LED light conversion

Discussion in 'The Projects Forum' started by MartyL16, Mar 1, 2013.

  1. MartyL16

    Thread Starter New Member

    Feb 3, 2013
    I really would appreciate some help with this project.

    I have an undercabinet LED light fixture that runs on 3 AA batteries and activates by a motion sensor which is why I bought it.

    It has 12 white LEDS, the motion sensor and an ambient light sensor to keep it from activating during our daylight hours.

    Problem: with us and our dogs and cats, it goes thru batteries quickly.

    My proposed solution: I want to replace the alkaline batteries with rechargeable NiMH batteries and keep them charged with my new SWITCHMODE 4.5 VDC "wall wart" rated at 2 amps.

    The wall wart appears very stable at an almost constant 4.7 vdc.

    I believe the NiMH will be fully charged at 1.2 X 3 = 3.6

    Since I opened up this fixture and saw some "chips", I am guessing that they are for the ambient light and motion sensor control and the fixture is current regulated by the inherent current limitation of 3 AA batteries (in series) and voltage limited by the state of charge of the original 3 alkaline batteries in series ( 1.5 X 3 = 4.5 vdc).

    I am guessing that my above stated SW MODE PS will work fine but I would think that I am missing needed information to complete this project.

    Comments, ideas, explanations will be appreciated.
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    forget the batteries..just attach the wall wart to it on the output of the battery stack.
  3. w2aew

    Active Member

    Jan 3, 2012
    Even simpler solution - mask off part of the motion sensor so that the lights come on only when you create some movement on the counter, and not general traffic thought the kitchen. I have similar lights in my closet, and masked part of the motion sensor so that the light goes on only when I put my hand into the closet.