1S 3.7V 9A 6-MOSFET BMS Li-ion 18650 Battery Protection Board

1S 3.7V 9A 6-MOSFET BMS Li-ion 18650 Battery Protection Board is a high-current single-cell (1S 3.7V/4.2V) lithium-ion Battery Management System (BMS) strip populated with 6 parallel low-resistance power MOSFETs (`8205A` array). While standard 1S PCM strips only support 2A–3A and trip on motor or high-wattage startups, this 6-MOSFET board supports 9A to 12A continuous discharge (up to 15A peak) for high-drain single-cell 18650/21700/26650 cells and multi-cell parallel (`1S2P` to `1S6P`) lithium battery packs.

Key Features:

• 6 Parallel Power MOSFETs for 9A–15A High Current: Six onboard dual N-channel MOSFETs dramatically lower internal path resistance (≤ 20 mΩ) and support 9A–12A continuous discharge and 15A peak current.
• Ideal for Parallel 1S Battery Packs (`1S2P`–`1S6P`): Easily manages 5 to 6 parallel-connected 18650 cells in high-capacity 3.7V power banks, tactical flashlights, and cordless screwdrivers.
• 4-Stage Hardware Cell Protection: Provides precision 4.25V overcharge cut-off, 2.50V over-discharge cut-off, overcurrent protection, and automatic short-circuit recovery.
• Ultra-Low Quiescent Drain: Consumes less than 30µA in standby, preserving stored charge over months of storage.
• Slim Strip Form Factor with Nickel Solder Tabs: Compact rectangular strip sits directly along the side or end of an 18650 cylinder pack.

Technical Specifications:

• Supported Battery Chemistry: 1S 3.7V Nominal (4.2V Charge) Li-ion / 18650 / 21700 / 26650 / LiPo (Single Cell or Parallel `1SnP` Pack)
• MOSFET Configuration: 6 × Parallel Power MOSFETs
• Continuous Working Current: 9A to 12A
• Instantaneous Peak Current Limit: 15A to 17A
• Charging Voltage: 4.20V to 4.25V DC (CC/CV)
• Overcharge Detection Voltage: 4.25V ± 0.05V (Release: 4.15V ± 0.05V)
• Over-Discharge Detection Voltage: 2.50V ± 0.05V (Release: 3.00V ± 0.10V)
• Quiescent Current: < 30 µA
• Internal Circuit Resistance: < 20 mΩ

Mechanical Specifications:

• PCB Material: FR-4 Fiberglass Strip PCB with Exposed Tinned/Nickel Solder Pads
• Terminals: 4 × Solder Pads (`B+`, `B-`, `P+`, `P-`)

Dimensions:

• Length: ~35 mm to 40 mm
• Width: ~7.5 mm
• Thickness: ~2.2 mm
• Weight: ~2.5 g

Pinout and Wiring:

• B+: Connect directly to the positive (+) pole of the 3.7V cell or parallel 1S cell group.
• B-: Connect directly to the negative (-) pole of the 3.7V cell or parallel 1S cell group.
• P+: Positive output/input terminal to load and 4.2V charger.
• P-: Negative output/input terminal to load and 4.2V charger.
• Activation Note: After first soldering the battery, connect a 4.2V charger to `P+`/`P-` briefly if output reads 0V to wake the protection IC.

Datasheet Reference:

• Protection Architecture: DW01A / S-8261 1S Li-Ion Protection IC + 6 × FS8205A Dual N-Channel MOSFETs

Commonly Used in:

• 3.7V Cordless Screwdrivers, Mini Drills, and Rotary Tools
• High-Lumen CREE / XHP70 Tactical 18650/26650 Flashlights
• Parallel 1S5P / 1S6P 18650 Battery Packs for Solar Lights
• Portable Soldering Irons, Electric Shavers, and Handheld Fans

Applications:

• Protects 3.7V cordless screwdriver and mini-grinder battery packs where a 3A 2-MOSFET BMS trips immediately on motor stall/startup current.
• Safeguards high-capacity 1S5P (10,000mAh–15,000mAh) parallel 18650 solar lamp batteries up to 9A–12A continuous draw.
• Adds short-circuit and over-discharge safety to unprotected flat-top 18650 and 26650 cells.

Equivalent Models:

• 1S 3.7V 3A Li-ion BMS PCM Battery Protection Board: Standard 2-MOSFET 3A protection strip for low-power 1S applications.
• 1S 3.2V 30A Single-Cell LiFePO4 Lithium Iron Phosphate BMS Protection Board: 1S 30A BMS specifically for 3.2V LiFePO4 cells.

Package Includes:

• 1 × 1S 3.7V 9A 6-MOSFET BMS Li-ion 18650 Battery Protection Board