Specification:

Features:

1. Full 3S Battery Pack Compatibility

• Designed specifically for 3-series (3S) lithium-ion battery packs (such as 18650 or LiPo cells).

• Supports 11.1V nominal and 12.6V fully charged voltage levels.

• Perfect for projects requiring a stable and protected 12V lithium power source.

⚙️ 2. High Current Handling – Up to 40A Continuous Discharge

• Built to handle up to 40A continuous discharge current, suitable for high-drain applications like:

  • Power tools (drill motors, screwdrivers)

  • Electric bikes and scooters

  • DIY portable inverters or solar systems

• Ensures consistent power delivery without tripping or overheating.

🧠 3. Smart Overcharge Protection

• Prevents each cell in the pack from exceeding 4.25V (±0.05V).

• Automatically stops charging when a cell reaches its safe upper voltage limit.

• Protects the battery from bloating, damage, or fire hazards due to overvoltage.

🧯 4. Over-discharge Protection

• Automatically cuts off the output load when any cell drops below 2.7V (±0.1V).

• Prevents irreversible battery damage or capacity loss due to deep discharge.

• Increases overall pack lifespan.

⚡ 5. Overcurrent and Short Circuit Protection

• Built-in sensors detect:

  • Overcurrent draw

  • Short circuits

• Instantly disconnects the output in dangerous scenarios to prevent fire, overheating, or damage to the battery and connected devices.

• Auto-recovery after the fault is cleared—no manual reset required.

🔄 6. Active Cell Balancing

• Ensures that all three battery cells are charged to the same voltage level (~4.2V each).

• Automatically activates during charging if voltage imbalance is detected.

• Helps prevent overcharging one cell while undercharging others—critical for safety and long-term health of the battery pack.

♻️ 7. Automatic Recovery Function

• After protection is triggered (like overcurrent or over-discharge), the BMS will automatically restore normal operation once conditions return to safe levels.

• No need for manual resets or intervention.

🌡️ 8. Thermal Safety Support (optional in some versions)

• Some versions may support temperature sensors or have thermal pads for heat dissipation.

• Helps regulate temperature during high-load conditions when paired with a heat sink.

🔌 9. Dual Purpose Output Ports (P+ / P-)

• Shared output terminals for both:

  • Charging

  • Discharging

• Simplifies wiring, especially for compact or DIY systems.

🔩 10. Industrial-Grade PCB Design

• Durable, high-quality multi-layer PCB with thick copper tracks for high current flow.

• Compact and lightweight—fits easily into enclosures or battery packs.

• Reliable components including MOSFETs, resistors, and ICs built for durability and safety.

📦 11. Plug-and-Play Ready for DIY Builders

• Clearly labeled terminals (B+, B-, P+, P-, B1, B2) for straightforward installation.

• Ideal for:

  • DIY battery pack builders

  • Makers and hobbyists

  • Engineers and technicians

🔋 12. Wide Compatibility with Lithium Chemistries

• Suitable for most Li-ion and Li-Po cells including 18650, 26650, 14500, and flat-pack lithium batteries.

• Works with brands like Samsung, LG, Panasonic, and more.

🛡️ 13. Reverse Connection Protection (for some versions)

• Prevents damage to the board or batteries if terminals are accidentally reversed.

• Increases the safety margin for DIY users or first-time battery pack builders.

Description:

The 3S 40A BMS (Battery Management System) is a high-performance protection circuit board designed for 3-series (3S) 18650 lithium-ion battery packs, operating at a nominal voltage of 11.1V, with a charging voltage up to 12.6V. This BMS is engineered to safeguard battery packs from overcharge, over-discharge, overcurrent, and short circuits—ensuring optimal performance, safety, and extended battery lifespan.

This model features active cell balancing, allowing each cell to be charged equally, which improves battery health and efficiency over time. It is ideal for power tools (like drill motors), e-bikes, solar energy systems, electric vehicles, DIY battery packs, and other high-drain applications. 

This 3S 40A Battery Management System (BMS) is a high-performance, intelligent protection circuit board designed for use with 3-cell (3S) lithium-ion (Li-ion or LiPo) battery packs, most commonly made using 18650 cells. It enables safe charging and discharging by managing the voltage, current, and balance across all three cells.

The BMS supports a maximum charge voltage of 12.6V and a nominal operating voltage of 11.1V, making it ideal for powering tools, electric vehicles, and energy storage systems. It also integrates a balancing circuit, which equalizes cell voltages during charging—boosting battery performance and lifespan.

Built with heavy-duty components, this module can handle a continuous discharge current of up to 40A, providing reliable power delivery for high-drain applications such as cordless drills, e-bikes, inverters, solar battery packs, hoverboards, and portable power stations.