Today, cell phones have become, for more and more users in a constant companion linked to photos, music, video, connection with loved ones and / or business, which is difficult to be separated, sometimes it seems like a string umbilical to the globalized world, however, the batteries have not kept pace with that so have the number of applications and the degree of dependence that we keep to these mobile devices interact, making it useful to pay attention to best practices efficient use of portable energy storage. With regard to maintaining the life of the batteries running longer, there are two separate aspects that relate to one another worthy of consideration, such as extending the time comes loads and how to prolong the overall battery life. In today’s market, there are three types of technologies for cellular phone batteries, these are: Lithium-ion, Nickel-Metal Hydride (NiMH) and Nickel-Cadmium (NiCD). The batteries Lithium-ion technology are highly recommended for use in cellular telephones be lighter and have an improved performance compared to other types. They are generally 30% lighter and have 20% better performance than a NiMH battery of a classification similar mAh (mAh is an abbreviation for milli-ampere hours, which represent units of electric charge in the case of battery voltage similar higher mAh value indicates that the battery has a better load capacity and operation of equipment allowing for a longer time before needing recharging) Another important advantage of Li-ion batteries is that they are susceptible to present the “Effect memory “which reduces the capacity of a battery and will be discussed later.