3S 40A 18650 Lithium Battery Protection Board

3S 40A 18650 Lithium Battery Protection Board is a smart protection circuit designed for 3-series 18650 lithium-ion battery packs. It safeguards batteries against overcharge, over-discharge, short circuits, and overcurrent. This 40A BMS (Battery Management System) board ensures efficient and safe performance in high-current applications such as e-bikes, power tools, and DIY battery packs.

Key Features:

• 3S Configuration: Supports 3-series 18650 lithium-ion battery packs.
• High Discharge Current: Capable of handling up to 40A continuous current.
• Advanced Protection: Provides overcharge, over-discharge, short circuit, and overcurrent protection.
• Balanced Charging: Maintains equal voltage across all 3 cells during charging.
• Compact Design: Lightweight and easy to install in battery enclosures or DIY projects.

Technical Specifications:

• Battery Type: 18650 Lithium-ion
• Number of Cells: 3 in series (3S)
• Continuous Discharge Current: 40A
• Charge Voltage: 12.6V (max)
• Overcharge Detection Voltage: 4.25V ± 0.05V
• Over-discharge Detection Voltage: 2.7V ± 0.1V
• Overcurrent Detection: 60A ± 5A
• Short Circuit Protection: Yes
• Temperature Protection: No (basic board)

Mechanical Specifications:

• Board Dimensions: Approx. 60mm × 45mm × 3mm
• PCB Thickness: 1.2mm
• Mounting Holes: None
• Board Material: FR-4 with solder mask

Wiring and Connection Diagram:

• B+ / B-: Connect to battery pack’s positive and negative terminals
• P+ / P-: Connect to output load or charging device
• B1 / B2 / B3: Connect between individual cell junctions
• Balance Wires: Ensure proper wiring for equal cell charging

Datasheet and Documentation:

• Download 3S 40A BMS Protection Board Datasheet (PDF)

Applications:

• Electric Bikes: Protects high-current 18650 packs used in e-bikes and scooters.
• Power Banks: Ensures safe and reliable performance in DIY portable chargers.
• Solar Battery Packs: Used in renewable energy battery storage setups.
• RC and Robotics: Safeguards lithium packs in hobby electronics and robotics.
• Power Tools: Supports safe operation of battery-powered hand tools.

Equivalent Models:

• 3S 25A BMS: Lower current version for moderate power applications
• 3S 60A BMS: Higher capacity variant for larger packs
• HX-3S-FL40A: Similar design from other BMS manufacturers

Package Includes:

• 1 x 3S 40A 18650 Lithium Battery Protection Board