Several high-power lead–acid batteries have been developed for automotive applications. A computer-aided optimization (CAO) technique has been used to obtain a low-resistance grid design. Unlike conventional computer simulation, the CAO technique does not require an unduly large number of designs to yield a good result. After introducing a pair of differential equations that are expected to be valid for the optimized design, the grid thickness is optimized by solving the boundary value problem of coupled differential equations. When applied for the grids of JIS B-size batteries, this technique reduces the potential drop of electrical resistance in a electrode by 11–14%.