In the search to find new battery technologies that will extend current Li-ion technology towards the high-energy density and stability required for extended-range electric vehicles and efficient grid energy storage, earth-abundant working metal ions are increasingly being investigated. Calcium ion batteries are of interest due to calcium’s wide accessibility and abundance in the earth’s crust, but present novel challenges, such as sluggish diffusion kinetics and lack of known suitable intercalation hosts. The replacing of Ca metal anodes with new alloy materials that can work reversibly in current electrolyte systems is one practical route towards realizing the high voltage and capacity of a calcium battery. This complements current research in conventional Li-ion batteries to replace the conventional graphite anode by Group IIIA and IV elements. In this work, research into new alloy designs in novel electrochemical systems for Ca batteries will be explored and evaluated alongside key issues and challenges towards commercial applications.