With the higher penetration of intermittent renewable energy sources in the electric power grid, more flexibility is needed to cope with challenges related to stability and reliability. Consumers can be part of the solution through demand response, for example, by investing in residential batteries that can charge and discharge based on price signals (implicit flexibility) or externally controlled based on grid-related needs (explicit flexibility). In this study, we investigate the feasibility of deploying residential batteries through a case study consisting of 20 households located in south-eastern Norway. The potential annual savings from implicit flexibility are optimized based on the retail electricity price, a power-based tariff, and potential revenues by selling electricity to the grid. Real historical price and consumption data with hourly resolutions from the entire year of 2022 are used as input for the optimization, yielding a theoretical profit potential. Based on this, profitability analyses are performed. The results show that the battery investments will not reach an economic break-even point during their lifetime under today’s electricity price conditions. However, future developments in profit increase from implicit flexibility, substantial investment support, or additional revenues from emerging flexibility markets could make the investment economically attractive for a regular consumer.