LiFePO4 Battery Protection Board BMS 4S 30A 12V with Cell Balancing

The 4S 30A LiFePO4 Battery Management System (BMS) is a protection and cell-balancing module designed for 12V-class lithium iron phosphate battery packs. It supports four LiFePO4 cells or cell groups connected in series and provides a rated current path of up to 30A for compatible battery applications.

A 4S LiFePO4 battery pack has a nominal voltage of approximately 12.8V and a typical full-charge voltage of 14.6V. The BMS monitors the battery's cell-group voltages and helps protect the pack against abnormal operating conditions. Its integrated passive cell-balancing circuit helps reduce voltage differences between series-connected cell groups during the balancing process.

This module uses a common-port configuration, allowing charging and discharging through the designated shared connection. The compact PCB includes high-current switching components, battery connection terminals, a cell-balancing circuit, and a multi-pin balance connector. A balance wiring harness is included for connecting the board to the individual cell groups.

The 4S 30A LiFePO4 BMS is suitable for DIY battery packs, backup power systems, solar energy storage, portable power boxes, and other equipment using compatible 12V LiFePO4 batteries. It is a protection component rather than a standalone charger, so a dedicated 14.6V CC/CV charger suitable for a 4S LiFePO4 pack is required.

For reliable operation, use cells with compatible chemistry and suitable capacity and condition. Follow the board's connection diagram carefully, and select wiring, connectors, and loads that can safely handle the expected current. Actual current capability depends on installation, cooling, wiring, and operating conditions.

Features:

• Designed for 4S LiFePO4 battery packs

• Suitable for 12V-class lithium iron phosphate systems

• Rated current of up to 30A

• Integrated passive cell-balancing function

• Common-port charging and discharging configuration

• Onboard MOSFET switching components

• Dedicated cell-voltage balance connector

• Compact PCB with mounting holes

• Includes a balance wiring harness

Specifications:

• Product Type: Battery Management System / Protection Board

• Battery Chemistry: LiFePO4 (Lithium Iron Phosphate)

• Series Configuration: 4S

• Nominal Pack Voltage: 12.8V

• Typical Full-Charge Voltage: 14.6V

• Rated Current: 30A

• Port Configuration: Common port

• Cell Balancing: Passive balancing

• Main Connections: B- and C- solder pads, with positive and cell-tap connections according to the wiring diagram

• PCB Dimensions: Approximately 62 × 45 × 1.5mm

• Balance Cable Length: Approximately 35cm

• Weight: Approximately 15g

• Charging Requirement: Compatible 14.6V CC/CV charger for a standard 4S LiFePO4 pack

Exact overcharge, over-discharge, overcurrent, and short-circuit protection thresholds, as well as the maximum charging current, should be confirmed against the specific board revision.

Applications:

• DIY 12V LiFePO4 battery packs

• Solar energy storage systems

• Backup power and UPS battery packs

• Portable power stations and power boxes

• RV and auxiliary power systems

• LED lighting battery assemblies

• Robotics and embedded power projects

• Replacement protection boards for compatible battery packs