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Pulse Oximeter Battery Application

In the modern fields of medical care and health monitoring, pulse oximeters have become essential devices widely used in hospitals, emergency services, and home settings. The accuracy and stability of a pulse oximeter often directly impact the user’s health and even life safety. One of the key components ensuring its proper operation is the internal battery system.
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Pulse Oximeter Battery Guide | How to Choose Battery for Pulse Oximeter?

Compared to traditional medical equipment, pulse oximeters are compact, highly portable, and low in power consumption. However, they place significantly higher demands on battery performance: requiring not only long-lasting and stable power supply but also a high level of safety and durability. In certain scenarios—such as high altitudes, low temperatures, or outdoor emergency situations—there are even greater challenges for battery endurance and environmental adaptability. With the addition of smart features like Bluetooth connectivity, OLED displays, and data storage, the pressure on the battery system increases further.
Nevertheless, the market offers a wide range of battery solutions, each differing significantly in terms of runtime, safety, size, and cost. For OEM/ODM manufacturers, branded medical device companies, and even end-users, selecting a pulse oximeter battery that is both reliable and cost-effective is critically important.

1、What Is a Pulse Oximeter Battery?

As the name suggests, a pulse oximeter battery is the power source used to operate a pulse oximeter. As an electronic medical device, a pulse oximeter typically consists of a main control chip, infrared and red light LED emitters, a photodetector, a display module, and data communication components. The proper functioning of all these components relies on a stable and continuous power supply. Therefore, the battery is not merely a source of energy, but a vital core component that determines the device’s performance, battery life, safety, and overall user experience.

2、How Does a Pulse Oximeter Work?
A pulse oximeter is a non-invasive optical sensing device primarily used to measure the oxygen saturation level (SpO₂) and pulse rate (heart rate) in human blood. Its working principle combines photoplethysmography (PPG) with the Beer–Lambert law of light absorption ratios. By using a non-invasive method, it continuously monitors the absorption of different wavelengths of light by blood to calculate the oxygen content. The device is typically clipped onto a fingertip, earlobe, or toe, and uses optical sensing technology to track real-time changes in blood oxygen saturation and pulse frequency.
3、What Are the Basic Requirements for Pulse Oximeter Batteries?
As a type of medical electronic device, pulse oximeters place much higher demands on battery performance than ordinary consumer electronics. These demands include strict standards for power stability, safety, response speed, and service life. Such requirements are driven not only by the device’s core functionalities but also by the actual usage scenarios. Typically, a pulse oximeter battery must meet the following basic requirements:
1) Stable Voltage Output to Ensure Accurate Data
The core functionality of a pulse oximeter relies on precise optical detection and digital signal processing. This means that even during long-term operation or under low battery conditions, the battery must provide a stable voltage output. For example, MCUs and photodetectors often operate at 3.3V or 5V. If the voltage fluctuates, the LED light source may become unstable or signal processing may be disrupted, leading to inaccurate SpO₂ readings. Therefore, the battery must feature an excellent discharge platform and voltage stability.
2) Compact Design and High Energy Density
Pulse oximeters are typically designed to be wearable or portable, and thus have very limited internal space. The battery must be small in size yet capable of supplying sufficient power for extended operation. As a result, high energy density becomes a critical metric.
3) Long Battery Life and Low Self-Discharge Rate
In scenarios such as home health monitoring, high-altitude expeditions, or outdoor sports, users often expect the device to operate for several days on a single charge. Therefore, in addition to adequate capacity, the battery must also have a low self-discharge rate to ensure that energy is not significantly lost when the device is not in use.
4) Fast Charging with Long Cycle Life
For rechargeable pulse oximeters, users often expect fast charging—especially in emergency medical or athletic scenarios. The battery must support high charging efficiency, often requiring a charge rate of 3C or higher. At the same time, the battery should retain at least 80% of its capacity after 300–800 full charge-discharge cycles to meet longevity expectations.
5) High Safety and Wide Temperature Tolerance
As a medical device, safety is a non-negotiable requirement. The battery must pass protection against overcharge, over-discharge, short circuit, compression, impact, overcurrent, and temperature extremes. It should maintain safe operation under a variety of environmental conditions—especially high temperatures (above 50°C), low temperatures (below –20°C), and high-altitude environments.
4、Common Types of Pulse Oximeter Batteries and Comparison

Depending on the product positioning and usage needs, pulse oximeters on the market generally use three main types of batteries: disposable alkaline batteries (such as AAA), lithium primary batteries (such as CR2032 coin cells), and rechargeable lithium-ion or lithium-polymer batteries. Each type has its own advantages and disadvantages in terms of capacity, size, rechargeability, safety, application scenarios, and cost control.

4.1 Alkaline Batteries (e.g., AAA, AA)

Alkaline batteries are the most common type of disposable battery used in traditional pulse oximeters, especially in entry-level or non-smart models.

  • Advantages:Low cost; easily available for replacement at home or in supermarkets.

  • Disadvantages:Low energy density, large size, limited battery life, and poor environmental friendliness.

