常用的电池盒,多为装两节和四节电池的。装一节和三节电池的电池盒较为少见。我们做电子实验时,需要各种电压,并且使用电池的用电器电压要求也不同。另外,普通的电池盒只能专用,不能通用……如果有一种能根据需要改变电压,需要几节电池就装几节电池,并且能装不同型号电池的电池 Commonly used battery boxes are mostly equipped with two and four batteries. Battery boxes with one and three batteries are rare. When we do electronic experiments, we need various voltages, and the voltage requirements of the consumers using the battery are also different. In addition, an ordinary battery box can only be used for exclusive use, and cannot be used universally. If there is a way to change the voltage according to need, several batteries are required to hold a few batteries, and batteries of different battery types can be installed.