We are studying the impact of humidity of micro solid-state Li-ion batteries. In order to identify the impact of humidity on the electrochemical properties in particular to figure out where the degradation takes place (bulk, grain boundaries, or interface) a self-constructed electrochemical test-station is used. The device enables the control of humidity, temperature, flow rate and enables simultaneous battery tests. Therefore the degradation of the batteries (also in operation) in different defined environments can be track very accurately. A different approach to study the degradation of materials in humidity is the use of single-crystal X-ray diffraction over a long period of time to track the Li and H exchange rate. The observed change in the H content over time together with the penetration depth of X-rays enables the estimation of a diffusion coefficient.