The BMS 1S 3.7V Lithium Battery Protection Board is a high-current safety module designed to protect single-cell lithium-ion and lithium-polymer batteries from overcharge, over-discharge, and overcurrent conditions. With a 15A overcurrent protection rating, this board is specifically engineered for high-drain applications where standard protection boards cannot handle the current requirements.
At the heart of the board is a BMS (Battery Management System) protection circuit that continuously monitors the battery voltage and current, disconnecting the load or charger if any parameter exceeds safe limits. This protects both the battery and your connected devices from damage, extending battery lifespan and ensuring safe operation in demanding applications.
The board provides three critical protection functions:
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Overcharge protection — Disconnects the charger when the battery voltage reaches approximately 4.25V to 4.3V, preventing damage from excessive charging.
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Over-discharge protection — Disconnects the load when the battery voltage drops to approximately 2.5V to 3.0V, preventing deep discharge that can permanently damage the battery.
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Overcurrent protection — Disconnects the output when current exceeds 15A, protecting against short circuits and excessive loads.
The 15A overcurrent rating makes this board suitable for high-power applications such as power tools, high-drain flashlights, electric skateboards, e-bike batteries, vaping mods, and other devices that draw significant current. Standard protection boards typically max out at 2A–6A, so this board fills an important gap for high-current single-cell applications.
The board features a solder pad design that supports both direct soldering and spot welding. The exposed pads allow you to solder wires directly to the board, while also being compatible with spot-welded nickel strips for professional battery pack assembly. The compact PCB design is sized to fit neatly alongside 18650 cells and polymer batteries.
The BMS 1S Protection Board is widely used in DIY power banks, 18650 battery packs, power tools, portable speakers, high-power flashlights, RC vehicles, electric skateboards, and any application where lithium battery safety is critical and high current is required.
Important Note: This protection board is designed for single-cell (1S) 3.7V lithium batteries. For multi-cell packs, each cell should have its own protection board, or a multi-cell BMS should be used. Always verify the voltage and current ratings match your application before installation.
Whether you are building a high-drain power bank, assembling an 18650 battery pack for power tools, or adding safety protection to a high-current portable device, the BMS 1S 3.7V Lithium Battery Protection Board provides a reliable, high-current solution. It is suitable for individual makers, students, and businesses purchasing in bulk for product development or educational programs.
Features
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15A overcurrent protection — High-current capability for demanding applications
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Comprehensive protection — Overcharge, over-discharge, and overcurrent protection
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BMS protection circuit — Reliable, proven battery management technology
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Solder pad design — Supports both direct soldering and spot welding
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Wide compatibility — Works with 18650 and polymer lithium cells
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Compact PCB design — Sized for space-constrained battery packs
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Simple connection — B+/B- for battery, P+/P- for protected output
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Wide application range — Power tools, e-bikes, high-drain devices, DIY projects
Technical Specifications
| # | Parameter | Specification |
|---|---|---|
| 1 | Compatible Battery | 1S 3.7V lithium-ion / lithium-polymer |
| 2 | Overcharge Protection Voltage | ~4.25V – 4.3V |
| 3 | Over-discharge Protection Voltage | ~2.5V – 3.0V |
| 4 | Overcurrent Protection | 15A |
| 5 | Continuous Discharge Current | Up to 15A (variant dependent) |
| 6 | Connection Type | Solder pads (spot welding supported) |
| 7 | MOS Type | High-current dual MOS |
| 8 | Module Dimensions | Compact PCB for 18650/polymer cells |
