This is a tried-and-tested solution and many vehicle manufacturers have for a number of years been repurposing batteries from their cars.

The initial testing took years to gather reliability and performance data but commercial availability is also now well established. Since 2015/16 electric vehicle manufacturers around the world like Daimler, BMW in Europe, GM in the USA, Nissan in Japan, and BYD in China have been supplying repurposed batteries from mobility applications into a 2nd life in stationary energy storage solutions. (Source: Bloomberg New Energy Finance 2017)

Environmental benefit:

Reduce, Reuse, Recycle

Battery driven EVs are proving to be environmentally friendly in developed parts of the west and China where the majority have been adopted. They help to meet the goals of decarbonization, improvements in urban air quality and are showing lower-per-km operating. The batteries that power them present us with choices once they are removed.

EV batteries can either become hazardous electrical and electronic waste (e-waste) or continue to provide environmental benefits, through Recycling or Reuse.

By using a 2nd life battery you Reduce waste and less e-waste goes to landfills. 

By Recycling 2nd Life batteries at the end of their 2nd Life can be transformed into raw materials and shaped into new items.
By Reusing 2nd Life Lithium-ion batteries they begin an immediate useful 2nd Life producing carbon-free power for many years.
“By re-purposing EV batteries for stationary energy storage application, there is a significant potential greenhouse gas emissions reduction of 56%, or 24 tonnes of CO2, over the total 18-year lifetime of the battery” (source: Ahmadi, L.; Yip, A.; Fowler, M.; Young, S.B.; Fraser, R.A. Environmental feasibility of re-use of electric vehicle batteries. Sustain. Energy Technol. Assess., 6)

By choosing to put a battery to use during its 2nd Life you are doing your bit for the environment you, your children and grandchildren will be living in.