I haven’t used the device for a while, so when I took out the battery and stored it in the drawer of the desk, the battery was swollen. What can be considered?

Button-type batteries have a structure in which the distance between the positive and negative poles of the battery seal is extremely narrow. Therefore, when the button-type battery is stored together with a metal necklace, hairpin, etc., or when multiple button-type batteries are stored in a stacked state, the metal comes into contact with the positive and negative poles of the button-type battery. Due to a short circuit, gas may be generated inside the battery and the battery may swell. Do not use swelling batteries, and insulate the (+) and (-) poles of each battery with insulating tape, and use the “button battery collection can” installed in your local electronics store, watch store, camera store, etc. Please put it in.
When storing button-type batteries removed from the device, it is recommended to store them individually in a small plastic bag to prevent short circuits.

The battery is dead, so I replaced it with a new one, but the device does not work. What can you think of?

Button-type batteries have a structure in which the distance between the positive and negative poles of the battery seal is extremely narrow. Therefore, when the battery is loaded in the device, the metal parts such as the terminals of the device may come into contact with the positive and negative poles of the battery, resulting in a short circuit.
If the battery is short-circuited, the voltage will drop temporarily. If the short-circuit time is short, remove the battery and leave it for about 3 hours to recover the voltage, so you can use it by re-loading the battery so as not to short-circuit it. If you still cannot use it, please contact our customer service center.

When I checked a new coin cell battery with a battery tester, the voltage was lower than the nominal voltage. Is this normal?

It depends on the battery tester you are using, but in the case of an analog tester, it is not possible to measure correctly because it does not match the characteristics of the battery because it measures while passing a large current. Even among the devices sold that can measure button batteries, it may not be possible to measure correctly with devices that measure using the same principle.
Generally, use a measuring instrument called a digital multimeter (tester) or digital voltmeter, and measure with an input resistance of 1 megaohm or more.

What is the recommended expiration date?

JIS (Japanese Industrial Standards) defines the [Recommended usage period] as “a period in which the battery operates normally if it is started to be used within that period and satisfies the performance such as the duration specified in JIS”. The recommended expiration date is 2 digits per month-year (09-2014 for September 2014), and is displayed on the package for small batteries such as button batteries.
The [Recommended usage period] is not set in JIS and is to be agreed by each battery manufacturer.

Is SR44 compatible with LR44?

SR button batteries are compatible with the same 1.5V type batteries as LR button batteries. The LR button battery is a battery that has been commercialized as a low-priced version of the SR button battery.

Is there a compatibility table with batteries made overseas?

Please refer to the URL below.

-> Model numbers and correspondence tables for button-type and coin-type batteries from each company

When I opened it to replace the battery in my watch, I found a battery called SR626W. When I went to the store, only SR626SW was sold, so I will put it in instead. Is there not a problem?

Basically, replace the battery with the same product name.
The “W” in the battery product names SR ○○○ W and SR ○○○ SW indicates that the watch battery standard is satisfied.
Those without the “W” notation, such as SR44, are for general use and do not guarantee that they will meet the standards for wristwatch batteries.
The battery with the product name SR ○○○ W is a high-rate type (for heavy loads) suitable for multifunctional (digital) watches equipped with a backlight, stopwatch, alarm function, etc.
The battery with the product name SR ○○○ SW is a low-rate type (for light loads) suitable for analog clocks that move only the hands of the clock.
Inserting SW type batteries into a digital clock may cause problems such as those functions not working properly or the clock stopping. Use W-type batteries for digital and multifunctional watches, and SW-type batteries for analog watches.
For details, check the instruction manual of the device and select the specified battery.

When I opened it to replace the battery in my watch, I found a battery called SR626W. When I went to the store, only SR626SW was sold, so I will put it in instead. Is there not a problem?

Basically, replace the battery with the same product name.
The “W” in the battery product names SR ○○○ W and SR ○○○ SW indicates that the watch battery standard is satisfied.
Those without the “W” notation, such as SR44, are for general use and do not guarantee that they will meet the standards for wristwatch batteries.
The battery with the product name SR ○○○ W is a high-rate type (for heavy loads) suitable for multifunctional (digital) watches equipped with a backlight, stopwatch, alarm function, etc.
The battery with the product name SR ○○○ SW is a low-rate type (for light loads) suitable for analog clocks that move only the hands of the clock.
Inserting SW type batteries into a digital clock may cause problems such as those functions not working properly or the clock stopping. Use W-type batteries for digital and multifunctional watches, and SW-type batteries for analog watches.
For details, check the instruction manual of the device and select the specified battery.