Batteries and fuel cells are one of the most important parts in electric vehicles due to their ability to provide the propelling power. Complete characterisation of these electrochemical devices in operando conditions is therefore necessary to guide the device development and to improve the driving range and charging speed of electric vehicles. Here we show several examples of how modern, high brilliance X-ray sources can be used to collect 3D snapshots of running electrochemical devices. This helps to understand their internal functioning and the processes leading to the device degradation. Structural and chemical tomographic information of bulk materials and interfaces is obtained at all length scales, ranging from centimeters to Angstroms, with sufficient temporal resolution. Experiments in operando conditions are used to understand the internal functioning of the device and to tune the operation conditions. Our tools developed at ESRF and tailored to probe electrochemical devices are available for all users from industry and academia.