With the advent of the Internet of things and the continuous improvement of biometric technology, the attendance system is developing towards diversification, networking and intelligence, and has become an important barrier for social security. At present, the Shenzhen Municipal Party committee and government use a new generation of attendance system - photon authentication system, which completes identity authentication through light, avoiding the problem that electromagnetic waves are easy to be captured and interfered. Each person's unique optical ID turns his / her door key, car key, membership card, access card, boarding pass, ticket, discount coupon, etc. into a beam of light, and realizes a fashionable, convenient and green life through smart phones. The attendance system terminal has a built-in super large capacity lithium battery, so there is no need to worry about the lack of power. It ensures the continuity of work and the reliability and safety of data processing.

The equipped lithium polymer battery (model 233035-200mah) is developed and produced by Shenzhen beiteli Battery Co., Ltd. Lithium polymer battery is one of the most widely used rechargeable batteries at present. It can be found everywhere in miniaturized devices such as mobile phones, tablet computers, power tools, backup power supplies, Bluetooth speakers, small household appliances and so on. The advantages of lithium polymer battery are as follows:

 ① high working voltage. The working voltage of lithium ion battery is 3.7V, which is three times that of nickel cadmium and nickel hydrogen batteries.

 ② Higher specific energy. The specific energy of lithium-ion battery has reached 140wh/kg, which is 3 times that of nickel cadmium battery and 1.5 times that of nickel hydrogen battery. 

③ Long cycle life. The cycle life of lithium-ion batteries has reached more than 1000 times, and can reach tens of thousands of times at low discharge depth, surpassing other secondary batteries. 

④ Small self discharge. The monthly self discharge rate of lithium-ion battery is only 6-8%, which is far lower than that of nickel cadmium battery (25 ~ 30%) and nickel hydrogen battery (30 ~ 40%). 

⑤ No memory effect. It can be charged at any time according to requirements without degrading the battery performance. 

⑥ No pollution to the environment. Lithium ion batteries are truly "green batteries" because there are no harmful substances in them.