Conventional smart water meters use a built-in lithium battery when controlling the opening or closing of the water valve. After the lithium 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.
1. Ultra-low series equivalent resistance, the power density is more than ten times that of lithium-ion batteries, suitable for large current discharge;
2, long life, charge and discharge more than 500,000 times, is 500 times that of lithium-ion batteries, 1000 times that of nickel-metal hydride and nickel-cadmium batteries, if the super capacitor is charged and discharged 20 times a day, continuous use can reach 68 years;
3. It can be charged with large current, short charging and discharging time, simple requirements for charging circuit, no memory effect. Supercapacitor charging is the physical process of electric double layer charging and discharging or the rapid and reversible chemical process of electrode material surface. Current charging can complete the charging process in tens of seconds to several minutes, which is a real fast charging. The battery takes several hours to complete the charging, and it takes several tens of minutes to use the fast charging.
4, small size, compact shape, easy to install, save space, maintenance-free, sealable;
5, can be stored in a fully discharged state, and excessive discharge is harmful to many rechargeable batteries;
6, the use of safe, convenient, green and environmentally friendly to the environment.
1. Separate the battery from the water meter, thus eliminating the influence of battery life on the water meter and prolonging the use time of the water meter.
2. The high current discharge characteristic of the super capacitor ensures the reliability of the shutoff of the water valve. When the external dry battery is insufficient, the water valve can be shut off by the energy stored in the super capacitor.
3. Previously, the pursuit of leakage current indicators, mainly to protect the battery life, after switching to super capacitors, the leakage current indicators become unimportant. If the battery is low, the user can change it at any time. In this way, not only the circuit design is simplified, the factory inspection procedure of the product is reduced, and the cost of the product is also reduced.