Chemical energy storage systems present several beneficial applications in electrical systems without the need to adapt the existing infrastructure; however, the costs of new batteries impede large scale deployment. This paper presents the design, construction and testing of a battery for stationary energy storage made from a heterogeneous pool second use lithium ion cells recovered from dead laptop batteries. The design and construction of the battery consider the characteristics of the secondhand cell to be used. Consequently, several design constraints had been taken into consideration as well as the current state of the cells to be reused. Then the battery was subject to two different tests: Simulating real life conditions over 3 months and diagnosing the new state of the cells. Both tests look to further understand the batterie's behavior and determine its viability for stationary energy storage applications. For this purpose, an automatic test bench for the battery was built the device gathers data via an array temperature, voltage and current sensors. The results from the tests show that the battery has potential for stationary energy storage applications, however, more data is needed to have a better understanding of the evolution of the battery over time.