Portable lighting battery solution

Portable lighting battery design scheme

Brief introduction of battery:

1. Product function introduction and parameters:
     The portable lighting battery integrates various functions such as single chip microcomputer software control power display, hardware protection circuit, software secondary protection, temperature collection, voltage collection and so on.
1) Lithium battery pack model design requirements: 18650-2S/6.8Ah/7.4V/50.32Wh.
2) Input and output characteristics: the same port is used for input and output.
    1. Input characteristics: A matching charger is designed to charge the lithium battery pack.
    2. Output characteristics: The battery outputs a voltage of 6.0-8.4 V to power the mobile lighting to meet normal use.

3) Power display: Turn on the mobile lighting and the power display switch button to display the current stored power of the battery in real time.
4) Basic characteristics of the protection board
    1. Single cell overcharge protection voltage: 4.2±0.025V
    2. Single cell overcharge recovery voltage: 4.10±0.05V
    3. Single cell over-discharge protection voltage: 2.8±0.10V
    4. Single cell over-discharge recovery voltage: 3.00±0.10V
    5. Combined battery overcurrent protection value: 6.00～15.00 A
    6. Electricity display design scheme

7. The finished battery also has short-circuit protection.
5) Design requirements for battery cycle life: more than 500 times (national standard charge and discharge standards)
6) Design requirements for battery dimensions: refer to actual battery case dimensions

 

2. Product design plan:
1) Electricity display module: Control the LED lighting method to reflect the current electric quantity of the battery through the MCU software, which is convenient and intuitive.
2) Protection module combining software and hardware: It is mainly a protection circuit designed for rechargeable lithium battery packs. Due to the chemical characteristics of lithium batteries, protections such as overcharge, overdischarge, short circuit, overcurrent, and overtemperature are required Function to avoid safety factors such as burning and explosion. This battery is designed with a hardware protection circuit plus a single-chip microcomputer software secondary protection, which is more secure.
3) Protection IC (Protection IC): The main protection function chip of the design scheme, which performs online real-time monitoring of the functions of overcharging, overdischarging, overcurrent, short circuit and so on, so that the batteries can work in a safe, stable and efficient range.
4) Selection of battery cell: This project uses imported 18650 lithium ion cylindrical battery/18650/3400mAh/3.6V Li-ion cell.
5) Field-effect tube (MOSFET): MOSFET tube plays a role of switching in the protection circuit.
6) Connector: Use DC plug to connect with the host.

7) Battery shell: The overall appearance adopts the appearance of sprayed rubber paint, which constitutes the overall battery model.

               (Protection board schematic diagram and battery pack structure)