They are alkaline which means they have double the energy density of rechargeable and primary batteries. Besides a longer shelf life they also have a longer life span so you won#t need to replace them as often. They also function at very low temperatures. AAA batteries are made with an alkaline electrolyte of potassium oxide instead of chloride or zinc which are both acidic components. Most suitable for applications where the current being used is normally low and do not require a lot of power during their use like remote controls or radios. Batteries should not be kept in devices that are not used for a long time because they can leak and thus completely ruin the device itself. Alkaline types are also bulkier than other lithium batteries which can give much higher energy. AAA batteries have the exact same amount of voltage as AA but the difference lies in how these batteries deliver the voltage. AAA is noticeable shorter than an AA.