A new type of lead acid battery, the lead air battery, designed by altering the lead dioxide electrode to the air electrode, is put forward in this research. Two models are developed for simulating the activation polarization and time dependent processes respectively. The models illustrate the performance of the lead air battery, with respect to the effects of air electrode activity, electrode area ratio, Pb electrode thickness and current rate. The specific energy density of the lead air battery is identified to be about 42.9–49.7 Wh kg−1 at the current rate range of 2.0–0.1 C, with literature parameter values. Moreover, the cycle energy efficiency of the lead air battery is about 65.9–73.5% and the specific capacity is about 35.8 Ah kg−1. This research proposes lead air battery a feasible type of next generation of lead acid batteries, with advice on its future development.