A battery replacement system is configured to move a spare battery to an automatic guided vehicle. The battery replacement system includes a charging stand and a carrier. The charging stand includes a base and a plurality of supporting seat. The supporting seats are pivotably disposed on the base and configured to support the spare battery. The carrier includes a frame and a clamping component. The frame is located aside the charging stand. The clamping component is movably disposed on the frame and configured to replace a vehicle battery on the automatic guided vehicle with the spare battery.