This paper presents the analysis and results developed during a master thesis internship with the Swedish company Enerpoly. The objective of the thesis was to assess and establish a grading and quality control system for the zinc-ion battery cells manufactured by the company. For this purpose, several pouch cells were assembled and submitted to formation cycles, self-discharge, and cycle life tests. While from an initial study, analysing and relating the formation cycle parameters, it was concluded that 2 formation cycles are sufficient for a stable operation of the cell, no reliable outcomes were reached from the self-discharge tests due to a problem in the cycler.