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Laptop powering idea bounce

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  • Laptop powering idea bounce

    Got an old laptop I thought I'd give this a go with.

    Thoughts are to get a laptop car charger and hard wire it to the battery via a relay that'll only give power with the ignition. Laptop comes with a program to only charge it to 80% to help preserve it?

    Is there any reason this shouldn't be done? Could hard wire a switch before the relay for the long journeys.

    Now the next bit I couldn't find a definitive answer after a search.

    Centrafuse can put the laptop into standby, where it still loads up in a few seconds by pressing the power button - great.

    Pulse relay gets the computer on with the ignition, easy enough.

    So does Centrafuse have a function to be able to put the laptop in standby mode automatically with an input and how do you give it that input?


  • #2
    Also the relay for the charger.... How many amps does it need to be?

    Assume just a 4 pin - Power, ignition live, earth, and live out?


    • #3
      Have a look at this for one way
      For the relay a standard auto 30 amp relay should be more than enough


      • #4
        Lovely, cheers for the link. So just to confirm, if I just wire up the charger to the laptop via the ignition, when that is connected and disconnected that software will take over the rest?

        Then I just need to press the on button with the ignition or does it do that for you too?

        "Upon Resume...

        AC is restored > Loads any applications you specify to be loaded after resume > Resets status and preps computer for cycle"

        Will it still load up


        • #5
          i replied to your other thread, but have you considered using a dc-dc-usb, carnetix 1900, or carnetix 2140? they would take care of startup/shutdown, and charging, all while providing some easier terminals for powering.
          My OLD 2001 Mitsubishi Eclipse GT:
          "The Project That Never Ended, until it did"

          next project? subaru brz
          carpc undecided


          • #6
            blessani has impressed me!

            qwerty9 - your idea is fine and yes to Wozza's 12V 30A relay - unless you want something smaller - but the 30A is common, cheap, and uses common spade connectors.

            The only thing is that an off-delay is desirable - not only to ride thru successive cranks IF you have to turn off IGN between cranks - but to ride thru short stops such as refuelling, errands, nature...
            Hence options as above, but I like the thought of mere common & cheap relays and some user-configurable software...

            I usually add a manual bypass for on or charging whenever I want.


            • #7
              Cheers, I had a look at those types of supply and trying to find them or most things mentioned on this forum is difficult in the UK it seems.

              I did find this...


              Which to be fair looks like with a bit of playing could do most of the job easy enough. Will have to chop that lighter adapter and hard wire that, maybe to the ignition if there is no input for that. Mod the power button so it pulses that.

              A mate made a fair comment earlier about if it crashes etc, the place its going to live isn't accessible in seconds, so Id have to copy the laptop switch with a simple momentary switch on the dash somewhere so if it crashes I can hold that down to turn it off.

              As you say a charger on off switch needs to be wired in too.

              That software looks really good, though I should have read it properly "Please Note. You do still need a method to turn on the laptop in the first place - this software cannot turn on the computer. There are a few different techniques"


              • #8
                Is pulsing the laptop power switch with 12v rather than the 19v ok?


                • #9
                  The laptops power switch needs its contacts to be momentarily shorted not powered or if you have wake up on link setting you can use that....I just did the hardwired mod to the laptops power switch with a switch under the monitor, as I do a lot of short trips and dont want the system starting every time I start the car.
                  You setup what function this switch does in the power control panel in windows (mine set to power off if pressed) you can also setup what you want the system to do at different battery levels as a backup if the above software fails.. Then use the above software to put the unit into sleep mode or shutdown for anything in between (when at the drive in or parked with the girl friend )
                  Hardest thing is working out all the what ifs... like if you have the power supply on with the ignition circuit only, then you will be running on the laptops internal battery when the ignition is off or in accessory's position to prevent running from the car battery when the engine is off ect ect.