CLICK HERE TO REMOVE THESE ADVERTS


Page 1 of 2 12 LastLast
Results 1 to 10 of 18

Thread: Voltage / Inverters / Laptops

  1. #1

    Member Number
    77050
    Join Date
    Jul 2018
    Posts
    42
    Motorhome
    Knaus Boxstar Freeway 630

    Voltage / Inverters / Laptops



    CLICK HERE TO REMOVE THESE ADVERTS
    Hi,

    My laptop is beginning to refuse to charge when not on EHU.

    I was wondering if anyone has any insights into the problem. When new van happily powered inverter, wondering if the problem is likely to be with leisure batteries, inverter or even the laptop... Macs sometimes refuse to show the charging light even when plugged into the mains.

    thanks

  2. #2

    Member Number
    50391
    Join Date
    May 2015
    Posts
    3,946
    Motorhome
    see picture
    Running a laptop charger from an inverter is asking for trouble. You lose a lot of power (perhaps 25% or more) converting from 12v DC to 230v AC and as much again going back down from 240v AC to 19v DC or whatever the laptop needs.

    To get a typical 65 watts into the laptop, you are putting 87 watts into the adapter.
    To get 87 watts into the adapter, you are putting 116 watts into the inverter.
    To get 116 watts into the inverter, you are drawing 9.6 amps out of the battery.
    A sustained 9.6 amp load will reduce the voltage into the inverter.
    With a low voltage input, the inverter's output voltage may drop from the nominal 230 watts to something like 215 volts, which will upset a power supply designed for 240 volts input.

    You can easily tell how much power is being wasted: it is the heat coming off the inverter and the power supply adapter.

    A MUCH better approach is to use a proper 12v adapter for your laptop.

    They are usually no more than about £20 and are about 95% efficient. So that 65 watts output is only costing 5.7 amps of battery power.

  3. #3
    Nabsim's Avatar
    Nabsim is offline Full Member
    Name: Nabs (Neil)
    Spouse: Caz

    Member Number
    74742
    Join Date
    Feb 2018
    Posts
    2,181
    Location
    High Peak
    Motorhome
    Geist Phantom
    Quote Originally Posted by hairydog View Post

    A MUCH better approach is to use a proper 12v adapter for your laptop.

    They are usually no more than about £20 and are about 95% efficient. So that 65 watts output is only costing 5.7 amps of battery power.
    While this is true for most laptops it doesn’t necessarily follow for MacBooks, last time I checked for mine a generic 12v psu was around £90.
    Don't Worry, Be Happy
    Likes EarthDemon liked this post
    Thanks EarthDemon thanked for this post

  4. #4

    Member Number
    28193
    Join Date
    Aug 2012
    Posts
    1,502
    Motorhome
    Roadtrek 190V
    Well, what do you expect if you buy an expensive half eaten apple....
    Colin
    Warning: Definitely contains nuts.
    Likes trevskoda, Tezza33, ricc, Nabsim liked this post

  5. #5

    Member Number
    77050
    Join Date
    Jul 2018
    Posts
    42
    Motorhome
    Knaus Boxstar Freeway 630
    Quote Originally Posted by Nabsim View Post
    While this is true for most laptops it doesn’t necessarily follow for MacBooks, last time I checked for mine a generic 12v psu was around £90.
    Very glad I asked - any chance of a link to the sort of thing you are talking about?

    Also, perhaps I am misunderstanding this but I though we were stuck with inverters because macs run on 14V or thereabouts, hence the inverter.... That could be complete b*ll*x....

  6. #6

    Member Number
    60568
    Join Date
    Jun 2016
    Posts
    2,804
    Motorhome
    VW LT 2.8TDi Self-Build Camperbus
    anything to do with apples is always overpriced
    Find me on motorhomer.com, a Brexit-Free Zone
    Likes ricc liked this post

  7. #7

    Member Number
    5816
    Join Date
    Mar 2009
    Posts
    2,826
    Location
    South Yorkshire
    Motorhome
    VW T5 Auto-Sleepers Trooper
    We always had 2 apples and 2 oranges per child sent free at school just after the war.

    Alf

    Quote Originally Posted by wildebus View Post
    anything to do with apples is always overpriced
    Likes trevskoda, Tezza33 liked this post

  8. #8

    Member Number
    25133
    Join Date
    May 2012
    Posts
    15,085
    Location
    Glengormley
    Motorhome
    iveco iris lib bus
    Quote Originally Posted by Alf View Post
    We always had 2 apples and 2 oranges per child sent free at school just after the war.

    Alf
    Did someone mention orange,it was old but it was beautiful and the colours they were fine and it was on the twelth i used to sing the sash my father wore.
    Only dirty people wash
    Likes Alf liked this post

  9. #9

    Member Number
    21340
    Join Date
    Nov 2011
    Posts
    3,681
    Motorhome
    Sprinter
    Bought 12volt mac charger years ago, definitly wasn't more that £30. Loads around now, this ones similar. I make sure it charging while driving.

    85W Car Charger for Apple Magsafe 1 Macbook Pro A1172 A1175 A1189
    Thanks EarthDemon thanked for this post

  10. #10

    Member Number
    5407
    Join Date
    Feb 2009
    Posts
    9,823
    Location
    Derbyshire
    Motorhome
    Hymer 584 Classic
    Quote Originally Posted by wildebus View Post
    anything to do with apples is always overpriced
    They are expensive, as my Mum used to say, "they don't grow on trees you know"
    Likes mark61 liked this post

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •