn consist of individual battery packs. Battery connectors are critical to connect these packs with each other.

Battery connectors provide the critical link between energy storage systems and energy collecting technologies.

Whether in smaller storage systems for home use or in large battery containers, battery connectors should cover a wide range of applications with current capacities of 100 and 120Amp in the smaller size, 150 and 200Amp in the middle size (all of which are already available). Other options should be able to have current capacity up to 350Amp. These connectors are designed to manage voltages up to 1,500 Vdc.

Features of Quality Battery Connectors

On the wiring side, there are options for conductor cross-sections from 16 mm² to 50 mm². In the near future, conductor cross-sections of 70 mm² and 95 mm² also will be available.

On the mating part, there is a busbar where the conductor can be easily connected on the device by means of a cable lug.

Battery connectors should offer several key advantages for BESS applications:

High current carrying capacity: Connectors should be engineered to handle high currents, allowing for efficient energy transfer and reduced power losses.
Robust Design: The connectors should be designed to withstand harsh environmental conditions, ensuring their reliability and longevity in demanding applications.
Easy and safe handling: Connectors should be user-friendly and feature mechanisms that prevent accidental disconnections, making maintenance and operation safer.
The contact should be made of copper alloy finished with silver and approved according to UL 4128 to warrant the best electrical contact with more than 100 operations of mechanical connection and disconnection (without load).

Color coding is important, such as color coding for positive connection (orange) and negative connection (black) on both the connector and the mated busbar connection. This creates a key visual to the user of where connections need to be made.

Both sides of the connectors are key coded to alleviate the possibility of user error or plugging the wrong side into the mating busbar connection. This special key coding allows the connectors to be plugged in literally any orientation, avoiding unnecessary mechanical stress in the cable.

A locking mechanism fastens the plug and the socket. This mechanism is a fundamental safety feature considering the high quantity of energy managed by this connector and the risk of an arc fault with catastrophic consequences if one accidental disconnection happens under load. Additionally, a little movement from the connector could reduce the contact area and create a hot spot which could lead to a fire in the BESS. This locking feature prevents both conditions and it can be disconnected in a very practical way through the push of a button.

Weidmuller’s connector solutions serve a diverse array of battery and energy storage applications.

Battery energy storage systems are pivotal in modern energy management, facilitating the integration of renewable energy sources and enhancing grid stability. Battery connectors are essential components in these systems, ensuring efficient power transfer and dependable connections.

As the world moves towards a more sustainable energy future, battery energy storage systems, along with advanced battery connectors, will continue to play an instrumental role in shaping the way we harness and utilize electrical energy. Continued advancements in energy storage systems and battery connector technologies hold the promise of unlocking the full potential of renewable energy and accelerating the world’s journey towards a cleaner, greener, and more sustainable energy ecosystem.

Learn more about Weidmuller’s solutions and products for Energy Storage Systems.