This Battery Management System (BMS) with Buck-Boost Converter is designed for lithium battery applications, providing a flexible voltage range of 3-5V. It is particularly useful in projects requiring stable 3.3V or 5V outputs. The system includes a charging circuit, protection circuit, and a DC-DC buck-boost converter, ensuring consistent voltage, enhanced battery safety, and adaptability for various devices.
The key components of the module include:
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Charging Circuit: Utilizing the MCP73831, this circuit facilitates the selection of charge current via a resistor and incorporates an indicator diode.
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Protection Circuit: Protection is ensured by DW01A and FS8205A. The FS8205A connects the battery's negative to the common ground, with DW01A controlling battery operation. The transistor disconnects the battery in cases of discharge, overcharge, short circuit, etc.
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DC-DC Buck-Boost Converter: Employing TPS63020DSJR, this component enables voltage conversion. The goal is to maintain a constant voltage level regardless of the battery charge, acting as a step-up converter when voltage is low and a step-down converter when it's high.
In summary, this module facilitates battery charging, provides protection, and allows for adjustable output voltage.
Refer to the complete schematic in
BMS_Buck-Boost.pdf.
-Band+Bare used to connect the battery.+B,+V, andGNDare for connecting to the load, with+Bused for measuring battery voltage.
- While using the module during charging and securing the load, certain limitations exist when the level on the
VBUSline is high. At this point, transistor Q2 (refer to the schematic here) doesn't pass the voltage. This is done to optimize battery charge. If you want to useVBUSfor the DC-DC converter during charging, employ diodeD4and an additional diode to prevent current from+VCC_INto+BATT.