Continuing from the previous issue, I introduce the Lithium D530 wristwatch from SANYO Electric Co..
For some reason, I am attracted to SANYO watches and have always bought them whenever I find them.
Among them, this model is my favorite along with the amorton S517 that I introduced earlier.

What is the symbol in the upper right corner? I looked at the back cover and find an illustration of a windsurfer.
It is labeled “WATER RESIST 50m,” so it appears that water resistance was a selling point.
It is water resistant to 50m, but the back cover is a simple insert type.
In Japan, at that time, it was popular to put illustrations related to the sea on waterproof watches for marine sports.
Casio's “Marlin model" is very famous.

What makes this model my favorite is that it is full of 80's taste everywhere.
The “alarm symbol” and “running man” are reminiscent of Nintendo's GameWatch (launched in 1980), which was popular at the same time.

This model actually has another significant feature.
The "Lithium" in the model name stands for lithium battery.
Compared to other button batteries (alkaline button battery: LR, silver oxide battery: SR), the lithium battery (CR) has a higher voltage (3V) and thus has advantages such as brighter light and louder alarm sound.
SANYO Electric, in particular, took advantage of its ability to develop and manufacture batteries in-house and created a battery specifically for SANYO wristwatches.
This is the "CR736-2" battery.
There was also a smaller "CR636-2" battery for ladies' models.

Now that Sanyo Electric was acquired by Panasonic, it is impossible to buy this particular special battery.
So why is this model still working today?
Actually, using the feature that the minus pole is only in the center, two SR716SW button batteries (1.55V) are stacked (in series) in the middle, and used as a voltage of about 3V.
The long, narrow sides have insulator spacers to prevent the batteries from shifting outside.
(This is a method I found on the Internet and has worked fine so far, but please do so at your own risk.)

As a result, it is no longer "lithium battery model", but it is still usable, so let's call it good.