PW7126 + PW4406A×4 3-Cell Li-ion Battery Charge-Discharge Protection Board Solution, Continuous 6A, Overcurrent Protection 7A, with Balancing Circuit
Product Details PCB Design Suggestions
3S Li-ion Battery Protection Board — Code 8
Overview
This protection board is built around PWCHIP’s proprietary PW7126 protection IC, paired with four PW4406A MOSFETs. It provides complete overcharge, over-discharge, overcurrent, and short-circuit protection for 3S (three-cell series) lithium battery packs rated at 11.1 V nominal and 12.6 V fully charged. The board supports a continuous discharge current of 6 A, with an overcurrent protection threshold of approximately 7 A.
Specifications
|
Parameter |
Specification |
|
Battery Type |
3S (three-cell series Li-ion pack, 11.1 V nominal, 12.6 V fully charged) |
|
Continuous Discharge Current |
6 A |
|
Overcurrent Protection |
Approx. 7 A |
|
Protection IC |
PW7126 |
|
MOSFETs |
PW4406A × 4 |
|
MOSFET Package |
SOP8 |
|
Cell Balancing |
No |
|
Balance IC |
None |
|
Board Dimensions |
To be confirmed |
Main Control IC
The PW7126 is a dedicated protection IC designed for 3-cell lithium battery packs. It integrates overcharge, over-discharge, overcurrent, and short-circuit protection, and supports high-precision voltage detection.
Key Features
· Four PW4406A MOSFETs in parallel deliver 7 A overcurrent protection and 6 A continuous discharge.
· SOP8 MOSFET package offers a lower-cost alternative to TO252 solutions.
· PW7126 provides high-precision voltage detection.
· Optimized for medium-power 3S battery pack applications.
· Minimal external circuitry ensures excellent production consistency.
Circuit Schematic
Circuit Schematic
PCB Layout Photo
PCB Layout Photo
BOM (Bill of Materials)
|
Item |
Designator |
Part Number / Specification |
Qty |
|
1 |
CVC1 |
0603 1 µF / 16 V |
1 |
|
2 |
CVC2, CVC3 |
0603 0.1 µF / 16 V |
2 |
|
3 |
RSENSE |
2512 14 mΩ ±1% |
1 |
|
4 |
RVC1, RVC2, RVC3 |
0603 1 kΩ ±1% |
3 |
|
5 |
RVIN, RVM |
0603 2.21 kΩ ±1% |
2 |
|
6 |
U1 |
PW7126 SOP8 |
1 |
|
7 |
U2, U3, U4, U5 |
PW4406A SOP8 |
4 |
Typical Applications
Power tools, electric scooters, massage guns, electric gardening tools, and portable vacuum cleaners.
Wiring Instructions
Connect the battery cells according to the labels shown in the schematic. The charge/discharge terminals are P+ and P-.
Documentation & Technical Support
PWCHIP offers chip samples, technical documentation, and circuit design support. For more solutions or to request materials, please contact us at support@pwchip.com or reach out through our distributor network at https://www.pwchip.com/page/180.html.
