The curriculum of our school consists of a separate class of theoretical and experimental classes. As a result, it is difficult to experience experiments related to class contents and it is necessary to carry out experiments related to class contents separately from experiment classes. However, experiments that do not overlap with experimental classes should be conducted. Under the theme of chemical cell and electrolysis, students conducted an open experiment to construct a battery by selecting from the given conditions, giving students an opportunity to learn the practical skills required for the experiment and compare the experimental results according to various conditions. Lesson Results The students showed interesting reactions such as constructing and comparing chemical cells under various conditions, not the conditions presented in the textbooks, or constructing chemical cells that exceed the limitations of the given conditions by changing the substances with additional chemical reactions.