This study analyzed preference and satisfaction according to the weight and size of products in order to understand how the size-weight illusion (SWI) occurs in affect. The perceived weight of an object has long been a topic of interest in the field of experimental psychology. Perceived weight is known to be affected not only by the weight of the object, but also by its size, color, and material. A total of 54 participants took part in the experiment. Ten electronic mobile batteries were prepared by combining two sizes and five weight levels. Participants were asked to rate the perceived weight of the batteries by the modulus method and evaluate the preference and the satisfaction of the weight by using the semantic differential (SD) scale of 11 points. The results showed that SWI occurred in terms of the perceived weight of cookies boxes like previous studies, however, SWI appeared only partially in affect. The preference and satisfaction did not increase after a certain weight, and the limit of weight were different according to the size of batteries. This results can be referred to determine the weight and size of a product for affective design and especially utilized for the package design of electronic mobile batteries.