Back in the 1980's, in high school, I think it was, I purchased a Canon LC-27 pocket calculator for a couple bucks. That was around thirty five years ago and I still have the calculator now. In fact, it sits on my desk at work, beside my keyboard and I use it nearly every day in my job as a producer. Now here's the weird part; in the thirty five or so years since I have owned this calculator, I have never once opened it or changed the original battery that powers it. For the last fifteen years I have been mildly freaked out thinking about how a small, 1.5 volt calculator battery (there is a diagram of it on the back of the device, that's how I know) can last so long. These days I see some modern alkaline batteries advertising the ability to hold a charage (if it isn't used) for up to 10 years. Impressive as that sounds, 35 years is just insane, particularly since this calculator has been in constant use.
I have tried to look it up on the internet but the closest I can find is a Canon LC-27H, so I don't know the exact year it was made. I wish I did. I don't dare open the case lest I discover a magical gremlin or alien technology inside. I suspect this device may have fallen off a UFO or maybe once belonged to a scientist in Area 51. Either that or it is somehow tapping my body's electrical field to recharge itself. Vampire battery. Actually, I have no rational explanation for a battery lasting that long but my Canon LC-27 definitely qualifies as one of my favorite things.