1S 4A BMS Protection Board for 3.7V Li-ion Battery – 259-FDC-3540

Product Description

Protect compatible single-cell lithium-ion battery packs with the 259-FDC-3540 1S 4A BMS Protection Board. This compact battery protection module is designed for suitable 3.6V/3.7V nominal lithium-ion and lithium-polymer battery applications, including compatible 18650 cells and small rechargeable battery projects.

The board provides advertised protection against overcharging, excessive discharge, overcurrent and short circuits. It helps disconnect the protected battery circuit when specified electrical fault conditions are detected, supporting safer operation when correctly installed with a suitable cell, charger and load.

Its slim PCB format is useful for space-conscious battery-pack assemblies, portable electronics, DIY electronics and compatible low-voltage projects.

Key Features

• Single-Cell Protection: Designed for compatible 1S lithium-ion and lithium-polymer battery packs.

• Advertised 4A Working Current: Suitable for applications within the board's verified current and thermal limits.

• Overcharge Protection: Helps interrupt charging when the configured overcharge threshold is reached.

• Over-Discharge Protection: Helps prevent continued discharge below the board's protection threshold.

• Overcurrent and Short-Circuit Protection: Advertised fault-protection functions help disconnect the protected circuit under specified abnormal conditions.

• Compact PCB Design: Approximately 35mm long, suitable for compact battery-pack integration.

• Protected Battery Connections: Uses battery and output terminals identified as B+, B−, P+ and P− in the seller's wiring information.

Technical Specifications

• Model: 259-FDC-3540

• Configuration: 1S, single-cell battery protection

• Compatible battery chemistry: Lithium-ion / lithium-polymer, subject to cell specifications

• Nominal battery voltage: 3.6V/3.7V

• Advertised charging voltage: 4.2V

• Advertised working current: 4A

• Advertised peak / overcurrent figure: 5A; operating conditions and duration require supplier confirmation

• Advertised overcharge threshold: 4.25V ± 0.05V

• Advertised over-discharge threshold: approximately 2.45V–2.5V

• Advertised protection: Overcharge, over-discharge, overcurrent and short circuit

• Approximate dimensions: 35 × 4mm; thickness reported as approximately 2–2.2mm

• Connections: B+, B−, P+, P−, according to the board's wiring configuration

• Package contents: 1 × 1S battery protection board

Specifications are based on available retailer listings. Confirm exact thresholds, continuous current, dimensions, and chip marking for the supplied batch.

Applications

• Compatible 18650 single-cell battery packs

• Suitable single-cell lithium-polymer battery assemblies

• Portable electronic devices

• DIY battery-powered projects

• Small low-voltage electronics within the board's electrical limits

Installation and Safety Notes

1. Confirm that the battery is a compatible single-cell lithium-ion or lithium-polymer type.

2. Identify the B+, B−, P+ and P− pads from the supplied board's markings or verified wiring diagram before soldering.

3. Incorrect polarity or wiring can damage the protection board and battery.

4. Use a suitable lithium-ion charger with the correct charging profile; this board is not a standalone charger.

5. Ensure the cell, wiring, load and board are all suitable for the required current.

6. Do not use this 1S board for series-connected multi-cell battery packs.

7. Insulate exposed connections and avoid short circuits during installation.

Package Includes: 1 × 259-FDC-3540 1S 4A lithium battery protection board.