A battery module includes an insulating base, a pair of electrodes and multiple battery packs. Each electrode is installed to the insulating base and has a bridge portion and a wire connecting part exposed from the insulating base, and a pair of lugs is extended smoothly from each battery pack, and an end of at least a part of the lugs is attached to each bridge portion correspondingly. Therefore, the lug is not being twisted or deformed easily, and the battery module may have good conductive efficiency, long service life, and convenience of changing the battery pack.