The Down Range Forum
Member Section => Down Range Cafe => Topic started by: Big Frank on August 28, 2025, 11:50:21 PM
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Here's a picture of the Lithium Vanadium Pentoxide (LiV2O5) battery I got for the memory in my old Garmin GPS 12. And the 616 cubic inch cardboard box it came in. The battery is 12.5 mm in diameter, almost as big as a .50 caliber bullet (12.7mm), and 2mm thick, less than half the size of a BB (4.5mm). That makes it 1/100 of a cubic inch, meaning the box was more than 60,000 times bigger than the battery. At least my little bitty battery didn't get lost. I never heard of Lithium Vanadium Pentoxide batteries before, and the first place I saw these for sale was Amazon where they were $28.69 + tax for a Technical Precision Replacement for PANASONIC VL1220-1VC Battery. I found a genuine Panasonic battery at DigiKey for $3.18 + $6.99 shipping, and no taxes. So I bought the $3 battery, not the $30 battery, obviously. It was a pain in the butt to de-solder the tabs of the old battery and pull it out and re-solder the new one back in without screwing anything up.
But when I glued the 2 halves of the GPS back together with Amazing Goop it shorted out about 16 lines of the LCD display, both vertical and horizontal lines. They were just blank. I took it apart, scraped all the Goop off and let it set for a couple of days. I put it back together and held it together with my hands as I put the 4 AA batteries in and turned it on. It worked like new. Then I Gooped it up and it was all messed up again. After the 3rd time, I gutted it and glued a 40mm diameter compass in with a whole lot of Goop. I forgot to take pics before I gift wrapped it. I'm giving it to my friend as a gag gift for his retirement, before I give him his real gift. So he can always find his way back to his friends and loved ones. Doggies too. Friday is his last day of work and I'm going up north this weekend. I'll try to remember to take some pics of the "poor man's GPS" while I'm there. There were no screws or any other hardware holding the front and rear plastic shells of the unit together, just a slight trace of silicone or something that mostly melted and ran out a few years ago. And probably a few drops of super glue because it popped pretty loud when I pried it apart with a wide-bladed screwdriver.
https://www.amazon.com/Replacement-PANASONIC-VL1220-1VC-Technical-Precision/dp/B07QX1ZVY4/ref=sr_1_19
https://www.digikey.com/en/products/detail/panasonic-energy/VL-1220-FCN/2404070
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Because of the GPS week number rollover, my unit said it was December 2003 or 2004. Something like that. But tech support said if I set it to the right time zone everything else would work right. I think it was showing the time as 2:00 when it was 4:00. I don't know how many waypoints I had saved, not the maximum of 500, but they're all gone. My friends and I are going to have to try to track down a deer camp we found in the woods on public land. We camped there overnight on a 2-day ATV trip.
The GPS week number rollover is a phenomenon that happens every 1,024 weeks, or about 19.6 years. The Global Positioning System (GPS) broadcasts a date which includes a week number counter stored in only ten binary digits, whose range is therefore 0–1,023. After 1,023, an integer overflow causes the internal value to roll over, changing to zero again. Software that is not coded to anticipate the rollover to zero may stop working or could be moved back in time by a multiple of approximately 20 years. GPS is not only used for positioning, but also for accurate time. Time is used to accurately synchronize payment operations, broadcasters, and mobile operators.
1999 occurrence
The first rollover took place midnight (UTC) August 21 to 22, 1999.
NavCen issued an advisory prior to the rollover stating that some devices would not tolerate the rollover. Because of the relatively limited use of GPS during the 1999 rollover, disruption was minor.
2019 occurrence
The second rollover occurred on the night of April 6 to 7, 2019, when GPS Week 2,047, represented as 1,023 in the counter, advanced and rolled over to 0 within the counter. The United States Department of Homeland Security, the International Civil Aviation Organization, and others issued a warning about this event.
Products known to have been affected by the 2019 rollover include Honeywell's flight management and navigation software that caused delays for a KLM flight and cancellations for numerous flights in China because the technicians failed to patch the software. Furthermore, the New York City Wireless Network (NYCWiN), a private network for New York City's municipal services, crashed. Other products that were affected by the rollover include cellphones that were sold in 2013 or earlier, certain types of older Vaisala radiosonde groundstations, suspending launches at some stations for up to two weeks, NOAA's weather buoys, many scientific instruments, and consumer GPS navigation devices.
Prior to return to normal standard time from daylight saving time during the morning of November 3, 2019, Apple issued a warning to owners of iPhone and iPad devices sold before 2012 to update or risk losing Internet connectivity.
Some Furuno GPS models had an internal rollover on January 2, 2022. If the equipment was not updated with the latest software version, the equipment's date would no longer be displayed correctly.
Honda and Acura cars manufactured between 2004 and 2012 containing GPS navigation systems incorrectly displayed the year 2022 as 2002, with a time offset by several minutes. This problem was due to an overflow on the GPS epoch.
All Porsche models with PCM2.1 are also affected according to bulletin #1904 released by Porsche on December 20, 2019.
Users of the GoPro Karma camera drone reported that their drones were grounded in early January 2020 due to a GPS-related glitch. GoPro subsequently revealed that the glitch was caused by the GPS week number rollover phenomenon and that they were working on a firmware update to fix the issue.
It's like the "Y2K Bug", but real. And it occurs more often than every 20 years, not once in 1,000 years. It sound to me like a case of PPPP, Piss Poor Prior Planning. You could call that a P4 problem for short.