The relationship between the hydrogen content of the crystal lattice of PbO2 and the capacity of PAM is still a subject of interest. The present paper concerns the effect of the doping of β-lead dioxide on the composition of PAM gel zones and its relationship to battery performance. Differential scanning calorimetry (DSC) and thermogravimetry (TG) as well as X-ray diffraction analysis were used as techniques of investigation in this study. The results showed that the quantity of water present in the gel zones and PAM discharge capacity are mainly dependant of the nature of the dopant.