Product Description

The 4S 40A Lithium‑Ion Battery Protection Board is a high‑performance BMS (Battery Management System) designed to safeguard your battery pack from overcharge, over‑discharge, short circuit, and overcurrent conditions. It continuously monitors voltage and current across four cells connected in series, automatically disconnecting the load or charger when unsafe conditions occur.

Ideal for DIY electronics, robotics, Arduino/Raspberry Pi projects, 3D printers, and quadcopters, this board ensures safe operation and extends battery life. Compatible with 18650 lithium‑ion cells (3.6 V – 3.7 V nominal), it provides a total pack voltage of approximately 14.8 V nominal and 16.8 V maximum.

Key Features

·         Comprehensive Protection – Overcharge, over‑discharge, short‑circuit, and overcurrent safeguards

·         High Current Capacity – Supports up to 40 A continuous load

·         Automatic Cut‑off – Disconnects battery during unsafe conditions

·         Voltage Balancing – Maintains uniform charge across all cells

·         Compact Design – Easy to integrate into battery packs and DIY builds

Technical Specifications