Home / Applications / Heated Insoles Battery

Heated Insoles Battery Application

In the harsh winter season, the demand for foot warmth is steadily increasing among outdoor workers, skiing enthusiasts, and individuals with rheumatoid arthritis. Traditional methods of keeping warm often fall short in providing both flexibility and long-lasting heat, which has led to the rise of wearable heating devices—most notably, heated insoles. These insoles use built-in heating elements and temperature control systems to deliver adjustable and continuous warmth to the user. The key component that powers this functionality is the “heated insole battery,” which is cleverly concealed within the insole or the upper part of the shoe.
Custom Lithium Battery
irayenergy-product-applications

Heated Insoles Battery Guide | How to Choose Battery for Heated Insoles？

A high-quality heated insole battery not only determines the duration and maximum temperature of heating but also affects overall comfort, safety, and wearability. However, in actual use, users often face issues such as short battery life, rapid power loss in low temperatures, bulky size, and non-replaceable designs—factors that significantly hinder the user experience. At the same time, manufacturers developing heated insoles frequently encounter challenges due to limitations in battery thickness, flexibility, waterproof encapsulation, and power interface standards, leading to extended development cycles and poor compatibility. In the following sections, the editor from Iray Energy will guide you through an in-depth understanding of heated insole batteries, their core requirements, mainstream battery types and performance comparisons, along with other important usage considerations.
1、What Is a Heated Insole Battery?
A heated insole battery refers to a rechargeable power unit specifically designed to supply energy to heated insole systems. It typically features a compact and slim design, embedded within or attached externally to the insole structure, providing stable power to internal heating wires or carbon fiber heating films. These batteries are predominantly 3.7V lithium-ion or lithium-polymer types. Some high-end models also integrate smart components such as temperature control chips, overheating protection circuits, and wireless control modules, enabling multi-level temperature adjustment, timed heating, and remote operation.
The capacity of a heated insole battery generally ranges from 1000mAh to 3000mAh, offering a runtime of approximately 2 to 8 hours depending on the heating power and setting level. Based on the insole design and application needs, the battery can be embedded inside the insole itself or mounted externally on the shoe upper or strap, connected to the heating module via cable or wireless transmission. It is not only the core of the insole’s heating function but also a critical factor in the overall user experience. The battery’s performance directly affects whether the product can operate properly in cold environments, whether it is lightweight enough, if it poses any safety risks, and whether it is convenient to replace or maintain.
2、What Are the Basic Requirements for Heated Insole Batteries?
Similar to the demands of heated clothing, the application scenarios of heated insoles require batteries to meet three essential criteria simultaneously: compact size, high performance, and high safety. Below are the core industry requirements:
1)Stable Output in Low-Temperature Environments:
Heated insoles are mostly used in extremely cold conditions below –10°C, especially in countries like Russia. Therefore, the battery must have excellent low-temperature discharge capabilities, maintaining at least 70% output capacity at –20°C to ensure reliable performance in harsh winter climates.
2)Long Battery Life with Lightweight Design:
Users typically expect their insoles to provide continuous heating for an entire outdoor activity or work session (4–8 hours), without compromising the comfort of the shoes. This means the battery needs to achieve high energy density while remaining light and thin to preserve flexibility and wearability.
3)High Safety Standards:
As the foot is a load-bearing part of the body, batteries used in insoles are subject to compression, deformation, and humid environments. As such, they must feature multiple protection mechanisms, including overcharge and over-discharge protection, temperature control, short-circuit protection, and IPX-rated waterproofing to ensure safe operation.
4)Modular Compatibility and Structural Adaptability:
Given the diversity in insole manufacturers and product dimensions, batteries should support multi-spec customization, including precise thickness control (≤6mm), flexible packaging, and standardized connectors, allowing seamless integration with various heating elements.
5)Reliable Cycle Life:
The battery should retain at least 80% of its capacity after 300–500 charge-discharge cycles, ensuring durability for long-term and seasonal use, while reducing the need for frequent replacements or early product retirement.
3、Common Types of Heated Insole Batteries and Their Comparison
There are various types of batteries available on the market for heated insoles, including alkaline batteries, nickel-metal hydride (NiMH) batteries, lithium-ion batteries, and lithium-polymer batteries. Each type comes with its own advantages and disadvantages and is suited to different application scenarios. When selecting a battery, manufacturers often have to balance multiple factors such as size, voltage, low-temperature performance, safety, and cost. Below is a detailed comparison of the types of heated insole batteries, including their pros and cons and typical applications:
Battery Type Advantages Disadvantages Typical Application Scenarios
Alkaline Battery (AA)
Low cost
Short heating time, bulky size, heavy weight
Basic heated insoles, disposable warming pads
Nickel-Metal Hydride (NiMH)
Safe and stable, good overcharge resistance
Large size, low energy density, poor discharge platform
Older multifunctional insoles, heated slippers
Lithium-Ion Battery (Cylindrical)
Good cell consistency
Bulky size
Outdoor boots, heated shoes with external battery packs
Lithium-Polymer Battery (Soft Pack)
Customizable size, high energy density
Relatively higher cost
High-end heated insoles, smart warming insoles
4、Why Are Lithium-Ion Batteries Chosen as the Power Source for Heated Insoles?

