This proposal concerns the research of lithium battery pack architectures for electric recreational vehicles. These battery packs, specific to recreational vehicles, have as a particular constraint the limited space available and above all the power demand claimed for this particular type of vehicle. In addition to compactness, the modularity of the architectures sought will be a criterion to be considered, in order to make it possible to market such vehicles allowing to carry between 5 and 20 kWh of energy. The optimal cooling of such a battery pack at minimal cost and volume, as well as the establishment of its life span will also be investigated in the study. One aspect of the proposal, related to increasing the lifetime of the battery pack, will be the implementation of active cell equalisation systems. Similarly, phase change materials for cooling form one of the main elements of this proposal. This research project is therefore divided into three main scientific components: 1) development of dynamic and electrothermal models of battery packs that can be scaled over a range of 5 - 20 kWh, 2) cooling by phase change materials, 3) active cell equalisation.