1S 3A BMS

This 1S 3A BMS 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

• Pre-Soldered Nickel Strip – Easy integration with 18650 cells via spot welding.

• Complete Battery Protection – Overcharge, over-discharge, overcurrent, and short-circuit protection.

• Ultra-Low Self-Consumption – Preserves battery life with ≤3µA idle current.

• Auto-Recovery Design – Recovers automatically from fault conditions.

Specifications

• Battery Type: 1S 3.7V Li-ion / Li-Polymer

• Max Charging Current: 2A

• Max Discharging Current: 3A (continuous)

• Overcharge Voltage: 4.25V ± 0.05V

• Overcharge Release Voltage: 4.23V ± 0.05V

• Over-discharge Voltage: 2.0–2.1V

• Over-discharge Release Voltage: 2.3V ± 0.1V

• Overcurrent Detection Voltage: 200mV ± 25mV

• Overcurrent Detection Current: 3A

• Short Circuit Protection: Yes (250µs detection delay)

• Working Current: ≤20µA

• Sleep Current (Over-discharge): ≤20µA

• Self-Consumption: ≤3µA

• Internal Resistance: ≤20mΩ

• Operating Temperature: -20°C to +40°C

Installation & Precautions

• Match battery cells before installation (≤0.05V voltage difference).

• For used batteries, ensure cells are healthy (check with multimeter).

• Do not screw terminal joints—use spot welding for 18650 cells.

• Always check voltage across cells before connecting to avoid damage to the protection IC.

Applications

• 18650 Li-ion Battery Packs

• DIY Portable Chargers

• Low-power Devices & Embedded Systems

• Smart Flashlights

• Mini UPS Units

• Battery Swapping Modules