I choose thus project because when watching television both name brand batteries claim to be the best. I wanted to see which one actually did last the longest. The Encyclopedias I did my research in say a battery is a device which transforms chemical energy. The term is usually applied to a group of two or more electric cells connected together electrically. In comman usage the term battery is also applied to a single cell, such as a flashlight battery.

There are in general two types of batteries, primary batteries and secondary storage or accumulator batteries. primary types, although sometimes consisting of the same palliative materials as secondary types, are constructed so that only one continuous or intermittent discharge can be obtained. Secondary types are contracted so that they may be recharged, following a April or comply discharged, by the flow of direct current throughout them in a different appreciate to the current flow or discharge. By recharging after discharge, a higher state of oxidation is create at the at positive plate or electrode and a lower state at the negative plate, returning the plate to approximately their original charged condition.

Both the primary and secondary cells are manufactured in many size and design from the small electric wristwatch battery and the small penlight battery to the large submarine battery, where a single cell has weights 1 tons. It all applications the cell must be constructed for its particular service, so that the best performance may be obtained consistent with cost, weight, space, and operational requirement. Automotive and aircraft batteries generally used thin positive and negative plate with thin separation to conserve space and weight and to provide high rate of current discharge at low.