Testing of battery cells is frequently performed on fairly large groups of cells at the same time. Before testing can begin, the cells must be properly connected to the test equipment. For cells in a rigid package, such as a cylindrical or prismatic cell (Fig. 1), the individual cells could be placed one at a time, each into its own cell holder, and the test technician must observe polarity when inserting the cell. Generally, a cell holder is provided by the test-equipment manufacturer; therefore, the wiring from the cell holder back to each single channel of the cell test equipment is guaranteed to be correct and without miswiring errors.
1. Cylindrical cells (upper right) have a hard case, permitting use of pins for electrical contact to the cell during test. Pouch cells (left) have metal tabs, requiring clips or grippers to make electrical contact during test.