Dead 12V battery using DC remote

Discussion in 'Power Electronics' started by sbriar, Jul 29, 2016.

  1. sbriar

    Thread Starter New Member

    Jul 29, 2016
    I have a project that I use a 12 volt 7Amp battery (lead acid battery) a RC hobby battery.
    I bought a 12VDC 15A on/off remote relay kit to turn on and off two car sirens when I push the remote button.
    The unit is placed outside, I use the remote to turn on and off the sirens (from inside the house). maybe 3 seconds at a time.
    I have only used the remote around 10 times within a month to turn on and off the sirens before the battery went dead (about 3.6 volts when checked)
    My question is : I would have thought the battery would have lasted much longer, is the 12V remote draining the battery even when not pushing the button? or is this just the way it is when batteries are placed outside and not used enough?
    Thanks for reading, hope you can help on what I am doing wrong!
  2. Kjeldgaard


    Apr 7, 2016
    A little calculation gives:
    30 days, 24 hours ~ 720 hours.
    7 AH spread over 720 hours ~ 9.7 mA.

    So, if the above is true, then the battery may well be empty after a month.
  3. sbriar

    Thread Starter New Member

    Jul 29, 2016
    so the battery will go dead even though I am not using it? is the battery being drained from the remote?
    or does the battery just drain from sitting for a month?
    thanks for your reply!
  4. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
    The outside part of the remote has to be on all the time, waiting for you to push the button, and so it must draw some current from the battery.
    The button part of the remote will probably draw negligible current from its battery until you press the button, when it will spring into life.