3S 12V 12.6V 4A-6A 18650 Lithium Battery BMS Protection Board

3S 12V 12.6V 4A-6A 18650 Lithium Battery BMS Protection Board is a slim, low-power 3-series (3S 11.1V nominal / 12.6V full charge) Battery Management System (BMS) strip designed for compact 3-cell 18650, 14500, and LiPo battery packs. Supporting 4A to 6A continuous working current (up to 9A–10A instantaneous peak) with less than 30µA quiescent drain, it fits directly inside 3-slot 18650 holders and shrink-wrapped packs for 12V Wi-Fi router UPS backups, LED strips, CCTV cameras, and Arduino projects.

Key Features:

• Compact 3S (11.1V / 12.6V) Protection Strip: Narrow ribbon form factor tucks neatly alongside 18650 cells without adding bulk to small 12V battery enclosures.
• 4A–6A Continuous / 9A–10A Peak Current: Ideal for low-to-medium current 12V electronics (up to 50W–70W) such as routers, modems, LED lighting, and instrumentation.
• Individual 3-Cell Voltage Supervision: Monitors `B-`, `B1`, `B2`, and `B+` to cut off overcharging at 4.25V–4.35V/cell and prevent deep discharge below 2.3V–3.0V/cell.
• Short-Circuit Protection with Delayed Self-Recovery: Protects the battery pack and load wiring against accidental short circuits.
• Ultra-Low <30µA Standby Current: Rated for >30,000 hours of service life with negligible idle battery drain.

Technical Specifications:

• Supported Battery Configuration: 3S (3 Series 3.7V Li-ion / 18650 / 14500 / LiPo Cells — 11.1V Nominal)
• Charging Voltage: 12.6V to 13.0V DC CC/CV
• Continuous Working Current: 4A to 6A (6A–8A Upper Limit)
• Instantaneous Peak Current: 9A to 10A
• Overcharge Voltage Range: 4.25V to 4.35V ± 0.05V per cell
• Over-Discharge Voltage Range: 2.30V to 3.00V ± 0.05V per cell
• Quiescent Current: < 30 µA | Internal Resistance: < 100 mΩ
• Operating Temperature Range: -40°C to +50°C

Mechanical Specifications:

• PCB Material: FR-4 Fiberglass Strip PCB
• Terminals: 6 × Tinned Solder Pads (`B-`, `B1`, `B2`, `B+`, `P+`, `P-`)

Dimensions:

• Length: ~50 mm
• Width: ~16 mm
• Thickness: ~3.0 mm
• Weight: ~5 g

Pinout and Wiring:

• B- (0V): Connect to Cell 1 Negative terminal.
• B1 (3.7V): Connect between Cell 1+ and Cell 2-.
• B2 (7.4V): Connect between Cell 2+ and Cell 3-.
• B+ (11.1V/12.6V): Connect to Cell 3 Positive terminal.
• P+ & P-: Output/input terminals to 12V load and 12.6V CC/CV charger.
• Important Note: Designed for 4A–6A electronic loads (routers, LEDs, Arduino). Do NOT use this 4A board on 12V cordless drills or 775 motors (use the `3S 25A` or `3S 40A` BMS instead).

Datasheet Reference:

• Protection Architecture: 3-Series Li-Ion Protection IC + Low-Side Dual N-Channel MOSFET Stage

Commonly Used in:

• 12V Wi-Fi Router, Fiber ONT, and CCTV Camera Mini-UPS Packs
• 12V LED Strip Lamps, Solar Garden Lights, and Camping Lanterns
• Arduino, Raspberry Pi (with 5V Buck), and Sensor Telemetry Packs
• Portable Bluetooth Speakers and Handheld Test Equipment

Applications:

• Combines with a 3-slot 18650 battery holder (`PID 3223`) to build a compact 12V 2500mAh–3500mAh rechargeable battery pack.
• Provides uninterruptible 12V backup power for home Wi-Fi routers and security cameras.
• Protects 3-cell 18650 packs against overcharging and deep discharge in solar lamp circuits.

Equivalent Models:

• HX-3S-FL10A 3S 11.1V 12.6V 10A Lithium Battery BMS Protection Board: Higher-current 10A 3S BMS strip in the same compact form factor.
• 3S 12.6V 20A 18650 Li-ion Lithium Battery BMS Protection Board: 20A 3S BMS module for motor and high-power loads.

Package Includes:

• 1 × 3S 12V 12.6V 4A-6A 18650 Lithium Battery BMS Protection Board