Custom Curved Lipo Battery Solves Space Challenge in Smart Rings

Client Requirements for Smart Ring Curved LiPo Battery

High Energy Density

The battery must deliver high energy density despite its small size, enabling the smart ring to store sufficient power within a compact form factor.

Lightweight and Compact Design

The battery should be lightweight and carefully designed to fit the ring’s internal and external structure, ensuring seamless integration without affecting comfort or aesthetics.

Long Battery Life

The battery must support extended usage time to minimize the need for frequent charging, meeting the performance expectations of end-users.

Safety Compliance

Given the battery’s proximity to the user’s skin, it must adhere to strict safety standards to prevent overheating, short circuits, or other hazards, ensuring safe operation at all times.

In conslusion, the battery should have the highest possible capacity while being as thin and compact as possible.

From Challenge to Reality: Our Curved Lipo Battery for Smart Ring

Our Curved Lithium Polymer Battery Battery Features:

Ultra-Compact & Lightweight: Exceptionally small and thin form factor (max 1.8mm thick, 22mm long) with an approximate weight of only 0.5g, ideal for highly space-constrained applications.
Miniature Capacity: Provides a 17mAh typical capacity at a standard 3.7V voltage, suitable for low-power, long-term standby devices.
High Energy & Voltage — Strong performance with high working voltage and excellent energy density.
Robust Safety: Complies with GB/T 31241-2022 and passes standard safety tests including overcharge, short-circuit, crush, and impact.
Wide Temperature Range: Can be discharged in temperatures from -20°C to 60°C, offering reliable operation in various environments.
Long Cycle Life: Rated 500 cycles to 80% of initial capacity, ensuring a stable and durable service life.

Step 1: Enhancing Battery Energy Density

The energy density of a battery depends on several factors, including voltage, capacity, volume, and weight. Since the voltage is fixed for smart ring applications, we focus on optimizing capacity and volume to achieve higher energy density.

Energy Density Formulas:

Gravimetric Energy Density (per unit mass):

Volumetric Energy Density (per unit volume):

Where:

= nominal voltage of the battery
= battery capacity
= battery weight
= battery volume

Our Solution:

High-Capacity Materials: By selecting advanced electrode materials with superior capacity, we can store more energy within the same battery size.
Stacking (Lamination) Technique: To maximize the utilization of available space, we use a precise stacking process that efficiently arranges the electrode layers, increasing the effective volume without enlarging the battery footprint.

This approach allows the battery to deliver maximum power in a compact form factor, perfectly suited for space-constrained smart rings.

Step 2: Overcoming Lightweight and Compact Design Challenges

To fit the smart ring’s limited space, we designed a custom curved battery using a precise workflow:

3D Scanning & Modeling: High-resolution scans capture the ring’s inner curvature, and a 3D battery model is created to match it perfectly.
Ultra-Thin Profile: Only 1.7 mm thick, using stacked electrodes to eliminate wasted space.
Flexible, Lightweight Materials: An ultra-thin aluminum-plastic composite film allows shaping to the curve while keeping the battery light and durable.

This combination ensures the battery is compact, lightweight, and perfectly fitted for comfortable wearable use.

Step 3: Ensuring Long Battery Life

Extended Usage per Charge: High energy density allows the battery to power the device longer on a single charge.
Prolonged Cycle Life: Our optimized Battery Management System (BMS) combined with rigorous cell selection ensures that the battery retains over 80% of its original capacity after 500+ charge-discharge cycles, significantly extending the product’s usable life.

This approach guarantees that the smart ring delivers reliable performance and longevity, meeting both user convenience and product durability requirements.

Step 4: Ensuring Safety and Compliance

Safety is paramount for smart ring batteries, and we implement multiple layers of protection to earn customer trust:

Built-in Protection Circuits: Dedicated IC circuits prevent overcharge, over-discharge, and short circuits.
Reinforced Separator Materials: High-strength separators reduce the risk of internal short circuits.
Durable Casing: High-strength aluminum-plastic film provides excellent puncture resistance and corrosion protection.
International Certifications: The battery meets UL, CE, and RoHS standards, ensuring safe wearable use.

Conclusion

This collaboration represents a successful example of a high-performance custom battery solution for wearable devices, particularly space-constrained smart rings. The project demonstrates how curved LiPo battery design, precision engineering, and advanced materials can overcome size, comfort, longevity, and safety challenges.

If your product also faces internal space limitations and requires a high-performance, safe, custom battery solution, contact us today. Our engineering team is ready to provide tailored support and bring your wearable device to life.

Email: info@landazzle.com
Whatsapp: +8618938252128