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Understanding reconfigurable EV battery packs

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Reconfigurable battery packs dynamically adjust internal connections, voltage, current distribution, and power output.  Unlike conventional fixed packs, they isolate faulty cells, balance power loads, and respond to dynamic energy demands. These capabilities are increasingly important for electric vehicles (EVs), as well as renewable energy storage and smart grid infrastructure.

This article explores the key functions of reconfigurable EV battery packs, focusing on technologies such as active switching, selective balancing, and dynamic load management. It also reviews key barriers to large-scale adoption and outlines emerging applications beyond EVs, including grid-scale storage and renewable integration.

Key functionality

As shown in Figure 1, reconfigurable battery packs transform passive cell stacks into adaptive systems by adjusting series–parallel connections in real time.

Figure 1. Reconfigurable battery systems use controllable switches, embedded controllers, and modular pack topologies to manage current flow and optimize performance. (Image: UNL Digital Commons)

These packs belong to a broader class of reconfigurable battery systems (RBS), which leverage power-electronic switches, intelligent battery management systems (BMS), and control algorithms to determine when and how to rewire the pack across hardware topologies.

Core capabilities of reconfigurable battery packs include:

  • Providing fault tolerance by isolating compromised cells or modules without disabling the entire pack.
  • Balancing loads by redistributing current to equalize the state of charge (SoC), voltage, and temperature across cells.
  • Reconfiguring in real time by switching between series and parallel paths based on dynamic power and energy demands.
  • Supporting potential hybrid chemistries by coordinating semi-solid, iron-air, and lithium-ion sub-packs within a unified system.
  • Enabling rapid modular swapping with designs that facilitate sub-five-minute pack replacements.

These capabilities support extended range, longer cycle life, faster charging, and improved reliability.

Active switching, balancing, and load management

Reconfigurable battery packs leverage several core technologies to support real-time adaptation, ensure safety, and extend operational life.

Active cell switching uses solid-state relays or MOSFET H-bridges to bypass or reconnect individual cells or modules. This allows the BMS to reroute current around aging or failed units, maintain pack continuity, and adjust voltage and configuration based on load conditions.

As shown in Figure 2, active balancing complements active cell switching by equalizing the SoC across the pack.

Figure 2. Active balancing systems redistribute charge between cells to equalize state of charge (SoC) and reduce energy loss. (Image: Monolithic Power)

Instead of dissipating excess energy as heat, it uses bidirectional converters to transfer charge from higher to lower-capacity cells. Algorithms identify and prioritize imbalances to reduce switching, thermal cycling, and long-term degradation.

Dynamic load management coordinates these functions. Real-time telemetry enables the BMS to anticipate load transients and reconfigure pack topology to maintain even current distribution, safe voltage and temperature ranges, and efficient operation under variable demand.

Real-world EV applications

An increasing number of commercial and pre-commercial programs demonstrate that reconfigurable battery technology has moved beyond the lab. Although fully reconfigurable systems remain limited, several manufacturers are fielding systems with reconfigurable elements. Examples include:  

  • CATL (China) is deploying over 1,000 battery-swapping stations that use modular, reconfigurable packs. Each station replaces a depleted module in minutes; onboard switches then adjust series–parallel paths to match the vehicle’s voltage and current while isolating weak cells and balancing loads.
  • BYD (China) incorporates advanced zoning and management features in its 1,000-V Blade battery. Thermally independent regions activate cells based on temperature, SoC, and performance — enabling five-minute, 400-km fast charging while reducing lithium-plating risk and supporting hybrid chemistries.
  • Pulsetrain GmbH (Germany) integrates an AI-based powertrain that evaluates cell health and load forecasts every few milliseconds, rewiring internal connections to reduce current peaks and temperature gradients. Early field data indicate an 80% increase in usable cycle life for high-duty vehicles such as electric buses and delivery vans.

Scaling: challenges and opportunities

Reconfigurable battery packs offer EV manufacturers key operational advantages, such as extended range, longer cycle life, faster charging, and improved reliability. Large-scale adoption, however, remains limited by several technical and economic constraints.

Cost presents one of the most immediate barriers. Modular pack structures, power-electronic switching, and intelligent BMS increase system complexity and raise the bill of materials (BOM). These requirements also introduce integration challenges, especially in space- and cost-constrained automotive and grid environments.

The lack of standardization creates another obstacle. Without universal interface protocols and compatible hardware formats, interoperability across manufacturers remains limited. This fragmentation slows adoption in multi-vendor ecosystems, restricts design flexibility, and complicates long-term maintenance.

Thermal management and safety also demand more advanced strategies than conventional battery systems, as real-time reconfiguration introduces additional failure modes and control layers.

AI, adaptive control, and advanced materials

Researchers are developing AI and machine learning–based methods to optimize performance and extend the operational life of reconfigurable battery packs. For example, a team at Marquette University recently demonstrated ML algorithms that dynamically reconfigure the pack topology to correct the SoC imbalance.

Using a network of controllable switches, the system adjusts cell connections to improve SoC uniformity and extend runtime. The framework combines extended Kalman filtering (EKF) with high-fidelity cell models to optimize balancing accuracy under varied load conditions.

Similar work at Penn State University, supported by ARPA-E, focuses on adaptive packs that retire aging cells, redistribute current, and flag units for replacement. This strategy could reduce overdesign in new packs — lowering cost and weight without compromising long-term performance.

Advances in materials and pack architecture also support scalability. Solid-state and semi-solid chemistries benefit from designs that isolate or group cells based on thermal or mechanical limits. High-performance electrodes, such as silicon anodes and high-nickel cathodes, increase energy density, while 3D pack structures optimize heat dissipation and charging efficiency.

Grid-scale applications and renewable integration

Valued at $8.27 billion in 2024, analysts project the global RBS market will grow at a CAGR of 15.29%, reaching $34.29 billion by 2034. Demand for adaptable, scalable energy storage fuels this growth across EVs, renewable infrastructure, and smart energy management systems. Key players developing reconfigurable battery technologies include Tesla, Panasonic, LG Chem, and QuantumScape.

Beyond EVs, smart grid and renewable energy storage operators increasingly deploy battery systems with reconfigurable capabilities. These systems offer the same dynamic capabilities, supporting long-duration storage, load balancing, and hybrid chemistries at scale.

As shown in Figure 3, Form Energy’s iron-air battery leverages a modular, reconfigurable architecture to deliver 100-hour backup power for utility-scale applications. The system reduces maintenance, accommodates mixed chemistries, and performs reliably under variable load profiles typical of wind and solar generation.

Figure 3. Form Energy’s iron-air battery, designed to serve inter-day periods, delivers low-cost, clean electricity when and where it’s needed. (Image: Form Energy)

In China, WeLion has deployed a 200 MWh semi-solid-state array built on reconfigurable blocks. These packs dynamically shift active regions in response to grid demand, enabling peak shaving and extended discharge.

Summary

Reconfigurable EV battery packs dynamically adjust internal connections to meet real-time power demands, isolate faults, and extend both range and service life. They integrate active switching, selective balancing, and dynamic load management. Advances in AI and materials continue to accelerate adoption across EV, utility, and renewable energy sectors.

References

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