motion sensor lights/ outside

thorsnessthorsness Solar Expert Posts: 52 ✭✭✭
Up at our cabin (90 miles north of Anchorage, Alaska) , we have a modest solar panel (1) two battery, 2000W Honda generator system which we use mainly for lights. In the winter we supplement the solar with the generator and charge the batteries with it as well. My question is: if I install motion activated floodlights on the porch and the trail to the outhouse, does it draw power from my batteries, even when the lights are not activated? Thanks.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: motion sensor lights/ outside

    The short answer is yes, IR motion detectors to use power to work (they are not passive devices).

    The longer answer: A properly designed motion detector does not use very much power... So, you would want to find a detector that is designed for low powered/battery operation rather than just an 120 VAC version that plugs into the wall.

    For example, a quick search found:

    http://www.absoluteautomation.com/dakotaalert/wir3000/index.html

    It will run on a 9 VDC transistor radio battery for 12 months. There are not any details on how you connect it to your load--and this version would have to be protected from weather (says indoor use). Price seems pretty expensive (I don't know anything about this product or company).

    I have also gone to Home Depot and purchased a self-contained security light (solar panel, motion detector, and two halogen lamps). You might try buying one of these to take apart/convert for your own needs (use the motion detector, change to LEDs to save power, possibly toss the solar panels and batteries to connect to your DC power system--might need a small regulator to match voltages--even a simple "3-Terminal regulator" might work fine (drop from 14 VDC to 6 VDC--if that is the working voltage of the motion sensor) as there is very little current requrement to begin with (so it costs you 4 watts per year to run the motion detector instead of two watts).

    My waring is that I have found most of these motion detectors only run for 1-3 years before they need replacing (poor design and/or weather proofing)... I would buy cheap and do your experiments first before spending too much money. Or get a good brand with warranty and service you can trust.

    More searches found:

    The following uses a 15 watt bulb, convert to 0.2-2 watt LED to save power!

    http://www.smarthome.com/740121.html

    Here is a $28 Motion Controller Kit (may be a bit too much work if you are not into this hobby):

    http://www.hobbyengineering.com/H1241.html

    Also, even Target sells a standard PR Flange Flash Light Bulb Frfrom Nite-Ize that is an LED with internal power supply--uses less than 1/10 the power of a standard 3 cell Mag Light bulb (will last ~100 hours on 3 D cell batteries and function on 2-5 C/D cells). They are not bright--but use a couple bulbs with dark adjusted eyes--and you should be happy.

    www.niteize.com

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: motion sensor lights/ outside

    Looking through Wind-Sun's store and found this 12 VDC motion detector (10 amp switch):

    http://store.solar-electric.com/inmotsen12vo.html

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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