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603535 665mAh Round Lithium Battery Factory
The 603535 3.7V 665mAh round lithium polymer battery is a rechargeable LiPo pouch cell designed for smart wearable devices, portable healthcare equipment, Bluetooth electronics, and compact IoT products. With its round-shaped structure, lightweight design, and stable discharge performance, this battery is ideal for products requiring compact installation and reliable portable power.
Manufactured by Lithotop, this round LiPo battery supports customized PCM/BMS solutions, connector configurations, and OEM battery assembly services for various rechargeable electronic applications.
Additional information
| Product Type | Round li-polymer battery |
|---|---|
| Model number | 603535 |
| Voltage (Nominal) | 3.7V |
| Capacity (Nominal) | 665mAh |
| Dimensions | 6*35*35mm |
| Constant Discharge Current | Typically 0.5C-1C |
| Working Temperature | charge: 0-45℃; discharge: -20-60℃ |
| Certification | ROHS |
Professional Grade A Lipo Battery Solutions
Delivering superior performance consistency and longer cycle life through automated cell matching technology designed for heavy-duty industrial applications.
The 603535 3.7V 665mAh round lithium polymer battery combines compact size with stable energy output, making it suitable for modern smart electronic products with limited internal installation space. Compared with traditional rectangular lithium batteries, the round pouch-cell structure provides better compatibility for circular or customized product housings.
Produced using high-quality lithium polymer materials and advanced manufacturing technology, this battery offers reliable charging and discharging performance, low internal resistance, and stable cycle life. The battery can also be customized with PCM protection boards, connectors, cables, labels, and packaging according to customer project requirements.
- Special Round Cell Structure
Ideal for compact products with circular or customized internal layouts. - 665mAh Stable Capacity
Provides reliable operating time for portable electronic applications. - Lightweight & Compact Design
Improves portability and internal space utilization. - Stable Charging & Discharging Performance
Ensures reliable voltage output and stable operation. - Rechargeable & Long Cycle Life
Supports repeated charging cycles with consistent performance. - Customizable Battery Solution
Supports customized PCM/BMS, connectors, cables, and labels. - Low Internal Resistance
Improves energy efficiency and reduces heat generation.
- Smart wearable devices
- Portable healthcare equipment
- Bluetooth electronic products
- Mini GPS systems
- Smart IoT devices
- Portable monitoring equipment
- Wireless communication products
- Smart sensors
- Rechargeable consumer electronics
- Compact portable devices
Round Lipo Battery
| Model | Voltage(V) | Capacity(mAh) | Cell Dimension(T*D)mm | Shape |
|---|---|---|---|---|
| 253027 | 3.7 | 150 | 2.5*30 | Round |
| 253027 | 3.8 | 155 | 2.5*30 | Round |
| 303027 | 3.7 | 180 | 3*30 | Round |
| 303028 | 3.8 | 185 | 3*30 | Round |
| 303535 | 3.8 | 305 | 3*35 | Round |
| 353535 | 3.7 | 365 | 3.5*35 | Round |
| 363027 | 3.8 | 235 | 3.6*30 | Round |
| 403535 | 3.8 | 425 | 4*35 | Round |
| 473027 | 3.8 | 335 | 4.7*30 | Round |
| 503535 | 3.7 | 525 | 5*35 | Round |
| 553535 | 3.7 | 580 | 5.5*35 | Round |
| 603535 | 3.7 | 665 | 6*35 | Round |
| 604543 | 3.7 | 1050 | 6*45 | Round |
| 753535 | 3.85 | 845 | 7.5*35 | Round |
| 755040 | 3.7 | 1500 | 7.5*50*40 | Round |
*Contact us for more Li-Po batteries or customize your special battery!
Customer Development Story
Discover how we helps global customers solve real-world battery challenges through customized lithium battery solutions.
01 – Smart Beauty Device Project from France
A French beauty technology company was developing a portable smart skincare device with a circular internal structure. During the prototype stage, they discovered that their original battery solution created uneven internal weight distribution, causing instability during handheld operation and reducing user experience.
The customer contacted Lithotop looking for a lightweight round lithium polymer battery with better structural compatibility. After reviewing the device layout and operating current requirements, Lithotop recommended the 603535 3.7V 665mAh round LiPo battery with customized connector direction and optimized cable routing.
During development, Lithotop adjusted the wire fixing structure and reduced connector thickness to improve assembly efficiency inside the compact housing.
Sample testing included charging cycle testing, handheld vibration testing, runtime evaluation, and assembly verification. After testing, the customer confirmed improved weight balance, more stable operation, and better product appearance consistency.
Before mass production, both teams confirmed connector specifications, sample consistency, aging performance, and packaging reliability. The final product successfully entered mass production and improved the overall user experience of the smart beauty device.