Lithium-ion batteries have become the dominant power source in the heated insole industry primarily due to their advantages across several key performance indicators:

1)High Energy Density:
Lithium batteries offer significantly higher capacity per unit weight or volume compared to NiMH or alkaline batteries, enabling longer runtime within limited space—an especially critical factor for wearable devices.
2)Ultra-Thin and Flexible Design:
Lithium-polymer batteries support flexible packaging and can be made as thin as 1–12mm, allowing them to be easily embedded into insoles without compromising user comfort. This level of thinness and flexibility is unattainable with cylindrical lithium-ion batteries in steel casings.
3)Excellent Low-Temperature Performance:
With optimized electrolyte formulations and advanced cell manufacturing techniques, lithium-ion batteries can maintain normal output at temperatures as low as –20°C. In contrast, other battery types typically suffer from a sharp increase in internal resistance or a drastic drop in capacity under cold conditions.
4)Support for Smart Control Systems:
Lithium batteries can seamlessly integrate with temperature control ICs, Bluetooth modules, NTC thermistors, and more, enabling features such as multi-level heating adjustment, smart shutdown, and mobile app control.
5)Superior Cycle Life:
High-quality lithium batteries maintain good performance even after 500 full charge-discharge cycles, allowing for consistent use over 1–2 winter seasons without noticeable degradation—far surpassing other battery types that require more frequent replacement.
6)Environmentally Friendly and Aligned with Industry Trends:
With global regulations increasingly restricting the use of plastics and mercury, lithium batteries stand out as a more sustainable option due to their recyclability and lower environmental impact.
5、How to Choose the Right Battery Supplier for Heated Insoles?

Although heated insoles are a type of small consumer electronic product, they place exceptionally high demands on battery suppliers in terms of performance, safety, structural compatibility, and delivery assurance. Selecting a reliable battery supplier is not only the foundation for ensuring product quality but also a key factor in whether a brand can stand out in the market. The following are the essential factors to consider when selecting a supplier:

1)Does the supplier have the capability to develop and customize lithium batteries in various sizes?
Heated insoles typically require very specific battery dimensions. Off-the-shelf battery cells often cannot be directly applied, so it is crucial for the supplier to have capabilities in customizing soft-pack lithium batteries, cell matching, and PCM design. They should also be able to handle detailed structural adjustments, tab orientation, and low-temperature formula optimization.
2)Has the battery’s low-temperature performance been validated?
A qualified heated insole battery supplier should guarantee that their batteries maintain over 80% capacity during a 1C discharge at –20°C. They should also be able to provide relevant certifications such as UN38.3, IEC62133, CE, RoHS, and MSDS to meet the compliance requirements of various countries and sales channels.
3)Does the packaging method support IP-rated waterproofing?
Since insoles are used in damp environments and can easily accumulate sweat, batteries must be protected using waterproof packaging materials (such as PU soft packs, heat-sealed tubing, or potting encapsulation). Reputable suppliers typically conduct drip tests and apply IPX4-grade waterproof protection processes during the PACK stage.
4)Do they support small batch prototyping and fast delivery?
Early-stage product development often requires multiple rounds of prototyping and testing. Suppliers should offer flexible MOQs (e.g., 200–500 units), quick sample delivery times (10–15 days), and work closely with device manufacturers to ensure tooling compatibility and proper mechanical integration of the battery modules.
5)Do they offer one-on-one technical support?
The structure, wiring, cell positioning, and battery bonding process for heated insole batteries often need to be optimized in coordination with the overall device design. Therefore, the supplier should provide experienced project engineers to offer full-process support, including thermal analysis, current matching recommendations, and installation guidance.
6)Industry reputation and application cases
It is advisable to choose a manufacturer with proven experience in wearable heating products such as heated clothing or insoles. Understanding their client base, after-sales response capabilities, and return policies is also important. The more relevant their past projects are, the lower the risk for your own product development.
In summary, an ideal battery supplier is not just a vendor—but a solution partner who understands your product and the challenges of your industry.
6、Which Manufacturers Specialize in the Development and Production of Heated Insole Batteries?
As a professional lithium-ion battery manufacturer, Iray Energy has been deeply involved in the field of wearable and smart heating batteries for over a decade. The company operates a modern production facility covering more than 10,000㎡, equipped with fully automated PACK lines, a rigorous quality control system, and a team of 32 experienced engineers. Iray Energy’s core advantages include:

  • Strong Customization Capabilities:
    Able to customize soft-pack battery cells in various sizes according to insole thickness, structural design, and temperature requirements.

