A battery includes a casing, a battery pack, and at least two electrical connecting assemblies. The casing includes an inner space and plural contact planes. Vertical directions of the contact planes are different. The battery pack includes a battery cell disposed in the inner space, and the battery cell includes a positive and a negative electrodes. The electrical connecting assemblies are electrically connected to the positive electrode and the negative electrode respectively, so as to transmit power between the battery pack and an electronic device. The electrical connecting assembly electrically connected to the positive electrode is arranged on at least two of the contact planes, and the electrical connecting assembly electrically connected to the negative electrode is arranged on at least two of the contact planes. If power supply in one certain direction is interrupted, the battery transmits power in the other directions, thereby avoiding power supply from being interrupted.