Photovoltaic generation, due to its decreasing cost and versatility, has seen a growing utilization in residential buildings. However, the mismatch between the demand and the photovoltaic generation profiles leads to high power flows between the household and the grid. The appearance of tariffs that foster the self-consumption and penalize the injection of energy into the electrical grid increases the need to provide cost-effective solutions to enable the matching between electric generation and consumption. Used EV batteries are unsuitable for vehicles, but can be used in secondary applications, such as residential PV energy storage. This paper presents a technical and economic assessment of the reuse of batteries from electric vehicles as a storage system for the residential sector by analysing the cost, the remaining capacity and the lifetime for second applications through the implementation of a degradation model in MATLAB-Simulink. A case study is presented for an average Southern Europe residential building with a photovoltaic system that generates enough energy to ensure the average consumption needs.