Can low batteries in a motion detector trigger a false alarm?

Discussion in 'Shiny Things' started by LuciferMutt, Jul 29, 2013.

  1. LuciferMutt

    LuciferMutt Rides slow bike slow

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    I got a call this morning about 9:30 that my den motion sensor had triggered my security alarm. The company dispatched police and I raced home. Everything was fine, thankfully -- I'm still coming off the stupid adrenaline.

    Anyway, I called the alarm company to ask if they had any insight to what happened.

    Two things: 1: The den motion sensor is a wireless unit, and 2: my neighbors did NOT hear the alarm go off! The tech on the phone thought the lack of audible alarm was odd and had me test the system and it seemed to be working fine (alarm sounded and everything).

    I asked him if low batteries in the motion detector could be to blame and he said it would give me a trouble code but not set off the alarm (I get trouble codes from the fob batteries going dead about once a year so I know all about that).

    I have never replaced the batts in this sensor because I have never had a trouble code calling for it. The best answer the tech had was "wait and see if it does it again." :bluduh

    Some research has indicated that low batteries CAN cause a false alarm, but there seem to be very mixed opinions about this. Anyone have any insight?

    I have had this system for four plus years now and never had a single problem with it until now.

    Probably going to replace the batteries just on principle, BTW.
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  2. SourKraut

    SourKraut Long timer

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    Something fell off a shelf or shifted tripping the motion sensor. Or a bug landed on it.
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  3. Mknpwr

    Mknpwr Have you seen my bike?

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  4. Sniper X

    Sniper X De Oppresso Liber

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    It may, but chances are something triggered it. Thunder can do it, as can a big truck rolling by if it is on a wall that can vibrate. We have ours go off from time to time if a wasp or horsefly lands on it.
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  5. LuciferMutt

    LuciferMutt Rides slow bike slow

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    I'm genuinely curious; how does a vibrating wall cause a motion detector to trigger? Today was garbage day, and the new recycling trucks haul ASS down the street -- shakes the whole house.

    FWIW, these detectors are set up such that you usually need to take a few steps in front of them before the zone light comes on -- IE they are not super sensitive.
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  6. hpsVFR

    hpsVFR Hoosier Daddy

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    Is the strange part that the detector went off, or that the detector went off but didn't set off the audible alarm?

    There's lots of ways to set off even an insensitive motion detector (flying insects, vibrations, certain types of reflective surfaces, etc., depending on how the detector works), but if the detector is supposed to always trip the audible alarm, you've got something else strange going on.
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  7. LuciferMutt

    LuciferMutt Rides slow bike slow

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    Probably. Think I'm gonna call the alarm co and have them send a tech out to check things over.
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  8. Tmaximusv

    Tmaximusv Long timer

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    I used to work as an alarm monitor (my God what a horrible job!) for a small group of installers.

    Talking to techs, steer well clear of the battery powered anything detectors. JUNK and unreliable. Go read about how well your bike or car runs on a weak battery. I can tell you we had a few installers whose accounts we HATED because of the equipment they installed - constant false alarms.

    Next question, are your detectors passive IR or some other sort? PIR should only signal of there is a warm, large object moving in its field, not a bird, book or shaking house.

    Battery units are bargain basement so the techs don't have to run wire to install good equipment. You may want to see if your local PD has callout charges for alarm systems. Some municipalities get almighty cranky about the subject.

    In the end, a lot of customers just wanted the sign out front of their house and quit monitoring when the contract expired.
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  9. Speedo66

    Speedo66 Transient

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    Poltergeists. They're baaaaack.
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  10. LuciferMutt

    LuciferMutt Rides slow bike slow

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    :hmmmmm:yikes
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  11. Nytelyte

    Nytelyte Somewhere about

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    This... Most of the motions can be set off by weird things, a bug, something falling, heat / a/c triggering (if its a PIR).
    But from what you are describing, you had something go wrong on the board side. Interference, electrical blip, panel is starting to fizzle, odd ground, something goofy. You should test it by setting the system and then setting off that sensor just to make sure all is operating correctly. Or see what a tech says, see if he'll give you a full event log print (or show you the screen, we could never print on site).
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  12. LuciferMutt

    LuciferMutt Rides slow bike slow

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    Well, because of all the huge thunderstorms lately, the electricity has been blipping a lot lately, even in nice weather, while PNM switches things around after repairs. I did speculate at the time maybe the power surged or something but the main system board has battery backup power.

    Something to look into if I have any more problems. I did replace the battery in the detector. Also, in the process, I found some very fine cobwebs in that corner -- not full on webs, but just very light old stuff that you could feel more than see. Cleaned everything out of the way.
    #12