Comment by IsopropylMalbec

1 day ago

The battery on that circuit looks very much like a backup battery we have connected to our house alarm.

We moved in to the house in 2003 and that battery died this year, so I would imagine that it is already or will very soon die. That said, if it's a backup battery and the electricity supply is stable then it may not make any difference.

11 comments

IsopropylMalbec

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js2  1 day ago

It's a standard sealed lead acid battery:

https://www.rapidonline.com/yuasa-yuvolt-yucel-y1-2-6-valve-...

https://static.rapidonline.com/pdf/18-5207_v2.pdf

Design spec is up to 5 years. The one in the photo looks like it may have a date written in Sharpie on the side. I don't think it's 25 years old though. The "090323" on top could be DDMMYY indicating a battery from 2023.

  • compiler-guy  21 hours ago

    I agree with the 2023 decode there, but there is still a bit of a puzzle:

    If someone knew to replace the battery just three years ago, I would expect they also would have enough knowledge to set the clock itself. Or at least explain what was going on. Maybe this person isn't connected with the building anymore. But I would expect the new owners would be able to contact the old owners for help on this instead of sending a generalized call for help.

    • michaelt  7 hours ago

      According to [1] Yuasa battery date codes are year-month-day-plant/shift so 090323J0 indicates a battery from 2009.

      The building also was "out of operational use by Police Scotland for almost 10 years" and was purchased for community ownership earlier this year, according to [2]

      > If someone knew to replace the battery just three years ago, I would expect they also would have enough knowledge to set the clock itself.

      From the pictures, it looks like this clock needs to be manually changed on the last Sundays of March and October, for the start and end of daylight savings (they also need to be re-set any time there's a long power outage).

      This article is dated early April; it's possible the new community owners of the building (and clock) just needed someone to adjust it by an hour.

      The motor in the photo is probably a synchronous AC motor, where the rotation of the shaft matches the exact frequency of the AC supply. Then a long series of gears converts 50 rotations per second to 1 rotation per hour. Which avoids gradual clock drift - but without the fancy digital control needed to automate the daylight savings adjustments.

      Nowerdays, you can buy 'clock controllers' [3] that take care of daylight savings time etc automatically.

      [1] https://www.hardwarexpress.co.uk/pages/yuasa-date-codes [2] https://www.edinburghnews.scotsman.com/news/edinburgh-plans-... [3] https://www.hawkinsclocks.co.uk/clock-controllers

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    • fusslo  19 hours ago

      I would GUESS that someone tried figuring it out in 2023 and replaced the battery as troubleshooting. If it were me, I'd probably do the same then stop when I hit a wall so I didn't damage it further. I don't wanna be the guy who damages a 100+ year old public clock

      I could just hear the clockmaker James Martin calling me a butcher in his disapproving manner

  • icantevenhold  20 hours ago

    Could also be YYMMDD In most of Europe it would be DDMMYY - but seeing how the English still measure stuff in feet and inches I wouldn’t be surprised if they have some illogical way of structuring the dates as well

    • rmccue  19 hours ago

      YYMMDD is standard(ish) ISO 8601 - the new versions of the spec require a 4 digit year but older ones allowed it, and ISO 8601 is also commonly used in manufacturing.