The reason for the use of carbon batteries: for clocks and watches, the movement of the clock only needs a small current to cope with, using alkaline batteries or rechargeable batteries will cause damage to the movement, resulting in inaccurate travel time, and even burn the movement, affecting the service life. Therefore, it is better to use carbon batteries. However, due to its chemical characteristics, carbon batteries may leak after the power is exhausted, so it is necessary to choose high-quality carbon batteries. Alkaline battery time is too long, the internal will flow out of some corrosive liquid, these liquids if the flow into the camera, it is very easy to cause damage to the components. Alkaline batteries are not impossible to use, but to choose a low current alkaline battery below 500 mA, otherwise the watch movement is easy to be damaged by high current.