Nickel-metal-hydride (NiMH) batteries are widespread in everyday life from small scale electronic devices to hybrid cars.The negative electrode is usually an AB5-type alloy (A=La.. and B=Ni) with CaCu5-type structure. However, in recent years, new magnesium based alloys have been developed which store larger amounts of hydrogen than conventional alloys. In order to characterize Nd0.75Mg0.25Ni3.45Al0.15 as a negative electrode for NiMH, we aim to use the new in-situ neutron diffraction cell recently developed for Polaris to monitor the structural changes at the electrode during charge/discharge in-situ and to extract detailed structural information regarding deuterium atoms by Rietveld refinement. On top of that, the effect of battery cycling rate on structural parameters will be analysed.