1. Mainstream Battery Types
All Bluetooth earphones use polymer soft pouch lithium batteries (lithium polymer), with a few cylindrical lithium batteries. Features include slim design, customizable styling, and low self-discharge.
TWS single ear battery: capacity 30mAh~80mAh, ultra-thin square pouch;
Battery in the charging case: Capacity 300～600mAh, provides cyclic power replenishment to the earphones.
2. Core Usage Advantages
Small in size, high in energy density
The earphone cavity has an extremely small space, allowing the polymer lithium battery to be shaped into an irregular thin sheet, enabling power endurance in confined areas, which cannot be replaced by nickel-metal hydride or dry batteries.
Voltage adaptation
The nominal voltage is 3.7V, which is stepped down to 3.3V/1.8V by the power supply IC to power the Bluetooth chip and speaker. Charging stops at 4.2V, matching the charging circuit for earphones.
Fast chargeable with multiple cycles
Supports fast charging with low current, the charging case can fully charge the earphones in just a few minutes, with a cycle life of 300 to 500 times.
Low power consumption
The static leakage is minimal, and the earphones retain power even after being stored in the charging case for months, making them suitable for daily idle use.
3. Functional Supporting Applications
Standby and battery life
The single earbud relies on a small-capacity lithium battery to provide 4 to 8 hours of music playback, while the charging case offers an additional 3 to 5 charge cycles with its lithium battery, resulting in a total battery life of over 20 hours.
Bluetooth standby, noise-cancelling power supply
Active noise cancellation (ANC) and Bluetooth continuous signal transmission consume relatively high power, relying on stable and sustained current output from lithium batteries.
Protection integration
Each earbud lithium battery comes with a built-in PCB protection board: overcharge, over-discharge, overcurrent, and short-circuit protection to prevent earbud devices from swelling or overheating.
4. Development Trends
Miniature ultra-thin lithium battery: smaller size, higher capacity, enhances noise-canceling earphones' battery life;
Fast Charging Lithium Battery: Compatible with PD Fast Charging Dock;
Low-power lithium battery: compatible with Bluetooth 5.3 and LDAC high-definition decoding models.
