Why does the button battery last long?

Why is the button battery durable? Button battery can be used for more than one year, or even longer. The reason is simple. It is not because the button battery has too much power, but because the device powered by it consumes too little power.

Now the most common place to use button batteries is the memory function of watches and electrical appliances. For example, the time and date circuits of cameras and cameras do not use the power of the main power supply, but use button batteries to supply power independently. This is based on two reasons: one is to prevent the interruption of time recording when the main power supply is exhausted or powered off, and the other is that the memory power consumption is very small, so it is possible to use a small battery to supply power independently.

Generally, the time circuit of a camera consumes less than two microamps of current, which is only 1/10000 of the current of a low-power LED lamp bead. Such a small current has almost the same service life as some batteries.

Another use is electronic watches. Due to the mechanical action, the current of the electronic watch is much higher than hundreds of microamps. However, the electronic watch belongs to the pulse type intermittent electricity use. Only at the moment when the second hand beats, there is a large current. In other periods, there is almost no current. One of the characteristics of batteries is that the intermittent discharge life is much longer than the continuous use life. Because the battery discharge is a chemical reaction process, the intermittent discharge can make the battery have a recovery process, thus extending the service life.