The present application relates to a 1.5V lithium battery. The lithium battery includes a circuit assembly, a plastic frame, a wound battery core assembly, a first metal housing, a second metal housing, a first insulating seal and an insulating sheath. The wound battery core assembly is arranged in the second metal housing, the first metal housing and the second metal housing dock with each other and fixed by circumferential welding, and the circuit assembly includes a PCB, a low-voltage positive cap, a high-voltage positive connecting piece and a negative elastic piece. In the present application, the circuit assembly can stably output a low voltage of 1.5V.