19v on 18.5v input rail

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  • stevo1210
    Badcaps Legend
    • Oct 2006
    • 4156
    • Australia

    #1

    19v on 18.5v input rail

    Ive been getting a batch of various HP and Compaq laptops here for refurbishing. They are usually rated at 18.5v 3.5A or sometimes 4A.
    Now im not in the mood to buy chargers for every laptop that goes through here, would it be okay to use a 19v adjustable universal laptop psu by seasonic to power these units, install OS and do burn in tests? I havent had a problem using 19v on 18.5v laptops, but just wanted to be sure
    Don't find love, let love find you. That's why its called falling in love, because you don't force yourself to fall, you just fall. - Anonymous
  • Th3_uN1Qu3
    Believe in
    • Jul 2010
    • 6031
    • Romania

    #2
    Re: 19v on 18.5v input rail

    Nope, no problem. The difference is insignificant. As long as it supplies the required current (4A) it'll be fine.
    Originally posted by PeteS in CA
    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
    A working TV? How boring!

    Comment

    • b700029
      Banned
      • Sep 2010
      • 640

      #3
      Re: 19v on 18.5v input rail

      Agreed, a 2.7% higher voltage isn't going to do much.

      Probably all laptops these days have an internal DC-DC converter that takes a pretty wide input voltage range (from battery voltage, which is usually in the 14v range, up to ~20v.) The upper limit isn't going to be the converter itself since that's rated for ~30v, but things like 25v caps in the circuit.

      Comment

      • PCBONEZ
        Grumpy Old Fart
        • Aug 2005
        • 10661
        • USA

        #4
        Re: 19v on 18.5v input rail

        You're fine.
        A half volt is no problem there as long as the amps are good too.

        A whole volt probably wouldn't be a problem either.
        If you could get your hands on the Engineering docs....
        ... That 19v is probably actually something like 19 +/-1 volts.
        ... That 18.5v is probably actually something like 18.5 +/-1 volts.
        .
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        • stevo1210
          Badcaps Legend
          • Oct 2006
          • 4156
          • Australia

          #5
          Re: 19v on 18.5v input rail

          Originally posted by PCBONEZ
          You're fine.
          A half volt is no problem there as long as the amps are good too.

          A whole volt probably wouldn't be a problem either.
          If you could get your hands on the Engineering docs....
          ... That 19v is probably actually something like 19 +/-1 volts.
          ... That 18.5v is probably actually something like 18.5 +/-1 volts.
          .
          Okay, cool. Looks like I won't need to spend some extra cash on a new power brick designated for 18.5V then :P
          Don't find love, let love find you. That's why its called falling in love, because you don't force yourself to fall, you just fall. - Anonymous

          Comment

          • japlytic
            Badcaps Legend
            • Oct 2005
            • 2086
            • Australia

            #6
            Re: 19v on 18.5v input rail

            I got away with 19V on a Compaq Armada with an 18.5V input, and I don't know of any universal notebook adaptors which have a "half volt" option.
            My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

            Comment

            • Th3_uN1Qu3
              Believe in
              • Jul 2010
              • 6031
              • Romania

              #7
              Re: 19v on 18.5v input rail

              Originally posted by japlytic
              I don't know of any universal notebook adaptors which have a "half volt" option.
              I have one that does. Although, it does go from 16v straight up to 18.5v, and then 19v. Also, since a lot of the laptops coming in ask for 18.5v, i'm too lazy to flip the switch so i run my old Fujitsu on 18.5v too, and that thing is rated for 16v. It hasn't complained yet and it's been more than an year.
              Originally posted by PeteS in CA
              Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
              A working TV? How boring!

              Comment

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