The Notebook Review forums were hosted by TechTarget, who shut down them down on January 31, 2022. This static read-only archive was pulled by NBR forum users between January 20 and January 31, 2022, in an effort to make sure that the valuable technical information that had been posted on the forums is preserved. For current discussions, many NBR forum users moved over to NotebookTalk.net after the shutdown.
Problems? See this thread at archive.org.

    Inverter versus DC to DC converter

    Discussion in 'Accessories' started by CF30Medic, Sep 17, 2018.

  1. CF30Medic

    CF30Medic Notebook Enthusiast

    Reputations:
    0
    Messages:
    21
    Likes Received:
    8
    Trophy Points:
    6
    i looked several places for an answer to this question and couldn’t find one, so I did a little experimenting.

    The question is: How much more efficient is a dc-dc adapter versus going from 12 volts to 120 volts through an inverter, and then back to laptop voltage through an ac charging cord?

    I have a Panasonic CF-30 Mk3 Toughbook, a 150 watt dc to ac modified sine wave inverter, a Lind dc to dc converter, and two ac charging cords, one OEM Panasonic and one cheap ebay charger.
    I tried them all together and here’s what I found out...

    Charging the laptop from a 50% discharged laptop battery with the unit turned off...
    Panasonic Charger with inverter 3.0 amps
    Cheap charger with inverter....also 3.0 amps
    Lind dc to dc: 2.5 amps

    Laptop turned on and “thinking”...ie hard drive running, processor processing:
    Panasonic ~4.5 amps
    Lind: ~4.2 amps
    Hard to get a solid number because the amperage jumps around a lot.

    Laptop on but idle:
    Panasonic: not tested.
    Lind: 3.0 amps

    The difference is pretty insignificant if you’re charging from your car, but charging from a battery pack or from a solar power system a half an amp can make a big difference.
    Hope that helps.
     
    CF30Medic, Sep 17, 2018
    #1