Conventional smart water meters use a built-in lithium ion ultracapacitor battery when controlling the opening or closing of the water valve. After the lithium water meter battery has been used for a certain period of time, it cannot supply energy to the control circuit and has to replace the battery. It is a cumbersome thing for the manufacturer to replace the battery or water meter for the user.More dangerously, the situation of insufficient battery power is random. If the battery is not accurately and timely detected, the water valve will not be reliably shut down, resulting in the inability to bill. This is a fatal shortcoming of a smart meter with a lithium battery inside, which directly affects its promotion and use.

At present, the use of supercapacitors instead of lithium batteries for smart water meters is a very popular choice. A supercapacitor is a passive device that is interposed between a battery and a common capacitor. It has a large current and fast charge and discharge characteristics of the capacitor. It also has the energy storage characteristics of the battery and has a long service life.

Supercapacitors are compared to batteries and have the following distinct features:

1. Ultra-low series equivalent resistance, the power density is more than ten times that of lithium-ion batteries, suitable for large current discharge;