Hybrid (HEV) and pure electric (EV) vehicles are nowadays considered as the new frontier for the mobility. The claim is to solve a number of problems that are affecting the person and goods mobility, from the environmental point of view but also from the safety and the traffic congestion point of views. However, some concerns, in particular about the energy sources and availability are open questions. Hybrid architectures are seen as the transition toward the purely electric solutions. But probably a wide revolution of the mobility system has to take place, with new paradigm for different mobility types. For example, urban mobility is quite different and poses different targets with respect to the long-distance mobility. Goods delivery inside the town are suitable for different solutions with respect to highway trucks transportation. The paper, after a brief overview of the proposed architectural solutions for HEV, proposes a discussion of the advantages that can be obtained by using different paradigms. Then, some open questions related to hybrid and purely electric configurations are addressed. One of the key points is the availability of battery packs with enough energy capacity, affordable costs and at reasonable prices in relation with the vehicle missions. Therefore, present research activities are devoted to the development of optimal efficiency solutions both at subsystem and complete vehicle level. In detail, we will discuss some issues related to Battery Pack systems and Battery Management System (BMS) that have not yet reached an adequate level of robustness and reliability and need further investigations.

The accurate evaluation of the state of charge (SoC) and of the state of health (SoH) becomes straightforward to properly exploit and maximize the performance of the battery pack. In addition, mechanical and thermal design issues, that include lightweight, battery pack cooling, and safety in case of impact, are additional primary points that ask for adequate viable sustainable design solutions.