2S 20A 18650 Li-ion Battery Series BMS Charger Protection Module

Key Specifications:

• Series Rating: 2S (7.4V nominal, 8.4V fully charged)
• Maximum Current: 20A continuous discharge
• Battery Type: 3.7V Lithium-Ion (like 18650 cells)
• Charging Voltage: 8.4V – 9.0V DC

Core Protection Functions:

• Overcharge Protection: Stops charging when any cell hits ~4.25V.
• Over-discharge Protection: Cuts power when any cell drops below ~2.5V.
• Overcurrent Protection: Disconnects the load if current exceeds safety limits.
• Short Circuit Protection: Shuts down output instantly during a short circuit.

Standard Wiring Guide:

• B+: Connects to the positive terminal of the second battery.
• B-: Connects to the negative terminal of the first battery.
• BM: Connects to the middle junction between the two batteries.
• P+: Connects to the positive charge input and load output.
• P-: Connects to the negative charge input and load output.

Critical Safety Warnings:

• Do not mix old and new batteries in the pack.
• Use batteries with matching capacities and internal resistance.
• Double-check polarity before soldering to prevent board burnout.
• A high-current BMS requires thick wires rated for 20A performance.

Common Applications:

• Robotics: Powers small robot chassis, Arduino-based vehicles, and robotic arms.
• Portable Electronics: Powers handheld walkie-talkies, custom Bluetooth speakers, and LED camping lanterns.
• Backup Power: Acts as a mini-UPS for 5V–12V routers, modems, and security cameras.
• Power Tools: Drives low-power electric screwdrivers, mini vacuums, and engraving pens.
• Smart Home Devices: Energizes motorized window blinds, smart door locks, and outdoor sensor arrays.