I. Project Background of Smart Door Lock and Doorbell Power Supply Equipment
   With the rapid development of the smart home market driven by Internet of Things and artificial intelligence technologies. Consumers' demands for the intelligence, convenience and security of smart home products are constantly increasing. Smart door locks and doorbells, as key components of smart home systems, not only offer convenient door opening and visitor management but also can be integrated with other devices to create a smart, comfortable and safe living environment. Market data shows that the scale of the smart home market continues to expand, and the market share of smart door locks and doorbells has increased, creating market space for lithium battery applications.
   Traditional smart door locks and doorbells are mostly powered by dry batteries, but the capacity of dry batteries is limited and they need to be replaced frequently. Especially for smart door locks with rich functions, the battery life of dry batteries is insufficient. Frequent replacement of dry batteries is both inconvenient and costly, and improper handling can pollute the environment. The performance improvement promotes the wide application of lithium batteries in smart door locks and doorbells. Modern users have raised their demands for the safety and user experience of home products. As the first line of defense for home security, the stability and reliability of smart door locks and doorbells are of vital importance.
   The application of new energy lithium batteries provides stable power support, ensuring the normal operation of equipment and enhancing safety. The long battery life and rechargeable features enhance user experience, allowing users to enjoy a convenient and comfortable smart home life. This solution is designed to meet the application requirements of lithium batteries in intercom communication and shared transmission equipment projects, ensuring that lithium batteries provide safe, efficient and customized power solutions for their devices.

II. Analysis of Equipment Demand Characteristics
1. Equipment application characteristics
▲ Equipment type: Real-time security guarantee for places such as homes, schools, hospitals, and government agencies.
▲ Working environment: Temperature range, -20℃ to +70℃, high vibration, etc.
▲ Power demand: Large continuous/peak power, long battery life, and the voltage platform generally adopts high-voltage platforms such as 3.7V or 7.4V.

2. Core requirements for lithium batteries
▲ High safety: Meets the explosion-proof, shock-proof and waterproof requirements of special equipment under harsh working conditions.
▲ Long cycle life: ≥2000 times (80% capacity retention rate).
▲ Fast charging: Supports 1 to 2 hours of fast charging, suitable for high-intensity work.
▲ High-power discharge: The battery supports continuous high-current discharge, meeting the high-current requirements of high-power devices and ensuring their continuous and stable operation.
▲ Intelligent management: The BMS (Battery Management System) is equipped with functions such as overcharge protection, overdischarge protection, overcurrent protection, short-circuit protection, temperature protection, and fault diagnosis, making the battery more intelligent.
▲ Discharge temperature range: -40℃ to +70℃. In a low-temperature environment of -40℃, the battery's discharge efficiency is over 70%. A wider range of ambient temperature adaptability.
▲ Charging temperature: -20 ℃ to +50℃ range, with a wider adaptability to environmental temperatures.

III. Scheme Design
1. Battery selection
▲ Cell types: Ternary lithium batteries (ultra-low temperature, high energy density, high safety), lithium iron phosphate batteries (ultra-low temperature, high safety, long life), sodium-ion batteries (high safety, long life, good low-temperature performance). Different system cells are selected and matched according to different application scenarios.
▲ Battery combination configuration structure: Series and parallel schemes are designed based on the required voltage and capacity of the equipment to meet the requirements of different output voltage platforms.
▲ Structural design: IP65 to IP68 protection grade, shock-resistant structure, explosion-proof enclosure (suitable for extreme environments or flammable and explosive environments).

2. BMS Management System
Core functions:
▲ Real-time monitoring of the voltage, temperature, SOC (State of Charge), and SOH (State of Health) of individual battery cells.
▲ The battery charging active balancing technology enhances the consistency of usage among battery cells and extends the lifespan of the battery pack.
▲ The I2C/SMBUS/CAN/RS485 communication interface enables data interaction and communication with the main control system of the equipment.
▲ The Coulomb computing method makes the battery SOC more accurate and the battery smarter.

3. Charging solution
▲ Charging equipment: Customized smart charger/charger/charging cabinet, supporting constant current and constant voltage (CC-CV) charging.
▲ Charging strategy: Select fast charging or slow charging mode based on the working conditions to prevent battery overload.
▲ Intelligent control and management: Based on the technical performance characteristics of the battery, the battery charging process and fault diagnosis are intelligently controlled.

IV. Safety and Compliance
1. Safety protection
▲ Thermal management: By adopting a reasonable structural layout, thermal runaway is reduced. Air cooling/liquid cooling systems can be used (for high-power scenarios) to ensure temperature uniformity during battery use and effectively control battery thermal runaway.
▲ Fault protection: Multiple hardware protection mechanisms such as overcharge, overdischarge, short circuit, overcurrent, and over-temperature.
▲ Fault protection: Multiple hardware protection mechanisms such as short circuit, overcurrent, and over-temperature.
▲ Explosion-proof certification: The design can pass various safety regulations certifications.

2. Standard compliance
▲ It complies with national standards such as GB31241-2022 (Safety Technical Specification for Lithium-ion Batteries and Battery Packs for Portable Electronic Products), GB 17761-2024 (Safety Technical Specification for Electric Bicycles), GB/T 34131 (Lithium Batteries for Power Storage), GB 38031 (Safety Requirements for Batteries for Electric Vehicles), etc.
▲ How to obtain domestic and international certifications: GB certification, UN38.3 certification, UL certification, IEC certification, CE certification and other various certification requirements.

V. Project Implementation Plan

VI. Economic Benefit Analysis
1.Cost comparison
▲ The initial investment in lithium batteries is higher than that in disposable batteries, but they can be recycled for a long time, significantly reducing the cost of use.
2. Energy-saving benefits:
▲ It can be recycled and significantly reduces energy consumption compared with disposable lead batteries.
3. Maintenance cost:
▲ Maintenance-free design reduces the cost of manual inspection and battery replacement.

VII. After-sales Service
1. Warranty period: 1 to 5 years of after-sales warranty, with a lifespan of over 500 to 200 cycles (whichever comes first).
2. Remote monitoring: According to the actual demand status, the cloud platform provides real-time monitoring of the battery status and early warning of potential faults.
3. Emergency Response: Respond within 4 hours, provide solutions within 8 hours, and offer on-site technical support within 24 to 48 hours.
Hint:
▲ The plan needs to be refined based on specific equipment parameters (such as voltage, capacity, and size limitations).
▲ If special environments (such as extreme cold, high temperature, and high humidity) are involved, corresponding protective designs need to be added.
▲ It is recommended to conduct joint debugging with the equipment manufacturer to ensure the compatibility of the battery with the entire machine system.