In this study the apparent activation energy of pure and multicomponent transition metal oxalate coprecipitation reactions were experimentally measured via time dependent extinction of light passing through the reaction solution. These measurements provide a quantitative descriptor of the influence of the relative transition metal composition on the nucleation and growth processes of the precipitates. The resulting crystal structures of the synthesized precursors were also determined and put into the context of the measured coprecipitation apparent activation energies, revealing that the apparent activation energy may indicate impurity or secondary phase formation before it was detectable with X-ray diffraction. This paper is the first report of using apparent activation energies to investigate battery precursor coprecipitation reactions, and these methods should be extendable to chemistry for coprecipitation of many multicomponent transition metal particles which have applications in multiple fields including energy storage materials. (C) 2019 Elsevier B.V. All rights reserved.