18650-1P2S 2200mAh 7.4V Lithium Ion Battery Pack

7.4V Lithium Ion Battery Pack Structural Overview

Engineers assemble the 7.4V lithium ion battery pack (18650 2S1P, 2200mAh class) using a series-connected dual-cell configuration. First, they select matched 18650 cylindrical cells with controlled internal resistance and capacity consistency. Then, they arrange two cells in series to achieve nominal voltage output while maintaining parallel-free compact structure. Meanwhile, technicians secure the cells inside a molded insulating frame to prevent mechanical movement and vibration displacement during handling. After module positioning, they prepare the pack for electrical interconnection and protective integration.

Cell Chemistry and Internal Material System

Manufacturers construct each 18650 cell using lithium metal oxide cathode coatings applied onto aluminum foil, while they form the anode using graphite-based carbon slurry coated onto copper foil substrates. In addition, they insert a microporous polyolefin separator between electrodes to maintain ionic conduction while preventing internal short circuits. Furthermore, they fill the cell with organic carbonate electrolyte containing lithium hexafluorophosphate, and they strictly control humidity exposure during filling and storage stages. Meanwhile, each cylindrical steel casing maintains sealed internal pressure stability throughout electrochemical operation.

Cell Matching and Pack Assembly Process

Technicians begin by screening individual cells for capacity, voltage consistency, and internal resistance alignment. Subsequently, they pair selected cells into a 2S configuration and weld nickel strips onto terminals using resistance welding equipment. After that, they integrate a protective circuit module (PCM/BMS) to manage overcharge, over-discharge, and overcurrent conditions. Meanwhile, they route output leads and insulate connection points using heat-shrink tubing and polymer spacers. Then, they perform structural fixation to ensure the assembly remains stable under vibration and mechanical stress.

Formation Cycling and Safety Standard Compliance

Engineers conduct controlled formation cycling to activate electrochemical interfaces and stabilize internal SEI layers. Then, they perform aging tests under regulated temperature conditions to evaluate voltage stability and impedance drift. Finally, quality teams execute electrical safety testing, insulation resistance measurement, and mechanical verification. Throughout production, the 7.4V lithium ion battery pack complies with IEC 62133 and UN38.3 standards, ensuring transport safety, structural reliability, and electrical consistency requirements.

Product Features

1. 🛠️ Customizable
   Customizable to meet customer requirements
2. ⚡ High Power
   Max. 20C discharge rate available
3. ⏱️ Long Cycle Life
   Meets long-term product usage needs
4. 🛡️ High Safety
   Passed comprehensive safety tests
5. 🔋 True Rated Capacity
   Matches the product design capacity
6. ⚛️ Multi-Chemistry Options
   Covers LCO, NCM, NCA and LFP systems
7. 🧰 Multi-Protection Mechanism
   Built-in protection board with overcharge, overdischarge, overcurrent and short-circuit protection

Product Application Areas

This product is suitable for a variety of portable and powered electronic devices, with typical applications including:

• Personal Care & Health: Electric Toothbrushes, Beauty Devices, Fitness Trackers, Medical Devices

• Smart Digital & Audio: Headphones, Speakers, Nebulizers, Toys, Lights

• Financial Payment & Office: POS Machines, USB Tokens, Portable Printers