Modeling and simulation are useful tools to optimize and analyze the dynamic behavior of lead-acid batteries. One of the main problems is that the governing equations of lead-acid batteries are highly coupled which significantly increases the computational time of numerical methods in simulations. Using reduced order models (ROM) is one of the best ways to overcome this difficulty. In the present study, the one-dimensional electrochemical governing equations of lead-acid battery are solved using model order reduction based on proper orthogonal decomposition (POD). To show the capability of this method, the governing equations including conservation of charge in solid and liquid phases and conservation of species are solved simultaneously for a lead-acid cell during discharge, rest and charge process. The results of reduced order model including cell voltage, acid concentration and state of charge (SoC) are compared to the results of finite-volume method (FVM). The obtained numerical results show that not only the POD-based ROM of lead-acid battery significantly decreases the computational time (speed-up factor of 15) but also there is an excellent agreement with the results of previous computational fluid dynamic (CFD) models.