What are "Series" & "Parallel Circuits"? Circuits consisting of just one battery and one load resistance are very simple to analyze, but they are not often found in practical applications. Usually, we find circuits where more than two components are connected together. Kidder has created a kit that will help teachers get their message across to students about the characteristics of electricity. This kit includes 2 x 70-3205-00 D cell batteries and 5 bulbs 80-3517-00.