The thermodynamic description of Li containing systems is readily accessible by coulometric titrations in combination with EMF measurements. Although this method is often encountered in literature, the experimental apparatus needed is in general only poorly described. As Li and its alloys are very reactive substances, many parameters like the materials used for the electrochemical cell, cell geometry, establishment of O-2- and H2O-free atmosphere, etc. are all important factors for a successful measuring device. Therefore, an instrumental setup for coulometric titrations combined with EMF measurements is presented in detail, covering the general and the electronic setup used, as well as the structure of the electrochemical cell. The apparatus is validated with two measurements conducted in the Li-Sn system, which are further compared with literature data.