Mousa reported density measurements for the discharged negative electrolyte for varying total vanadium concentration, sulphates concentration and temperature. Later, Rahman et al. measured the density of the positive electrolyte at 5 M vanadium concentration in 8 M sulphates concentration. Xu et al. investigated the density and thermal expansion coefficient of VOSO 4 . Skyllas et al. reported density data for both electrolytes, using 2 M vanadium concentrations in 5 M total sulphates for varying State of Charge (SoC) and temperature. However, they did not give any details regarding the experimental procedure nor provided error estimations. More recently, Ressel et al. measured the density of the negative electrolyte as a function of SoC obtaining results that were consistent with those of Skyllas et al. . Except for these two works, prior studies lack information regarding the variation of density with the SoC, a crucial parameter intrinsic to battery operation. Furthermore, a recent study by the authors has provided experimental evidence supporting previous density measurements of the negolyte, but suggesting potential overestimations in the density variations of the posolyte .