Open this lesson plan by reading together about primary and secondary batteries (such as nickel-cadmium cells), problems they can cause in the environment, and how humans can minimize the damage. Afterward, little ones examine a collection of batteries and identify what type each one is. They list all of the battery-operated devices in the classroom and answer an array of true-false questions about safe handling of batteries. Instructions are provided for initiating a battery recycling program as well as for surveying students' homes for the number and types of batteries they use.