The 3.7V 500mAh Lithium Polymer Battery 502740 is a high-performance, rechargeable power source designed specifically for hearing aid charging cases. With its compact size and reliable performance, this battery ensures efficient charging and long-lasting power for your hearing aids. The 502740 model provides the perfect balance of capacity and voltage, offering a stable and durable solution for keeping your hearing aids charged and ready for use throughout the day.
| Battery Type | Lithium Polymer Battery |
| Model Number | UNM 502740 |
| Nominal Voltage | 3.7V |
| Capacity | 500mAh (Minimum) | 530mAh (Typical) |
| Cell Energy | 1.85Wh |
| Cell Chemistry | LiCoO₂ / NCM (Customizable) |
| Cell Dimensions (Max) | 4.8 × 26.5 × 37.5 mm |
| Pack Dimensions (Max) | 5.0 × 27.0 × 40.0 mm |
| Weight | Approx. 11.0g |
| Battery Pack Internal Impedance | ≤ 100 mΩ |
| Shipment Voltage | 3.85–4.00V (Adjustable upon request) |
| Max Charge Voltage | 4.2V |
| Standard Charge Current | 0.2C (100mA) to 4.2V, CCCV Mode |
| Max Charge Current | 1.0C (500mA) | Customizable |
| Discharge Cut-off Voltage | 3.0V |
| Standard Discharge Current | 0.2C (100mA) |
| Max Continuous Discharge Current | 1.0C (500mA) | Customizable |
| Operating Temperature | Charge: 0–45 °C | Discharge: -20–60 °C |
| Max. Cell Dimensions: 4.8 × 26.5 × 37.5mm | Plug wire: Molex78172-3P | UL3302AWG28 | 30±3mm (Adjustable) |
| Max. Pack Dimensions: 5.0 × 27.0 × 40.0mm | PCM Protection: S8261DAA-M6T1U+PW8205 |

The 3.7V 500mAh Lithium Polymer Battery 502740 is designed for use in hearing aid charging cases, providing reliable, long-lasting power to keep your hearing aids charged and ready for use at all times. This LiPo Battery is ideal for:

Custom configurations, including PCM/BMS protection circuits, connectors, and cable options, are available to ensure safe integration into your specific product requirements.
All UNEMETECH lithium polymer batteries undergo strict quality control and comply with international safety & transportation standards, ensuring safe and reliable performance worldwide.
Depending on project requirements and target market regulations, we can provide certification documents such as CB, IEC 62133, UN38.3, MSDS, KC, PSE, BSMI, UL, RCM, CE, REACH, and RoHs 2.0 test reports, and other compliance documentation as required.

“We’ve integrated the 502740 lithium polymer battery into our hearing aid charging cases, and the results have been outstanding. The battery's consistent performance, long cycle life, and reliable power delivery have resolved our previous charging issues. The UNEMETECH team was incredibly responsive, providing excellent support to fine-tune the battery’s integration and ensure seamless operation with our devices. This battery has been a game-changer for us—highly recommended!”
— Product Development Manager, Hearing Aid Charging Case Manufacturer
UNEMETECH provides customized LiPo battery solutions for medical devices, wearable devices, portable electronics, IoT equipment, and other battery-powered applications. Optional PCM/BMS protection circuits, connectors, wire lengths, labels, and battery pack assemblies can be configured according to your project requirements.
Whether you require prototype samples or volume production, our engineering team can support your battery customization needs with reliable manufacturing and technical assistance.