4.2 Lithium Primary Batteries (e.g., CR2032 Coin Cells)

CR2032 and similar coin cell batteries are commonly used in compact pulse oximeters, particularly those with minimalist designs, no displays, or low power consumption.

  • Advantages:Compact size, suitable for ultra-thin devices; very low self-discharge rate.

  • Disadvantages:Low capacity; not rechargeable.

4.3 Rechargeable Lithium-Ion Batteries

Lithium-ion batteries (Li-ion) are the mainstream power solution for today’s mid-to-high-end pulse oximeters, especially smart Bluetooth-enabled and wearable models.

  • Advantages:Customizable sizes; high energy density; environmentally friendly and energy-efficient; long cycle life.

  • Disadvantages:Relatively higher cost; each product usually requires a customized battery design.

5、Which Manufacturers Specialize in Developing Pulse Oximeter Batteries?

Among the many battery manufacturers in the market, IrayEnergy stands out as a professional lithium battery developer and provider of customized power solutions. The company has a complete R&D chain dedicated to medical-grade batteries and has accumulated deep technical expertise in power systems for pulse oximeters, infrared thermometers, blood pressure monitors, and other medical devices.
At present, IrayEnergy possesses in-house capabilities for die-cutting and packaging processes and supports the customization of soft-pack lithium batteries starting from just 1mm in thickness. Battery voltage, capacity, dimensions, and protection circuit parameters can all be tailored precisely to customer requirements. The company also supports custom designs for ultra-thin, embedded, and irregularly shaped batteries, fully addressing the structural challenges of “lightweight and high-reliability” demands in various medical devices.
IrayEnergy’s lithium-ion batteries are widely exported to North America, Europe, Japan, and South Korea, and the company is well-versed in international certification and regulatory compliance requirements for medical products in global markets.

6、What Are the Key Precautions When Using Pulse Oximeter Batteries?

Whether using a smart pulse oximeter powered by a rechargeable lithium-ion battery or a portable model that runs on alkaline or coin-cell batteries, users should pay close attention to battery maintenance in daily use. Below are several important precautions from the perspective of a battery manufacturer regarding the safe and effective use of pulse oximeter batteries:

1) Always Use the Original Manufacturer's Battery
Whether replacing a disposable battery or using a rechargeable one, it is strongly recommended to use only batteries from the original equipment manufacturer (OEM) or those that meet certified specifications. Non-matching batteries may result in voltage, current, or connector mismatches, potentially causing circuit damage, data errors, or even battery swelling, overheating, and safety hazards.
2) Do Not Use Incompatible Chargers
Lithium-ion batteries have strict requirements for charging voltage and current. Do not use mobile phone chargers, fast-charging adapters, or power banks that are not specifically designed for the device. In particular, avoid fast chargers with output voltage exceeding 5V. Overvoltage or overcurrent charging may lead to battery swelling, overheating, or even fire—posing serious safety risks.
3) Avoid Deep Discharge or Prolonged Overcharging
If the device is not used for an extended period, do not let the battery drain completely or remain at 100% charge for a long time. It is advisable to maintain the battery at a charge level of 40%–60% and perform a full charge-discharge cycle every 3 months. Over-discharge can cause the battery voltage to fall below the protection threshold, making it unresponsive; overcharging accelerates cell degradation and may damage the protection circuit.
4) Avoid Using the Device While Charging

Although some smart pulse oximeters support operation while charging, it is not recommended to use the device during charging due to safety and battery longevity concerns. Charging increases internal temperature, and if combined with processor and Bluetooth module activity, it may cause localized overheating.

5) Replace Aging or Faulty Batteries Promptly

If the pulse oximeter shows signs such as noticeably reduced runtime, faster charging than usual, frequent reboots, unresponsive touchscreen, or battery compartment overheating, the battery may be aging or damaged. Lithium-ion batteries typically have a cycle life of 300–800 full charges. Continued use beyond this lifespan increases safety risks. If you notice signs of swelling, leakage, or unusual odors, stop using the battery immediately.

FAQs About Pulse Oximeter Battery

How long does a pulse oximeter last on a full charge?

Battery life depends on the battery capacity and how frequently the device is used. A common 500mAh lithium battery can typically support 10 to 15 days of use for routine home monitoring. If Bluetooth, data synchronization, or continuous monitoring features are enabled, the usage time will be reduced accordingly.

For pulse oximeters with standard USB charging, the battery usually takes 1 to 2 hours to fully charge. Devices that support fast charging may charge faster. The actual time depends on the charger’s output current and the battery’s capacity.
Yes. Unstable voltage or low battery level may cause the LED light source to flicker or dim, leading to incorrect signal processing and inaccurate SpO₂ or pulse rate readings.
This could be a battery-related issue. If the battery voltage drops suddenly, the voltage platform is unstable, there’s poor internal contact, or the BMS triggers a protection mechanism, the device may shut down or reboot. It is recommended to check the battery connection, charging status, or try replacing the battery.
It is not recommended. Many phone fast chargers deliver a voltage that exceeds the device’s requirements and may damage the battery or protection circuitry. It is best to use the original or manufacturer-approved charger to ensure safety.

📌 Tip:
For professional Pulse Oximeter 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!

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