2S Li-ion Battery Protection Board (Code 15) — Product Introduction

Overview

This protection board is built around the PWCHIP PW7120 protection IC, paired with two PW4406A MOSFETs. It provides complete overcharge, over-discharge, overcurrent, and short-circuit protection for 2S lithium-ion battery packs (7.4 V nominal, 8.4 V fully charged). The continuous discharge current is 3 A, and the overcurrent protection threshold is approximately 7 A. The board also integrates the PW4584A boost charging IC, which supports 5 V / 2 A USB input and delivers up to 1 A charge current to the battery.

Specifications

Parameter	Specification
Battery Type	2S (2-series Li-ion, 7.4 V nominal, 8.4 V fully charged)
Continuous Discharge Current	3 A
Overcurrent Protection Threshold	Approx. 7 A
Protection IC	PW7120
MOSFETs	PW4406A × 2
MOSFET Package	SOP-8
Charging Input	USB 5 V / 2 A
Charging IC	PW4584A
Charging Topology	Boost charging
Battery-Side Charging Current	1 A

Key ICs

PW7120 is a dedicated 2-cell lithium-ion protection IC that integrates overcharge, over-discharge, overcurrent, and short-circuit protection. It requires minimal external components and offers low power consumption.

PW4584A is a switching boost charger suitable for 5 V USB input boosted to 8.4 V at 0.5 A–1 A. It integrates input overvoltage protection (OVP), shutting down charging when the input exceeds 6 V, and withstands input voltages up to 30 V.

Key Features

· Protection and charging combined on a single board for simplified charge/discharge management

· PW4584A boost charger: 5 V USB input boosted to 8.4 V

· 1 A battery charging current with integrated 6 V OVP shutdown

· 30 V input withstand to prevent damage from accidental high-voltage connection

· PW7120 protection IC plus two PW4406A MOSFETs for 7 A overcurrent protection

· Ideal for 2S battery packs that require USB charging

Schematic

Code 15 Schematic

PCB Photo

Code 15 PCB Photo

Typical Applications

Bluetooth speakers, portable LED lights, small fans, USB-charged products, wearable device charging docks.

Wiring Notes

Connect the battery as indicated on the schematic. The charge/discharge terminals are P+ and P-.

Documentation & Technical Support

We provide chip samples, technical documentation, and circuit design support. For more information or to request materials, please contact us at support@pwchip.com or reach an authorized distributor at https://www.pwchip.com/page/180.html.