Flat Lithium Battery Cell 502040 3.7v 400mAh Rechargeable Li-ion Polymer Battery Packs

Price Negotiable

Price: Negotiable

MOQ: 100pcs

Delivery Time: 7-10days

Brand: RESKY

Product Description

502040 3.7V 400mAh Rechargeable Li-ion Polymer Battery

High-performance 3.7V 400mAh 1.48Wh rechargeable Li-polymer battery cell designed for compact electronic devices requiring reliable power in limited space.

Technical Specifications

Battery Type	3.7V 400mAh Li-polymer
Charge Voltage	4.2V
Nominal Voltage	3.7V
Nominal Capacity	400mAh (0.2C Discharge)
Charge Current	Standard: 0.5C (200mA) Rapid: 1.0C (400mA)
Charging Method	0.5C CC to 4.2V, then CV until current ≤0.05C
Charging Time	Standard: ~2.75 hours Rapid: ~2 hours
Max Charge Current	1.0C (400mA)
Max Discharge Current	1.0C (400mA)
Discharge Cut-off Voltage	2.75V ±0.25V (0.2C)
Operating Temperature	Charging: 0°C to 45°C Discharging: 0°C to 45°C Storage: -10°C to 45°C
Dimensions	Length: 40±2mm Width: 20±0.5mm Thickness: 5±0.2mm
Cycle Life	≥500 cycles

Key Advantages

Miniaturization and Lightweighting: Ideal for space- and weight-sensitive applications like smart wearable devices and portable electronics
Design Flexibility: Can be manufactured in any shape and thickness with flexibility (maximum bending angle approximately 90 degrees)
Enhanced Safety: Gel electrolyte reduces leakage and explosion risks; internal problems indicated by bulging packaging
Capacity and Voltage Advantages: Higher capacity for same size compared to traditional lithium-ion batteries with improved system efficiency
Environmental Adaptability: Wide operating temperature range suitable for extreme environmental conditions

Structural & Safety Features

Electrode System: NCM/NCA ternary cathode material with graphite anode
Packaging: Aluminum-plastic composite film soft-pack with flexibility (bending radius ≥5mm)
Electrolyte: Polymer gel electrolyte with superior thermal stability and no leakage risk
Safety Protection: Built-in PCM module for overcharge, over-discharge, overcurrent, and short circuit protection
Drop Test Certified: Withstands 1-meter drops onto concrete without fire or leakage

Primary Applications

Smart Wearables & Children's Products

Entry-level smart bracelets and watches (1-3 day battery life)
Children's phone watches, smart toy watches, GPS bracelets
Mini heart rate monitors, pedometers, cycling speed sensors

Medical & Health Equipment

Portable diagnostic devices: electronic thermometers, oximeters, blood pressure monitors
Rehabilitation aids: mini massagers, physiotherapy devices, hearing aids

IoT & Smart Home Devices