Toyota installs Sweep energy storage at Mazda’s Hiroshima plant using retired EV batteries.
System reuses entire battery packs, integrating inverters and handling varied chemistries.
Currently in testing phase, targeting production-line energy buffering via solar power integration.
Toyota has installed a second-life energy storage system using retired electric and hybrid vehicle batteries at Mazda’s car factory in Hiroshima, Japan. The system, called Sweep Energy Storage, is designed as a power buffer between the facility’s solar generation and its production line.
The modular setup reuses entire battery packs from out-of-service vehicles, including their original inverters, reducing the need for external control hardware. Unlike conventional storage systems, it integrates packs of varying chemistries, capacities, and states of health—ranging from lithium-ion to nickel-metal-hydride and lead-acid units.
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Currently in a testing phase, the Sweep system at Mazda’s plant is being evaluated for stability in charge-discharge cycles. The goal is to determine whether the system can be reliably scaled to support production power requirements.
Toyota developed the Sweep system in 2022 with Jera, Japan’s largest power generation company. Jera’s version delivered 485 kilowatts of output and stored up to 1,260 kilowatt-hours of energy. Central to the system is Toyota’s proprietary control device, which manages energy discharge by switching flow through series-connected cells, allowing individual batteries to be bypassed as needed.
The system offers an alternative to recycling or landfilling older EV batteries, particularly from vehicles damaged in collisions. By repurposing these units for storage, Toyota is exploring extended lifecycle applications for the units and within the automotive and industrial sectors.
Source: Insideevs
