Sharp electronic organizers with the IC card slot (Wizard OZ/IQ/PA/PI series)

[Dave Britten]

(02-15-2022 02:24 AM)Xorand Wrote:  Interesting thing today. I had bought an OZ-701A Time Expense Manager IC Card off eBay. It was listed as new in open box. Though the box had some outer wear, the card looked clean. It also still had the original button cell battery still sealed in plastic.

I pulled everything out and opened up the plastic envelope and pulled out the battery. It was a Maxell branded CR2016 battery. It had what I presume was a date stamp on it of 89-04 (1989 would be about right). I took it out to the garage assuming it would be dead (it had not leaked) and to see if I have any 2016s in my battery stash.

Out of curiosity, I pulled out the multimeter and checked the battery. It had 3.27 volts (rated for "3V") charge on it. Huh. I put it in the card and put the card in the OZ-7000 and it worked fine, though the organizer might need a new backup battery as it had lost date/time and gave me a memory loss error. Unless that's normal when putting in a new card? What little information I had typed into the organizer was still there.

Coin batteries tend to have crazy shelf life, and often work fine even decades past the "use by" date, so while that's very impressive, it's not entirely surprising. Even many old NES cartridges from the '80s that use a CR2032 for storing save data (Zelda, etc.) still save just fine, thanks to extremely low-power SRAMs. On the other hand, I've occasionally found coin batteries that appear to read acceptable unloaded voltage, but have aged to the point that they can't deliver useful current.

Normally when you pop a new card into the organizer, you'll see that message about the card data needing to be initialized, so that might have been what you saw. Not sure why the organizer would have lost its date/time without losing any other stored data, though.