02 – Smart Retail Scanner Project from Italy
An Italian retail technology company was developing a compact wireless barcode scanner for mobile payment systems. Their previous battery supplier provided inconsistent material compliance documents, creating difficulties for European product approval and customer audits.
The customer approached Lithotop because of our experience supporting European compliance projects. After reviewing the scanner structure and power consumption requirements, Lithotop recommended the 603535 3.7V 665mAh round LiPo battery with reinforced insulation protection and optimized PCM settings.
During development, Lithotop improved cable fixing strength and optimized the battery protection structure to reduce movement during repeated scanning operations.
Sample testing included drop testing, charging stability testing, transportation simulation, and continuous scanning runtime evaluation. After testing, the customer confirmed improved operational stability and reduced assembly failure rates.
Before mass production, both teams confirmed incoming quality standards, connector specifications, packaging reliability, and aging performance. During mass production cooperation, Lithotop also supported the customer with RoHS certification documentation for European environmental compliance requirements.
The final product successfully entered large-scale production and helped the customer improve product approval efficiency and reduce compliance risks in the European retail market.
More Customer Cooperation Cases
Powering leading batteries across wearables, medical devices, IoT, and consumer electronics in 30+ countries..
Smart Bands
A European wearable technology company was developing a new smart fitness band with strict requirements for battery thickness, cycle life, and safety. Their device needed a lightweight LiPo battery that could fit into a compact wristband while support monitoring and Bluetooth connectivity.
Portable Medical Monitor
A startup company focusing on smart health products needed a flexible battery solution for their next-generation fitness monitoring wearable. The device design was slim and curved, requiring a customized LiPo battery with precise dimensions and stable charging performance.
Portable Translator
A customer from Asia was developing a portable AI translation device for travel and business communication. The product required a battery with stable voltage output, compact size, and long standby performance to support voice processing and wireless transmission.
Handling Precautions & Guidelines
Find answers to the most common questions about ordering, shipping, certifications, and working with lithotop as your battery partner.
Engineer’s will make inner BOM according to your confirmed samples. And our quality control teams continuously monitor the entire manufacturing process to ensure the each mass production is the same as samples.
LithoTop specializes in custom lithium battery solutions, including LiPo batteries, Li-ion battery packs, LiFePO4 batteries, high-rate drone batteries, curved batteries, ultra-thin batteries, and custom rechargeable battery packs for industrial and consumer applications.
LithoTop focuses on: Custom battery solutions for special applications, own developed PCB/PCM to help you with Competitive factory-direct pricing, Experience with difficult battery projects such as curved, ultra-thin, and high-discharge batteries. Long-term cooperation support for startups and established brands.
Yes. LithoTop provides fully customized battery solutions based on your device requirements, including voltage, capacity, discharge rate, dimensions, connector type, PCM/BMS protection, and special shapes such as curved or ultra-thin batteries.
Standard samples are usually available quickly about 3-7 days, while custom battery projects typically require evaluation, engineering confirmation, prototyping, and testing. The timeline depends on battery specifications, and certification requirements. Mass order is about 30 working days.
Depending on the product and project requirements, LithoTop batteries can support certifications including UN38.3, MSDS, CE, RoHS, IEC62133, UL , and other transportation or safety compliance documents.
MOQ depends on the battery model and customization level. Standard batteries may support lower quantities like 100pcs, while fully customized battery projects usually require a development MOQ. LithoTop supports both prototype projects and mass production orders.
LithoTop follows strict quality control procedures including: Incoming material inspection, Cell matching and grading Capacity, and voltage testing, Aging and performance tests, 100% Safety inspections before shipment. Quality consistency is critical for battery reliability and long-term cooperation.
Normally, we ship our batteries via DHL, UPS, FedEx, air freight, or sea , depending on order size, destination, and customer preference.
LithoTop is a professional lithium battery manufacturer with production experience in custom battery development and assembly. We provide direct factory support, engineering assistance, quality control, and customized battery solutions for global customers. We wecome you to visit our factory.
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Our Factory Insight
LithoTop operates advanced lithium battery manufacturing facilities equipped with automated production lines, precision testing equipment, and strict quality control systems. From cell selection to battery assembly and final inspection, every process is carefully managed to ensure stable performance, reliable quality, and high production efficiency. With experienced engineers and strong OEM/ODM capability, we provide customized battery solutions for customers worldwide.
Industry News Insight
Stay updated with the latest lithium battery industry news, product innovations, technology insights, and application trends from LithoTop. Explore expert articles, battery guides, and industry updates to learn more about custom lithium battery solutions, energy storage, UAV batteries, wearable device batteries, and advanced power technologies.
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