It is clear that the world of transport is dominated by oil: today 55% of global demand for oil comes from the transport sector as a whole, the trend will increase over the years (60% in 2040). The increasingly critical scenario of pollutant emissions calls for the use of alternative propulsion sources. These include the use of hybrid propulsion vehicles (hevs) whose operating principle is based on batteries of various types, including lithium-ion batteries. The optimal operation of the batteries is obtained when they work in a temperature range ranging from 15 ºC to 35 ºC. Working with temperature valuesin the range of 0 ºC, the main effect is the loss of energy and power.