What Battery Is Equivalent to LR66?

What Is LR66 Battery

The LR66 battery is a common alkaline button cell battery used in small electronic devices such as toys and calculators. It functions similarly to other 1.5V button cells and can be a more economical alternative to silver oxide batteries for devices that don't require long-term reliability.

LR66 Specification

Type: Alkaline button cell.

Voltage: 1.5V.

Dimensions: Approximately 6.8mm in diameter and 2.6mm in height.

Capacity: Typically 16mAh or 18mAh.

Weight: Approximately 0.32g-0.36g.

Features

Chemical Type: Alkaline, a non-rechargeable battery.

LR66 batteries have a low self-discharge rate of less than 1% per year, which gives them a shelf life of over 10 years.

LR66 batteries are disposable and non-rechargeable.

Applications

LR66 batteries are commonly used in small electronic devices such as watches, cameras, calculators, toys, laser pointers, digital thermometers, and electronic scales.

What Battery Is Equivalent to LR66

You can replace LR66 batteries with equivalent button batteries, such as AG4, LR626, 377, or SR626SW. Because these batteries share the same size and voltage (1.5V), they are generally interchangeable. However, there are some caveats:

LR66 batteries are alkaline, meaning they use an alkaline electrolyte. SR626SW batteries are silver oxide batteries. Silver oxide batteries, known for their stable voltage and long life, are often used in precision devices requiring high voltage stability. LR66 alkaline batteries, on the other hand, are widely used in small, everyday electronic devices where voltage stability is less critical. Please check the specific requirements of your device. Some devices are designed to use the stable voltage of silver oxide batteries, while others can use alkaline batteries. Here are some examples:

Device suitable for the SR626SW silver oxide battery:

Watches: Both analog and digital watches require a stable voltage to maintain accurate timekeeping. The SR626SW battery meets this requirement, as seen in some models from brands like Casio, Longines, and Tissot. Calculators: Some basic handheld calculators and scientific calculators require a stable power supply to ensure accurate calculations and proper function.

Medical Devices: Medical devices like blood glucose monitors and hearing aids require extremely stable and reliable batteries. SR626SW batteries provide these devices with stable voltage, ensuring precise operation.

Car Remote Controls: Car remote controls require stable voltage to ensure accurate signal transmission. SR626SW batteries provide reliable power.

Device Suitable for LR66 Alkaline Batteries:

Toys: Small electronic toys, such as remote-controlled cars and animatronics, require less stable voltage. LR66 batteries provide sufficient power at a relatively low cost.

LED Lights: Some small LED lights, such as keychain lights and miniature flashlights, typically use LR66 batteries to meet their lighting needs.

Cameras: The light meters of some older film cameras, or the auxiliary functions of some small digital cameras, may use LR66 batteries. Laser pointer: Small laser pointers usually have low power, and LR66 batteries can provide them with basic power support so that they can emit lasers normally.

LR66 Alternatives Comparison Table

Safe Disposal

To safely dispose of LR66 button batteries, wrap their terminals with non-conductive tape. This will prevent them from shorting and potentially causing sparks or fire. Place the batteries in a plastic bag and take them to a battery recycling point at a participating electronics store or local household hazardous waste (HHW) disposal facility. In Hong Kong, for example, many large supermarkets, electronics stores, or home centers that sell batteries have drop-off points for portable disposable batteries. You can also obtain information about battery disposal from the Environmental Protection Department (EPD).

Do not dispose of in regular trash:

Do not dispose of LR66 or other button batteries in regular household trash or municipal recycling bins. They contain chemicals that may be harmful to the environment and can also pose a fire hazard in garbage trucks or incinerators.

Safety Precautions

For safe use of LR66 batteries, do not attempt to charge them. Attempting to charge may result in leakage, explosion, or other damage.

Insert the battery according to the correct polarity (usually with the "+" positive side facing up).

Store the battery out of the reach of children and pets to prevent accidental ingestion. Avoid physical damage such as heat, fire, short circuiting, or disassembly.

Do not disassemble: Do not attempt to disassemble, puncture, or crush the battery.

Store the battery in a cool, dry place, away from direct sunlight.

Button Battery Purchasing and Replacement Tips

First, check the device manual:

The model number listed in the manual is the most accurate.

Pay attention to size and voltage:

Make sure the new battery's diameter, height, and voltage (1.5V) match the old one.

Choosing a chemistry:

For general uses (such as toys and calculators), LR41 (alkaline) offers the best value.

For devices requiring stable voltage and long life (such as watches and precision instruments), SR41 (silver oxide) is recommended.

FAQ

1. Can I replace an LR66 with an SR66 or 377 battery?

Yes, in many cases you can. The SR66 (also called 377) is the silver oxide version of the LR66. While both have the same size and voltage, SR66 batteries usually last longer and provide more stable output, making them a better choice for precision devices like watches.

2. What is the difference between LR66 and SR66?

LR66 → Alkaline chemistry, lower cost, shorter lifespan.

SR66/377 → Silver oxide chemistry, higher cost, but longer-lasting and more reliable performance.

3. How long does an LR66 battery last? Battery life depends on the device, but LR66 alkaline cells typically last a few months to a year. Silver oxide equivalents (SR66/377) often last longer.

4. Are LR66 batteries rechargeable? No, LR66 batteries are not rechargeable. Attempting to recharge them may cause leakage or damage.

5. Can I use LR44 instead of LR66? No, LR44 and LR66 are not the same. The LR44 is larger in size (11.6 mm diameter vs. 6.8 mm diameter for LR66), so it will not fit in devices designed for LR66.

6. Where can I buy LR66 or its equivalents? You can find LR66 batteries and equivalents online (Amazon, eBay, battery specialty stores) or at local electronics and watch repair shops. (When you see "LR66," it's most likely referring to the standard LR41 battery. When shopping in stores or online, you should search for LR41.)

7. How should I dispose of used LR66 batteries? Used LR66 batteries should be recycled properly at a battery recycling center. Do not throw them in regular trash as they contain materials harmful to the environment.

8. Which brand of LR66 equivalents is most reliable? Trusted brands include Duracell, Energizer, Maxell, Renata, and Sony, especially for SR66/377 silver oxide versions that offer better performance.