After the reports of it not working I checked it out today when I was crusing for caches on the Nashua River. When I pulled it out it chirped right away. I measured the battery voltage at almost 4 volts.
I atached the laminated travel bug card that I forgot when I released it and put it back in.
One note, the chirps and clicks are not very loud at all. The blink should be obvious but happen only every 13 seconds when "dark".