Abstract Along with the development of connected devices and smart environments, the Internet of Things (IoT) has been receiving attention for years because of the growth in the number of devices. It enables a new breed of services and applications expected to analyze and augment captured data from IoT devices in order to create meaningful information for end‐users. Due to the limitations of computing and storage on devices, cloud computing is considered as a promising computing paradigm, which can provide elastic resources to the IoT services and applications. In this paper, we investigate the problem of IoT devices deployment in Cloud‐Fog system to provide the maximum operation time under the battery constraint of IoT devices. We formulate the problem using a Linear Programming (LP) model taking into account the characteristics of energy resources in Cloud‐Fog system as well as the IoT services‐specific requirements under two situations with and without battery constraints of the Fog Node devices. As the solution from the LP model might be too complicated for small devices, we propose a heuristic algorithm for solving the problem. The experimental results show that our proposed heuristic solution is very close to optimum solution in terms of energy efficiency.