The x-ray absorption fine structure of a technologically important MmL(5) intermetallic compound (Mm = La0.52Ce0.34Nd0.10Pr0.04, L(5) = Ni3.5Ca0.8Mn0.3Al0.4) in the form of a hydrogen storage cathode was recorded in situ in the region 5440-6290 eV using an electrochemical cell which is essentially a fully functioning alkaline battery. Significant differences were observed in the x-ray absorption near edge structure (XANES) of all of the absorption edges (La, Ce, and Nd) between the uncharged and fully charged states. In particular, a clear increase in the intensity of the La and Nd L(III)-edge resonances (due to 2p(3/2) --> 5d electronic transitions) was found upon charging the cell. This phenomenon was attributed to an increase in the density of empty d-like states near the Fermi level following hydrogen injection into the lattice. Furthermore, the behavior of the Ce L(II,III)-edges of this battery material upon charging was nearly the same as that observed for the gas phase hydrogenation of the Ce2Fe17 and Ce2Fe14B intermetallics reported in the literature.