701335 3.7V Small Lithium Battery Pack

A 3.7V small lithium battery pack integrates lightweight lithium-ion pouch cells with precise voltage control architecture. Manufacturers typically configure the pack in a single-cell (1S) structure, and therefore it maintains a nominal output of 3.7V with a full charge threshold of 4.2V. Meanwhile, engineers carefully stabilize discharge cut-off near 2.75V to prevent deep depletion and cell stress. As a result, electrical behavior remains consistent across repeated charge cycles.

Cell Composition and Materials

The pack commonly uses lithium cobalt oxide or blended lithium-ion chemistry, combined with aluminum-laminated polymer film. In addition, internal electrodes are arranged through layered coating technology, which improves ionic conductivity and structural uniformity. Copper and aluminum current collectors are selected to reduce internal resistance while maintaining stable electron transfer. Furthermore, insulating separators are inserted between electrodes to prevent internal short circuits and ensure structural safety under vibration conditions.

Structural Design and Assembly Process

During production, cells are first matched by capacity and impedance to reduce imbalance within the pack. Next, spot welding connects nickel strips to form a secure electrical pathway, and this process minimizes thermal distortion. Subsequently, a protection circuit module (PCM) is integrated to manage overcharge, over-discharge, and over-current conditions. After assembly, technicians apply encapsulation using heat-shrunk polymer or laminated casing, which strengthens mechanical integrity and improves sealing performance. In addition, quality control teams perform voltage calibration and load testing before final packaging.

Manufacturing Standards and Testing

Production follows internationally recognized safety and transport standards such as UN38.3, CE, RoHS, and UL compliance requirements. Moreover, manufacturers apply constant-current/constant-voltage (CC/CV) charging profiles, typically limiting charge voltage at 4.2V per cell. Cycle testing is also conducted under controlled temperature conditions to evaluate capacity retention across long-term usage. Finally, insulation resistance tests and short-circuit protection validation are executed to ensure structural reliability and electrical stability throughout the product lifecycle.

Sample making, processing and customization available

Product Features

• 🔋 True Capacity: Reliable rated output with reduced long-term capacity fading.
• 🔌 Low Self-Discharge: Maintains stable power during long storage periods.
• ⚡ High Discharge Performance: Low resistance ensures stable 3A continuous output.
• 🛡️ Enhanced Safety: Multiple protections against overcharge, over-discharge, and short circuit.
• 📦 Compact Pouch Structure: Slim design fits compact electronic assemblies.
• ⚙️ OEM/ODM Available: Customizable tabs, leads, and terminal configurations.

Application Scenarios

Our lithium batteries are widely used in personal care, smart electronics, consumer devices, and medical equipment.

• Personal Care & Health: Electric toothbrushes, fitness trackers, medical devices
• Smart Digital & Audio: Headphones, speakers, lights
• Consumer & Entertainment: Toys, electronic products