Written by 
5PCS 1S 3.7V 4A Li‑ion Battery Charging Protection Board – 2 MOS BMS for 18650 Cells
Upgrade your DIY power projects with our compact, high‑performance 5PCS 1S 3.7V 4A Li‑ion Battery Charging Protection Board. Designed specifically for 18650 lithium‑ion cells, this 2‑MOS BMS module delivers reliable over‑charge, over‑discharge, short‑circuit, and over‑current protection while maintaining a low voltage drop for maximum efficiency.
Key Highlights
- ✅ 1‑Series (1S) Design – Perfect fit for single 18650 cells (3.7 V nominal).
- ✅ 4 A Continuous Discharge – Handles demanding loads without overheating.
- ✅ 2 MOSFETs (2 MOS BMS) – Low RDS(on) for high efficiency and minimal heat.
- ✅ Comprehensive Protection – Over‑charge, over‑discharge, over‑current, and short‑circuit safeguards.
- ✅ Easy Solder‑On Pads – Quick installation on any 18650 holder or custom PCB.
- ✅ Compact Size – 30 mm × 20 mm footprint saves space in tight enclosures.
Technical Specifications
- Battery Type: 18650 Li‑ion (3.7 V nominal)
- Configuration: 1S (single cell)
- Charging Voltage: 4.20 V ± 0.05 V
- Charging Current: 0.5 A – 1 A (adjustable via external resistor)
- Discharge Current: 4 A (continuous), 6 A (peak)
- Protection Thresholds: Over‑charge at 4.25 V, Over‑discharge at 2.5 V, Over‑current at 4.5 A
- Operating Temperature: –20 °C to +60 °C
- Dimensions: 30 mm × 20 mm × 3 mm
- Package: 5‑piece kit (pre‑tested, ready to use)
Why Choose This BMS Module?
Safety is paramount when working with lithium‑ion cells. Our 2 MOS BMS board provides fast response times and precise voltage monitoring, ensuring your battery pack stays within safe limits. The low internal resistance of the MOSFETs reduces power loss, extending runtime for portable devices, RC models, flashlights, and DIY power banks.
Ideal Applications
- DIY power banks and portable chargers
- RC drones, helicopters, and car accessories
- Flashlights, headlamps, and outdoor lighting
- Electronic hobby projects and Arduino/ESP32 integrations
- Prototype battery management for wearable tech
Installation & Usage Tips
Simply solder the B+, B‑, and P‑ pads to your 18650 holder or custom board. Connect a charger (5 V – 6 V) to the “CHG” pins, and your load to the “OUT” terminals. The board will automatically manage protection cycles, giving you peace of mind during operation.
Customer Support
Each pack includes a detailed wiring diagram and a 12‑month warranty. Our technical support team is ready to help you with any installation questions or custom configuration needs.
Order now and power your next project with confidence using the reliable 5PCS 1S 3.7V 4A Li‑ion Battery Charging Protection Board!
Price: Original price was: $ 3.78.$ 1.85Current price is: $ 1.85.