Mass adoption of Electric Vehicles (EV) will become the center of low carbon energy transition policies in transportation, requiring millions of batteries to be made available in the market during the next decade. When these batteries are considered exhausted for its EV application, they can still provide value in other less demanding uses, known as the Second Life (SL). A potential SL for EV batteries is the behind the meter space, providing benefits to prosumers and the grid. Nevertheless, the main barrier for the deployment of a SL battery market oriented to prosumers connected to the distribution system is the quantification of the economic value of those benefits and its relation with different operating conditions and tariff scenarios. This paper proposes a methodology to estimate the value of SL batteries that takes into account the degradation state at the end of the First Life (FL) and the potential operating conditions for the Second Life. A case study involving a typical residential prosumer in California is presented to illustrate the methodology.