The 3.7V Single-Cell Dual MOS Protection Board is a compact, essential safety module designed to protect single-cell lithium-ion and lithium-polymer batteries from overcharge, over-discharge, and short-circuit conditions. It is specifically engineered for 18650 cells, polymer pouch cells, and other 3.7V lithium batteries, making it an indispensable component for DIY battery packs, power banks, and portable electronics.
At the heart of the board is a dual MOS (Metal-Oxide-Semiconductor) protection circuit that provides comprehensive safety for your lithium battery. The circuit 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.
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 4.35V, preventing damage from excessive charging.
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Over-discharge protection — Disconnects the load when the battery voltage drops to approximately 2.4V to 3.0V, preventing deep discharge that can permanently damage the battery.
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Short-circuit protection — Instantly disconnects the output if a short circuit is detected, preventing dangerous current surges.
The board features pre-attached nickel plates that are spot weldable, making it easy to integrate directly into battery packs. The nickel strips allow you to spot-weld the protection board to the battery terminals, creating a secure, low-resistance connection without soldering directly to the battery. This is the preferred method for professional battery pack assembly.
The compact PCB design is sized to fit neatly alongside 18650 cells and polymer batteries, making it ideal for space-constrained applications. The board includes B+ and B- pads for battery connection, and P+ and P- pads for the protected output.
The 3.7V Single-Cell Protection Board is widely used in DIY power banks, 18650 battery packs, portable speakers, flashlights, vaping devices, RC vehicles, and any application where lithium battery safety is critical.
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 custom power bank, assembling an 18650 battery pack, or adding safety protection to a portable device, the 3.7V Single-Cell Dual MOS Protection Board provides a reliable, cost-effective solution. It is suitable for individual makers, students, and businesses purchasing in bulk for product development or educational programs.
Features
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Dual MOS protection circuit — Comprehensive safety for single-cell lithium batteries
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Overcharge protection — Disconnects charger at ~4.25V–4.35V
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Over-discharge protection — Disconnects load at ~2.4V–3.0V
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Short-circuit protection — Instant disconnection on fault
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Pre-attached nickel plates — Spot weldable for easy battery pack integration
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Compact PCB design — Sized for 18650 and polymer cells
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Simple connection — B+/B- for battery, P+/P- for protected output
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Wide application range — Power banks, battery packs, portable devices, DIY projects
Technical Specifications
| # | Parameter | Specification |
|---|---|---|
| 1 | Compatible Battery | 1S 3.7V lithium-ion / lithium-polymer |
| 2 | Overcharge Protection Voltage | ~4.25V – 4.35V |
| 3 | Over-discharge Protection Voltage | ~2.4V – 3.0V |
| 4 | Continuous Discharge Current | Variant dependent (typically 2A–6A) |
| 5 | Short-circuit Protection | Yes |
| 6 | MOS Type | Dual MOS |
| 7 | Connection Type | Pre-attached nickel plates (spot weldable) |
| 8 | Module Dimensions | Compact PCB for 18650/polymer cells |
