2S Li-ion Battery Protection Board (Code 17) — Product Introduction

Overview

This protection board is based on the PWCHIP PW7120 protection IC and two PW4406A MOSFETs, providing comprehensive overcharge, over-discharge, overcurrent, and short-circuit protection for 2S lithium-ion battery packs (7.4 V nominal, 8.4 V fully charged). It delivers a 3 A continuous discharge current and an approximately 7 A overcurrent protection threshold. The integrated PW4000 buck-boost charger supports USB/DC inputs of 5 V / 2.2 A and 9 V / 2.2 A, with a battery-side charging current of 2.2 A.

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/DC 5 V / 2.2 A, 9 V / 2.2 A
Charging IC	PW4000
Charging Topology	Buck-boost charging
Battery-Side Charging Current	2.2 A

Key ICs

PW7120 is a dedicated 2-cell lithium-ion protection IC integrating overcharge, over-discharge, overcurrent, and short-circuit protection. It requires few external components and features low power consumption.

PW4000 is a synchronous switching buck-boost charger with conversion efficiency up to 95 %. It accepts 5 V–20 V input and regulates it to 8.4 V output at 0.5 A–2.4 A for charging 2S battery packs.

Key Features

· All-in-one protection and charging design

· PW4000 buck-boost charger supports 5 V–9 V wide-range input

· Compatible with 5 V USB and 9 V adapters, delivering 2.2 A charge current

· Synchronous switching topology with up to 95 % efficiency

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

· Ideal for 2S battery packs powered by multi-voltage adapters

Schematic

Code 17 Schematic

PCB Photo

Code 17 PCB Photo

Typical Applications

Power tools, portable vacuum cleaners, high-capacity power banks, electric scooters, in-vehicle devices.

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.