This 1S 3A BMS Protection Board is designed for single-cell 3.7V lithium batteries such as 18650 or polymer Li-ion cells. It features 2 MOSFETs for precise control of charging and discharging, offering robust protection against overcharge, over-discharge, overcurrent, and short circuits.
This version comes pre-soldered with a nickel strip, making it ideal for spot-welding directly onto 18650 cells. It is suitable for compact battery pack assemblies where space and safety are a priority.
Key Features
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Pre-Soldered Nickel Strip – Easy integration with 18650 cells via spot welding. 
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Complete Battery Protection – Overcharge, over-discharge, overcurrent, and short-circuit protection. 
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Ultra-Low Self-Consumption – Preserves battery life with ≤3µA idle current. 
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Auto-Recovery Design – Recovers automatically from fault conditions. 
Specifications
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Battery Type: 1S 3.7V Li-ion / Li-Polymer 
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Max Charging Current: 2A 
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Max Discharging Current: 3A (continuous) 
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Overcharge Voltage: 4.25V ± 0.05V 
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Overcharge Release Voltage: 4.23V ± 0.05V 
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Over-discharge Voltage: 2.0–2.1V 
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Over-discharge Release Voltage: 2.3V ± 0.1V 
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Overcurrent Detection Voltage: 200mV ± 25mV 
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Overcurrent Detection Current: 3A 
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Short Circuit Protection: Yes (250µs detection delay) 
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Working Current: ≤20µA 
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Sleep Current (Over-discharge): ≤20µA 
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Self-Consumption: ≤3µA 
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Internal Resistance: ≤20mΩ 
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Operating Temperature: -20°C to +40°C 
Installation & Precautions
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Match battery cells before installation (≤0.05V voltage difference). 
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For used batteries, ensure cells are healthy (check with multimeter). 
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Do not screw terminal joints—use spot welding for 18650 cells. 
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Always check voltage across cells before connecting to avoid damage to the protection IC. 
Applications
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18650 Li-ion Battery Packs 
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DIY Portable Chargers 
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Low-power Devices & Embedded Systems 
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Smart Flashlights 
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Mini UPS Units 
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Battery Swapping Modules