In recent years, as the TWS earbuds industry has grown rapidly, one very practical issue has become more and more obvious:
Earbuds are getting smaller, but they are packing in more and more features, and battery life is under increasing pressure. From a manufacturing point of view, the current mainstream battery solutions for TWS earbuds can be divided into two types: coin cell batteries and prismatic pouch batteries.
However, both solutions have clear structural limitations.
As product designs continue to become more extreme and compact, custom battery solutions are becoming a more common and practical choice in the industry.
Common Battery Solutions for TWS Earbuds
Most TWS earbuds on the market today use either coin cell batteries or prismatic pouch batteries.
These two types have become mainstream mainly because they are highly standardized, low in mass-production cost, and supported by a mature supply chain. For entry-level and mid-range high-volume models, they offer clear advantages such as low initial investment and fast development.
However, both battery types also have their limitations.
Coin Cell Batteries
Coin cell batteries were very common in early TWS earbuds, especially in ultra-light and ultra-compact designs.
Their advantages are quite straightforward:
- Small size and high standardization
- Relatively low and controllable cost
- Mature supply chain with stable delivery
However, coin cell batteries also have clear limitations:
1. Low energy density ceiling
The coin cell structure uses a rigid metal casing, which limits internal space utilization. As a result, it is difficult to further increase battery capacity.
2. Fixed shape, not flexible for product design
The internal space of TWS earbuds is irregular, but coin cells are always round. This means the product design often has to be adjusted to fit the battery, rather than the other way around.
3. Average discharge performance
Especially during high-volume playback or when noise cancellation is turned on, the peak current capability is limited, which can lead to voltage drops.
Prismatic Pouch Batteries
As TWS earbuds have evolved with more advanced features, pouch batteries have gradually become the mainstream choice.
Compared with coin cell batteries, their advantages are quite clear:
- Higher energy density
- Partially customizable shape
- Better suited for irregular internal spaces
- Lighter weight
However, in real mass production, pouch batteries are not a “perfect solution”.
1. Fixed shape, still limited space utilization
Although pouch batteries are rectangular, the internal space of TWS earbuds is often irregular, curved, or even highly customized. As a result, the battery cannot fully match the cavity structure, leaving unused space.
2. Limited adaptability
The “flexibility” of pouch batteries is only relative to metal-cased batteries. In essence, they are still fixed-shape structures.
For new earphone designs such as open-ear clip-on styles or curved in-ear designs, rectangular pouch batteries often cannot fully fit the internal layout.
3. Mechanical strength limitations
Pouch batteries use an aluminum-plastic film structure. Compared with metal-cased coin cells, they are weaker in terms of compression and impact resistance.
Under long-term use or structural pressure, there is a higher risk of swelling or leakage. This is also one of the reasons why some earphones experience battery performance degradation over time.
Why Custom Batteries Solve the Limitations of Traditional Solutions
Compared with coin cell batteries and prismatic pouch batteries, the core value of custom batteries is not just “more flexibility”, but redefining the relationship between the battery and the internal cavity at a structural level.
Maximum use of internal space, battery life improves by 10%–30%
This is the most direct advantage of custom batteries.
Instead of forcing a standard battery into the space, we design the battery based on the real internal structure of the earphone, including:
- Curved shapes
- L-shaped structures
- Semi-circular or irregular fitted designs
Through electrode cutting, stacking processes, and optimized aluminum-plastic film packaging, the battery can be made to fit the available space as much as possible.
As a result:
Space utilization can reach over 95%, significantly higher than standard solutions.
For TWS products, where competition happens at the millimeter level, this improvement often directly leads to:
- Higher capacity
- Longer battery life
- Or smaller device size
Better fit with internal structure, improved comfort and sound quality
The problem with traditional batteries is that they “take up space”, while custom batteries are designed to “blend into the structure”.
By fully matching the internal cavity design, two key improvements can be achieved:
1. Better wearing comfort
The battery does not create hard pressure points or uneven thickness. This results in a more balanced weight distribution and a lighter, more stable wearing experience.
2. No negative impact on acoustic design
The battery can be arranged around the acoustic components, leaving enough space for the sound chamber. This helps avoid:
- Muffled sound
- Weak bass performance
- Internal space compression
Simply put, the battery fills the space, but does not interfere with the sound system.
High adaptability to different TWS form factors, lower structural risk
Today, TWS earbuds come in many different shapes, such as:
- In-ear designs
- Semi in-ear designs
- Open-ear clip-on designs
- Irregular structural designs
Standard coin cell or prismatic pouch batteries are no longer suitable for many of these new formats.
Custom batteries, however, are designed based on the structure itself. For example:
- Clip-on earphones: C-shaped / curved batteries
- In-ear models: ultra-thin custom-shaped batteries
- Large over-ear headphones: high-capacity custom pouch batteries
This approach not only improves compatibility, but also:
Improves overall production yield
Reduces assembly difficulty
Lowers structural compression risk
Conclusion
From coin cell batteries to prismatic pouch batteries, the evolution of battery solutions for TWS earbuds has essentially been a series of compromises between space efficiency and user experience.
However, as product designs become more diverse, smaller in size, and more function-rich, standardized battery solutions are no longer sufficient to support the next stage of product competition.
What truly creates differentiation is no longer just the chipset, algorithms, or exterior design, but whether the battery can become a true part of the product’s structural design.
The value of custom batteries is not simply “switching to a different battery type.”
It lies in using custom shapes, stacked cell processes, and system-level integration limited space reusable energy within a limited space—while still ensuring wearing comfort, sound quality, and long-term reliability.
For TWS earbuds brands and R&D teams, the battery solution itself has become a core part of the product experience, not a passive, off-the-shelf component.
Contact Us for a TWS Earbuds Battery Solution Designed for Your Product
If you are developing or upgrading TWS earbuds and facing challenges such as:
- Limited internal space with little room to improve battery life
- New product designs that cannot fit standard batteries
- Concerns about trade-offs between sound quality, comfort, and battery design
- The need to improve competitiveness without increasing product size
We welcome you to contact us directly.
We are a manufacturer specializing in custom lithium battery solutions, with proven experience in custom-shaped batteries for wearable devices.
Email: info@landazzle.com
Whatsapp: +8618938252128
