A high-current (up to 100 A), short-pulse (1-µs duration) electrolysis technique is presented that permits high loading (D/Pd up to 1.2) of deuterium in palladium cathodes. Several different cold-worked palladium plates were used as cathodes, and some underwent surface treatments (oxidation or addition of intermetallic compounds). The surface-treated plates showed atypical deuterium absorption dynamics, and the D/Pd loading ratio exceeded 1. Moreover, during initial loading, these cathodes showed anomalous excess heat (up to 80%) far greater than the absorption enthalpy. The pure palladium surface plates did not show this effect.