Mobile payment is a service mode that allows users to use their mobile terminals to make accounting payment for the consumed goods or services. Units or individuals directly or indirectly send payment instructions to banks and financial institutions through mobile devices, Internet or proximity sensors to generate monetary payment and fund transfer behavior, so as to realize the function of mobile payment. Mobile payment integrates terminal equipment, Internet, application providers and financial institutions to provide users with financial services such as monetary payment and payment. The mobile payment terminal uses high-performance lithium battery pack for power supply to meet the continuous, efficient and stable operation of the product.
1. Design requirements for lithium battery of mobile payment terminal:
According to the customer's requirements and product specifications, design the battery pack matching with the host, and integrate the lithium battery and safety protection performance into the solution. In the whole design process, to achieve the most perfect integration with the host as the direction, to ensure the safety of the battery, battery pack and the whole system as the premise, to meet the corresponding design regulations and certification regulations as the preferred consideration. At the same time, in order to ensure the safety and reliability of the lithium battery, multi-layer protection should be taken inside the battery pack to prevent the lithium battery from being damaged due to overcharge, over discharge or short circuit.
1) Design requirements of lithium battery pack model: 402060-1s1p / 450mah / 3.7V.
2) Circuit design requirements:
• Single section overcharge protection voltage: 4.28 ± 0.25V
• Single section overcharge recovery voltage: 4.08 ± 0.50v
• Single section over discharge protection voltage: 3.00 ± 0.08v
• Recovery voltage of single section over discharge: 3.00 ± 0.08v
• Over current protection value of combined battery (10ms): 1.5 ~ 3.5A
• Over temperature protection value of combined battery (recoverable): 70 ± 5 ℃
• The finished battery also has short circuit and reverse charge protection.
3) Battery cycle life design requirements: 300 ~ 500 times (national standard for charging and discharging)
4) Battery size design requirements: refer to the host shell
2. Mobile payment terminal lithium battery design scheme:
1) Protection board (PCM): it is mainly a protection circuit designed for rechargeable lithium battery pack. Due to the chemical characteristics of lithium battery itself, it needs to provide intelligent power calculation, overcharge, over discharge, short circuit, overcurrent and other protection functions to avoid burning, explosion and other hazards.
2) Protection IC (Protection IC): the main protection function chip of the design scheme, which can monitor the overcharge, over discharge, over current, short circuit and other functions of the cell online and constantly, so that the cell can work in a safe, stable and efficient range.
3) Temperature switch: mainly designed for temperature protection function. When the temperature of the battery itself reaches 70 ± 5 ℃ due to other abnormal problems, the temperature switch will act for temperature protection.
4) Polymer Li ion cell: 402060p / 450mah / 3.7V Li polymer cell.
5) Field effect transistor (MOSFET): MOSFET, in the protection circuit to play a switching role, always make the voltage at both ends of the load will not rise or fall, to ensure voltage stability.
6) Battery package: PVC heat shrinkable