Q. What is the purpose of a battery clip?

Answer

A battery clip is a cheap and easy option for safely attaching batteries to a holder. Typically, they are made out of two metal arms organized in a loop with a narrow opening at the top, into which the cells are pushed and then kept. A battery holder is a housing for a single or many batteries. Although AA and AAA batteries are the most frequent kind of batteries to use with a clip holder, these holders are also available for use with C, D, and 9V PP3 cells. This means the through-hole variant is preferable in situations when there is a scarcity of free space.