2S Li-ion Battery Protection Board (Code 24) — Product Introduction

Overview

This protection board features the PWCHIP PW7120 protection IC and two PW4406A MOSFETs, delivering 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 integrated PW4252 synchronous boost charger supports 5 V / 2.4 A USB input and provides up to 1.2 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 / 2.4 A
Charging IC	PW4252
Charging Topology	Synchronous boost charging
Battery-Side Charging Current	1.2 A

Key ICs

PW7120 is a dedicated 2-cell lithium-ion protection IC integrating overcharge, over-discharge, overcurrent, and short-circuit protection. Its peripheral circuit is simple and its power consumption is low.

PW4252 is a synchronous switching boost charger with conversion efficiency up to 95 %. It is suitable for 5 V USB input boosted to 8.4 V at 0.4 A–1.2 A. The IC integrates input OVP, disabling charging when the input exceeds 6 V, and supports input voltages up to 18 V.

Key Features

· Protection and charging combined on a single board

· PW4252 synchronous boost charging with up to 95 % efficiency

· 5 V USB input boosted to 8.4 V, delivering 1.2 A charge current

· Integrated 6 V OVP shutdown and 18 V input withstand

· Higher efficiency and lower heat generation than the PW4584A solution

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

Schematic

Code 24 Schematic

PCB Photo

Code 24 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.