Solar Analog-Digital Alarm Chronograph
Cal. Miyota C030-086853K

The watch stopped at 08:52...
Why I know about that later...When took that watch out of the vault in Switzerland 2 years ago, the watch had stopped at 08:52 and the analog part would not budge. The digital display showed some very weak signal, when tilting the display one could see that the circuit was still alive.
In November 2003 I decided to check the battery and took those movement pictures along with many others. I had decided to invest a couple of days to remove all dead batteries in all the quartz watches in the house. I made a note that I should buy a backup battery 280-403 in my battery spreadsheet and thought I would order one later, placed the watch back on the shelf facing the window and basically forgot about it.
In April I started noticing an alarm sound going off at around 7:30 AM, but normally I was too late to quickly follow the sound to find that beeping watch. There are maybe 20 living quartz watches in my study, so it took me a while to check them all. None of them was set. I decided just to forget about it again.
Thus Sunday morning 23rd May 2004 I was quick enough and found that the sound came from this "Butterfly" (my name) Ana-digi Alarm Chrono. I was so surprised. Obviously the watch did not need a new backup battery (the buffer for the stored energy from the solar cells) and had slowly tanked enough daylight to start beeping faithfully every morning at 7:30 AM.

Great News in my eyes, because that means that Eco Drive buffer batteries will definitely last for 30 years. If that battery lasted almost 20 years laying 8 of them in the dark, then I trust modern Eco Drive batteries produced today will most likely survive 3 decades. I was very happy today and you can see how happy I was, I shot a lot of pictures of my "new" and running watch!