Everyone likes electric cars for how friendly they are on the environment. They may not be perfect but they don’t contribute to air pollution or airborne carbon accretion, and they help lighten dependence on oil and foreign oil-producing nations.

Ever wonder where used electric car batteries go when they die? Turns out that the question of how to recycle these spent batteries is a lingering issue within the industry.

Mitsubishi has teamed up with several other companies, including Forsee Power and PSA Peugeot Citroën, to investigate sustainable ways to convert used lithium-ion batteries to stationary energy storage units. For the project, Mitsubishi will provide used batteries taken from the Outlander and i-MiEV models.

According to Mitsubishi, “The purpose of the project is to demonstrate efficient and economically feasible energy management practices based on the optimization of electricity storage, charging and generation technology with respect to existing demand.”

If the research proves successful, the companies will work on a business model that would allow them to repackage and sell the Mitsubishi used batteries.