There is a practical use. Flash an LED every blue moon in my coffin. The entire circuit with the could be encapsulated in resin so it lasts until the Great Tribulation. At least I'll get some entertainment whilst waiting... waiting... waiting....
Notice the spelling on their AA cell (Dave seemed to have missed it). It says "Diamnond Battery." Along with the PTH pins on SMD parts, its a big red flag. I wonder if some of them work at the "Microsoft Help Desk" as their daytime job.