The 3.7V 200mAh 08400 cylindrical LiPo battery is designed for compact electronic devices such as smart pens, digital writing devices, learning pens, and other portable applications. With a capacity of 200mAh, this rechargeable battery provides a stable and reliable power source for everyday device operation while maintaining a compact and lightweight form factor.
Featuring a cylindrical design, the 08400 battery can be easily integrated into space-constrained electronic devices. Its rechargeable design supports repeated use, making it a practical power solution for portable consumer electronics.
Built with lithium polymer battery technology, the 08400 provides stable voltage output and dependable performance. Optional PCM protection, connectors, wires, and other battery configurations can be customized according to specific application requirements. With its compact size, rechargeable design, and flexible customization options, the 08400 cylindrical LiPo battery is an ideal power solution for smart pens and other small electronic devices.
| Battery Type | Cylindrical LiPo Battery |
| Model Number | 08400 |
| Nominal Voltage | 3.7V |
| Nominal Capacity | 200mAh |
| Single Cell Energy | 0.74Wh |
| Cell Chemistry | LiCoO₂/ NCM (Customizable) |
| Pack Dimensions (Max) | 8.8(D) × 43.5(H) mm |
| Weight | Approx. 3.5g |
| Internal Impedance | ≤ 400mΩ |
| Shipment Voltage | 3.85–3.95V (Adjustable upon request) |
| Charging Voltage | 4.2V |
| Standard Charging Current | 0.2C |
| Max Charging Current | 1C |
| Discharge Cut-off Voltage | 3.0V |
| Standard Discharging Current | 0.2C / 3.0V |
| Max Discharging Current | 3.0C / 3.0V |
| Operating Temperature | Charge: 0–45 °C | Discharge: -20–60 °C |
| Dimensions Description |
W: 8.8 mm (Max) |
The 08400 3.7V 200mAh lithium battery is ideal for smart pens, digital pens, recording pens, learning pens, and other compact electronic writing devices, offering a compact size and rechargeable power solution.

Custom configurations, including PCM/BMS protection circuits, connectors, and cable options, are available to ensure safe integration into your specific product requirements.
All UNEMETECH rechargeable LiPo 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 partnered with UNEMETECH for our smart pen project. The 08400 battery’s compact cylindrical design, stable 3.7V output, and reliable 200mAh capacity have provided consistent power performance across our devices. CCC’s technical team offered prompt support and helped us optimize the battery integration to meet our smart pen’s size and performance requirements.”
— Product Development Manager, Smart Pen Manufacturer
UNEMETECH provides customized cylindrical LiPo battery solutions for smart pens, digital pens, learning pens, recording pens, and other compact electronic writing devices. Battery capacity, dimensions, PCM protection, connectors, wire lengths, labels, and battery pack assemblies can be customized according to your project requirements.
From prototype samples to volume production, our engineering team provides flexible battery customization, reliable manufacturing, and technical support to meet your specific smart pen battery requirements.