3.7V 3.4Ah Portable Solar Energy Backup Power Supply Design Scheme

Foreword: (keyword: mobile power supply) mobile backup power supply meets the digital product demand of charging outdoor. Change the energy storage by nature renewable energy sources or use household electric energy storage to solve the digital product issues of power cut and power supply outdoor. The main features of the products are portability, high efficiency and diversity.

Portable solar energy backup power supply design scheme

Portable solar energy backup power supply takes solar energy as conversion source, transforms solar energy into electric energy, and stores electric energy through lithium battery, so as to achieve the purpose of outdoor power supply of mobile digital products. The whole product adopts single lithium ion battery with large capacity as energy storage device. It charged by duel charging mode including sunlight charging received by solar panel and charger with two-way charging mode. It has 5V output and its maximum output current is 2A, which meets the power supply demand of relevant digital products. Precise LED battery display can effectively show the user for remaining capacity of battery in percentage on LED lighting, which is very efficient and intuitive.

The design requirement of lithium ion battery pack types: 6535134/3.4Ah/3.7V

Transformation parameters of solar panel: 5V/350mA

Design requirements of protective circuit:

Over-charged protection voltage of single battery: 4.35±0.25V

Over-charged recovery voltage of single battery: 4.15±0.50V

Over-discharged protection voltage of single battery: 2.40±0.08V

Over-discharged recovery voltage of single battery: 3.00±0.10V

Over-discharge cut-off current (10ms) 5~8A

Over temperature protective value (restorable): 70±5℃

The finished product has protective function of short circuit and reverse-charging.

Design requirement of cycle life: 300~500 times (national standard of charging and discharging)

Design requirements of battery dimension:

Portable solar energy backup power supply design scheme:

Protection IC: it is the protective circuit designed for rechargeable lithium ion battery pack. Because of the chemical characteristics of lithium ion battery, it needs protective function of overcharging, over-discharging, short circuit, overcurrent, etc. so as to avoid combustion, explosion, etc.

Voltage reduction: contain solar panel (5V/350mA) and input voltage reduction module of 5V charger. Based on the chemical characteristics of lithium ion battery, design voltage reduction function of pre-charging, constant current and charging under constant voltage.

Raising voltage module: adopt constant voltage of 5V output circuit. the maximum output current is 2A.

Charger module: adopt 5V/1.5V charger

LED display: display the battery capacity by voltage comparison.

Solar panel: transfer solar energy into electric energy. The output parameter is 5V/350mA.

Lithium ion battery: PL6535134/3.4Ah/3.7V（ATL）

The structure diagram of portable solar energy backup power supply design scheme:

The product pictures of portable solar backup power supply: