October 2019 - High-concentration aqueous electrolytes have shown promise as candidates for a safer battery system. Ionic conductivity is a key property required in high performing electrolytes; the Advanced Electrolyte Model (AEM) has previously shown great accuracy in predicting ionic conductivity in highly-concentrated non-aqueous electrolytes. This work provides extensive experimental data for mixed and highly concentrated aqueous electrolyte systems, rapidly generated via a robotic electrolyte testing apparatus. These data demonstrate exceptional accuracy from AEM in predicting conductivity in aqueous systems, with the accuracy being maintained even in highly-concentrated and mixed-salt regimes. Sensitivity of the model to choice of a key solvation parameter, reference ligand-ion length, is explored. Walden analysis using transport properties predicted by the model for aqueous salts and mixed salt systems is also included, as well as predictions of cation transference number for salts and mixed salts. These predictions are explained in terms of AEM's underlying chemical physics modeling.