Lithium‐ion battery (LIB) cells of the 18650 format are built in‐house with different amounts of an electrolyte. After wetting and prior to subsequent formation, the cells are opened. The electrolyte is regained by centrifuging the entire jelly roll and quantified by a gas chromatography‐flame ionization detector (GC‐FID) and inductively coupled plasma‐optical emission spectroscopy (ICP‐OES). The influence of a filling protocol applying cycles with over‐ and reduced pressure is examined with a focus on the electrolyte composition. No significant difference is found in the ratio of linear (LC) to cyclic carbonates (CCs). Furthermore, extraction by centrifugation is investigated in different scenarios by simulating almost “dry” cells to minimize alterations during the sample preparation. The quantification of these electrolytes indicates a slightly reduced amount of LC in the sample.