Case study of smart glasses using Pogo Pin magnetic charging cable

I. Design background and market demand

As a core category of wearable devices, smart glasses need to take into account compactness, reliability and user experience in terms of charging solutions. Traditional Type-C interfaces have problems such as large space occupation, easy wear and poor waterproofness, while Pogo Pin magnetic charging cables have become the mainstream choice in the industry with their characteristics of zero plug-in force, automatic adsorption and high sealing. Manufacturers represented by Cnomax company have provided customized solutions for brands such as Huawei, Xiaomi and Thunderbird, promoting the large-scale application of Pogo Pin in the field of smart glasses.

II. Appearance design: fusion of concealment and aesthetics

Innovation in contact layout
Pogo Pin contacts are usually hidden in non-exposed areas such as temples or nose pads. For example, Thunderbird V3 smart glasses integrate 18pin charging contacts at the end of the right temple, and achieve visual integration through bright paint process. Huawei and Xiaomi's AI glasses use a one-to-two magnetic cable design. When charging, the two contacts are connected to the left and right temples respectively to ensure symmetrical beauty.
Optimization of magnetic structure
The number and position of magnetic parts directly affect the alignment accuracy. A patented solution sets three magnetic parts + dual contacts on the nose pad, and three magnetic parts are configured at the corresponding position of the charging box. The magnetic field is guided to achieve ±0.1mm level precise docking, while increasing the adsorption force to prevent loosening. This design not only ensures charging stability, but also avoids the exposure of contacts to damage the overall lines.
Lightweight and adaptability

The thickness of the Pogo Pin interface is only 0.5-1mm, which is more than 60% thinner than Type-C, and significantly reduces the thickness of the temples (such as the thinnest part of the Huawei Eyewear II temples is only 4mm). Some products also support charging in any folding direction. For example, the charging box of Thunderbird V3 adopts a dual contact layout, and the temples can be automatically adsorbed and charged regardless of being folded left or right, which improves the flexibility of use.

III. Functional characteristics: both efficiency and safety

Dual compatibility of charging and data transmission
Pogo Pin realizes power + signal composite transmission through multi-pin design. For example, the 18-pin magnetic cable of Thunderbird V3 not only supports 5V/1A charging, but also transmits sensor data such as gyroscopes and cameras to meet the needs of firmware upgrades and real-time image transmission. The Cnomax company solution adopts a bevel + ball structure, adding steel balls to the needle tube to reduce the spring current load, which can stably support 5-30A high current, and the charging speed is 30% higher than the traditional solution.
Enhanced protection performance

Waterproof and dustproof: The Pogo Pin magnetic interface achieves IP67 protection through a silicone seal and a metal shield, and can work normally after being immersed in 1 meter of water for 30 minutes (such as Huawei Eyewear II).

Anti-external impact: The magnetic connection automatically disconnects when encountering a pulling force of more than 10N to prevent the glasses from falling and being damaged. At the same time, the gold-plated contacts (thickness 3-5μm) can withstand 50,000 plug-ins and unplugs without obvious wear.
Enhanced intelligent interaction
Some high-end products combine Pogo Pin with NFC. For example, a Huawei smart glasses triggers the fast pairing mode through the magnetic charging cable, completes the Bluetooth connection with the mobile phone within 1 second, and supports real-time display of charging status.

IV. Technical implementation: precision manufacturing and material innovation

Contact structure design
Pogo Pin adopts the elastic contact solution of spring pin + needle tube. The spring compression stroke is usually 0.8-1.2mm to ensure stable connection when the glasses are shaking. To improve conductivity, the thickness of the gold plating layer on the contact surface needs to be controlled at 3-5μm, which not only reduces the contact resistance (<50mΩ), but also meets the 48-hour salt spray test without corrosion.
Magnetic component selection
The magnetic field strength of the neodymium iron boron magnet (N42 level) needs to accurately match the contact spacing. For example, the magnet spacing of the Thunderbird V3 charging box is 8mm, and the adsorption force is designed to be 0.5N, which can ensure a stable connection and facilitate one-handed disassembly. Some manufacturers also optimize the arrangement of magnetic poles (such as the middle N pole and the two S poles) to prevent abnormal data transmission due to magnetic field interference during charging.
Circuit protection mechanism
To prevent overvoltage and overcurrent from damaging the device, the Pogo Pin charging cable has built-in TVS tube + fuse dual protection. For example, the charging contact circuit of Thunderbird V3 integrates a TVS tube with silk screen T18, which can withstand ±15kV electrostatic shock, and the charging current is dynamically adjusted through the BQ25600 power management chip.

V. Typical case analysis

Thunderbird V3 smart shooting glasses

Design highlights: 18pin magnetic cable realizes synchronization of charging and 4K video transmission, the contacts at the end of the temples are gold-plated, and the charging box supports docking in any folding direction.
Performance parameters: charging power 5W, IP54 dust and water resistance, single battery life 4 hours, and the charging box provides an additional 12 hours of battery life.
User scenarios: Suitable for outdoor shooting, industrial inspection and other scenes that require frequent charging. Magnetic charging avoids the difficulty of plugging and unplugging when wearing gloves.
HUAWEI X GENTLE MONSTER Eyewear II
Design highlights: There is no physical interface on the temples, and invisible charging is achieved through magnetic charging cables. IP67 waterproof can cope with rain and sweat.
Innovative functions: Trigger NFC fast pairing during charging, support call noise reduction and spatial audio, and automatically switch to "cinema mode" after magnetic connection.
Market positioning: Focus on the integration of fashion and technology, and the target users are business people and fashion lovers.

Xiaomi AI glasses

Design highlights: One-to-two magnetic cables charge the left and right temples at the same time, and the contacts are hidden on the inside of the temples, supporting blind operation.
Technological breakthrough: Using Cnomax company's multi-pin multiplexing technology, the same contact can switch charging/data transmission mode according to voltage changes, reducing hardware costs by 15%.
User pain points: Solve the problems of easy entanglement and easy damage of traditional glasses charging cables, suitable for students and office workers.

VI. Industry Challenges and Future Trends

Existing Problems
Contact contamination: Dust or sweat may cause poor contact after long-term use, and regular cleaning is required.
Cost Control: The cost of high-precision Pogo Pin components is 30%-50% higher than that of Type-C interfaces, which limits the application of mid- and low-end products.
Compatibility: The magnetic specifications of different brands are not uniform, and users need special charging cables, which affects the experience.
Technical Innovation Direction
Wireless + Magnetic Fusion: Some manufacturers explore combining Pogo Pin with Qi wireless charging. For example, a patented solution achieves dynamic wireless charging through magnetic positioning, and the charging efficiency is increased to more than 70%.
Self-cleaning technology: Super-hydrophobic coating or micro-vibration motor is used to automatically remove impurities on the contact surface during charging to extend the service life.
Standardization Promotion: Industry associations are promoting the unified protocol and physical specifications of Pogo Pin magnetic interfaces, which are expected to be universal across brands in the future.

Pogo Pin magnetic charging cables have become the optimal solution for smart glasses charging solutions through structural innovation, material upgrades and functional integration. Its advantages in concealment, protection, and interactivity not only meet users' needs for portability and durability, but also promote the design innovation of wearable devices. With the iteration of technology and the reduction of costs, Pogo Pin is expected to become more popular and deeply integrated with wireless charging, smart sensing and other technologies, injecting new momentum into the development of smart glasses.

Author: Jerry_shi,2025-07-11