  • Mature Low-Temperature Battery Solutions:
    Supports normal discharge at –40°C, ensuring stable performance of products in harsh winter environments.

  • Diverse Packaging Options:
    Offers TPU encapsulation, potting, and custom wiring structures to meet various structural needs.

  • Complete Certification System:
    Provides certifications such as UN38.3, MSDS, IEC62133, CE, and RoHS to ensure global compliance.

  • Fast Response and Flexible Delivery:
    Quick sample turnaround and low minimum order quantities make it ideal for early-stage prototyping and market testing.

  • One-on-One Technical Support:
    Dedicated project engineers are involved throughout the entire process—from design to production—enhancing development efficiency.

Iray Energy has successfully provided reliable battery solutions to numerous smart heated insole brands and outdoor sports companies, with products widely exported to extremely cold markets including Europe, the United States, Japan, Canada, and Russia.
7、What Are the Usage Precautions for Heated Insole Batteries?

Even when using high-quality lithium battery modules, improper handling by users can lead to safety risks or significantly shorten the battery’s lifespan. Therefore, whether you are a manufacturer, distributor, or end user, it is essential to fully understand and follow the usage precautions outlined below:

7.1 Recommendations for Consumers:

  • Avoid prolonged use of the highest heat setting:
    While the high-heat mode provides rapid warming, it also places a significant load on the battery cell. It is recommended to limit use of the highest setting to no more than 30 minutes, then switch to medium or low settings to maintain warmth—this conserves energy and prolongs battery life.

  • Always use the original charger:
    Heated insole batteries typically require 5V or 8.4V dedicated lithium battery chargers. Using a 12V charger or high-current fast-charging device can cause overvoltage, overheating, or even battery swelling.

  • Do not heat while charging:
    Most lithium battery protection boards do not support simultaneous charging and discharging. Forcing both operations may cause the BMS (Battery Management System) to misjudge the state, triggering protection or thermal runaway.

  • Do not dry with high heat or expose to direct sunlight:
    If the insoles become damp, allow them to air-dry naturally. Never place them in a dryer or on a heater, as this may cause explosion risks or damage the battery.

  • Maintain a 50% charge during long-term storage:
    If the product is not used for an extended period (e.g., after winter), charge the battery to about 50%, disconnect it, and recharge/discharge once every 3 months to prevent deep discharge and battery failure.

7.2 Design Recommendations for OEM/ODM Manufacturers:

  • Reserve sufficient space for battery placement and routing to avoid excessive bending.

  • Ensure the current drawn by the heating element does not exceed the battery’s discharge capacity; <2C is recommended.

  • Integrate NTC thermal sensors and multiple protection circuits into the PCB (such as OVP, UVP, SCP, OTP).

  • Apply additional sealing layers or nano-coatings to protect against humid environments.

  • Incorporate battery status indicators or power level displays to prevent user misuse.

FAQs About Heated Insoles Battery

Can the battery in heated insoles be replaced?
Most heated insoles use built-in lithium batteries that are not user-replaceable. If replacement is necessary, it is recommended to contact the brand manufacturer or an authorized service center.
The usage time depends on the battery capacity and the heating level. Typically, a 2000mAh battery can last for 3–5 hours on medium setting and up to 8 hours on low setting.
This is not recommended. Doing so may cause the protection circuit to fail or lead to battery overheating.
Always use the original charger provided by the manufacturer. Most heated insole batteries require a 5V or 8.4V dedicated charger. Using an incompatible charger may cause overvoltage or damage.
Most heated insole batteries have some level of water resistance or moisture protection (such as IPX4), but they should not be fully submerged in water or directly washed.
Before storage, it is recommended to charge the battery to about 50%, keep it in a cool, dry place, and perform a full charge and discharge every 2–3 months to prevent over-discharge damage.
The battery itself does not interfere with medical devices, but insoles with Bluetooth or other wireless control functions may generate slight electromagnetic interference. If in doubt, please consult your doctor before use.
Not recommended. Using non-original batteries may result in incompatible voltage, incorrect dimensions, or lack of protection circuits, which can lead to overheating or device malfunction.

📌 Tip:
For professional Heated Insoles Battery customization or replacement solutions, feel free to contact the IrayEnergy engineering team. We’re here to provide efficient, reliable, and high-performance power solutions!

More questions? Email us