Toyota and Mazda said on Thursday they have started field tests of Toyota’s “Sweep Energy Storage System” at Mazda’s plant in Hiroshima, using retired batteries from Toyota electric vehicles.
The trial connects Mazda’s main campus power supply system with Toyota’s unit through their respective energy management systems. Mazda said it is the only automaker in Japan operating its own power generation facilities and grid, combining conventional power with solar photovoltaic systems.
Neither company disclosed specifications of the storage system under test, including size, capacity or performance. Both confirmed only that the unit uses cells from Toyota’s electrified vehicles. The companies said the project aims to test stable and efficient charging and discharging, helping to balance fluctuations in renewable energy supply.
Mazda said the tests in Hiroshima would contribute to building a broader battery ecosystem. Toyota has prior experience with second-life battery projects, having launched a storage unit with Japanese utility Jera in 2022 using retired batteries from hybrid, plug-in hybrid, battery-electric and fuel cell vehicles.
