AJMRTC 14.8V 4S 30A 18650 Li-ion Battery BMS Protection Board, Lithium Battery Charge Discharge Balance PCB Module for 4 Series 18650 Battery Pack

AJMRTC 4S 30A BMS protection board is specially developed for 4-series 18650 lithium-ion battery packs with nominal voltage 14.8V. It monitors the voltage of each battery cell in real time during charging and discharging. Once any cell reaches the overcharge cutoff voltage, the board will cut off charging automatically to prevent battery swelling and damage. It also stops discharging when single cell voltage drops below over-discharge threshold to avoid irreversible capacity loss. The integrated passive balance circuit balances cell voltage differences while charging, which reduces inconsistency between batteries and prolongs the whole packs cycle life. It adopts high-performance power MOS chips and thick copper PCB layout, bringing low internal resistance to support 30A continuous current output and instant short-circuit lock-off protection. The onboard temperature thermistor detects board temperature; the BMS will shut down when overheating occurs. This module is widely used for DIY portable power stations, small electric motors, solar energy storage systems, LED driving power supplies, backup power and other 4S lithium battery equipment. Please follow the wiring sequence strictly when connecting battery cells; wrong wiring will burn the protection board.

Specifications

Brand: AJMRTC

Battery Configuration: 4S 4 Series 18650 Li-ion Battery

Nominal Voltage: 14.8V

Full Charge Voltage: 16.8V

Continuous Current: 30A

Protection Items: Overcharge, Over-Discharge, Over-Current, Short Circuit, Over Temperature

Balance Function: Passive Cell Balance

Balance Current: About 40mA

PCB Material: FR-4, Thick Copper Layout

Temperature Detection: NTC Thermistor Included

Cell Type: For Li-ion 18650 Battery (Not for LiFePO4)

Application: DIY Power Station, Electric Motor, Solar Storage, LED Power Supply, Backup Power

Package Quantity: 1 Pcs

Note: Strictly follow B-, B1, B2, B3, B4 wiring order; reverse connection will damage the board