The main risk of lithium batteries is the amount of energy they can store. In extreme cases, improper use or other external factors may produce short circuits and even lead the battery to combustion. In this sense, monitoring battery systems is a simple yet effective method for keeping them in their safe range, minimising risks and ensuring proper operation. This work develops a low-cost system that remotely monitors batteries from any device with internet access. By doing so, a real-time server will monitor and store the battery system’s different parameters, as well as the status of every cell that composes it. Besides, the monitoring system will implement a control system to guarantee optimal and safe operation of the batteries, allowing battery disconnection if needed. As a main result, the development of this project offers a simple and low-cost design of a battery management system easily implemented in numerous environments where electrical energy management is done by storing energy in batteries.