701335 3.7V Small Lithium Battery Pack

The 3.7V small lithium battery pack combines small lithium-ion pouch cells with an accurate voltage control architecture. The pack is usually set up by the manufacturer in a single-cell (1S) format and thus has a nominal output of 3.7V and a full charge voltage of 4.2V. In the meantime, the discharge cut-off is carefully stabilized by engineers to avoid deep depletion and cell stress at about 2.75V. Consequently, there is consistency in electrical behavior when repeated charge cycles are used.

Cell Composition and Materials

Lithium cobalt oxide or mixed lithium-ion chemistry, which is mixed with aluminum-laminated polymer film, is often used in the pack. Besides this, internal electrodes are organized using layered coating technology, which enhances ionic conductivity and uniformity of the structure. The choice of copper and aluminum current collectors is aimed at minimizing internal resistance without affecting electron transfer. Moreover, insulating separators are placed between electrodes to avoid internal short circuits and provide structural safety in the case of vibration.

Structural Design and Assembly Process

In production, capacity and impedance matching of cells are done to minimize imbalance in the pack. This is followed by spot welding of nickel strips to create a stable electrical connection, which reduces thermal distortion. This is followed by the incorporation of a protection circuit module (PCM) to control overcharge, over-discharge, and overcurrent. Once assembled, technicians encapsulate it with a heat-shrink polymer or laminated casing, enhancing mechanical integrity and sealing performance. Moreover, quality control teams also conduct voltage calibration and load testing prior to final packaging.

Manufacturing Standards and Testing

Production follows internationally recognized safety and transport standards such as UN38.3, CE, RoHS, and The manufacturing is carried out in accordance with the internationally accepted safety and transport standards, including UN38.3, CE, RoHS, and UL compliance requirements. Additionally, manufacturers use constant-current/ constant-voltage (CC/CV) charging profiles, usually with a maximum charge voltage of 4.2V/cell. Testing of the cycles is also done under controlled temperatures to determine the retention of capacity over long-term use. Lastly, insulation resistance tests and short-circuit protection validation are performed to provide structural reliability and electrical stability during the product lifecycle.

Sample making, processing, and customization available

Product Features

• True Capacity: Consistent rated output with less long-term capacity fading.
• Low Self-Discharge: Stable power in long storage.
• High Discharge Performance: Low resistance guarantees 3A continuous output.
• Improved Safety: Multiple safeguards against overcharge, over-discharge, and short circuit.
• Compact Pouch Structure: Slim design accommodates slim electronic assemblies.
• OEM/ODM Available: Customizable tabs, leads, and terminal configurations.

Application Scenarios

We have lithium batteries that are popular in personal care, smart electronics, consumer devices, and medical equipment.

• Personal Care & Health: Fitness trackers, medical devices, electric toothbrushes.
• Smart Digital/Audio: Headphones, speakers, lights.
• Consumer & Entertainment: Toys, electronic products