Metal hydride reactors were built with porous powder metal hydride (PMH) compacts. An improved reactor built with copper coated PMH compacts of LaNi5 with a 1.27 cm diameter produced a nominal specific cooling power of 1.5 kW/kg hydride. A similar reactor, built with copper coated PMH compacts of Ca(0.4)Mm(0.6)Ni(5), showed 2.2 kW/kg hydride. Results with copper coated PMH compacts showed improved thermal conductivity. The compacts are structurally strong and prevent migration of fine metal hydride particles. Life-cycle tests were performed on the reactor with LaNi, for over 3000 cycles and the cooling power of the reactor gradually decreased by approximately 55%.