Using laptop when no EHU and no inverter (1 Viewer)

Dec 28, 2015
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Hi . I know I’ve seen this before but I now can’t find the suggestions that were made

My laptop runs on 240v but the transformer changes 240v to 19v (I think)

So how can I go about running it with only 12v

It seems daft to me to use an inverter but I don’t really understand too much

So can anyone help please. I may not have explained too well but I hope someone gets what I mean
 

tonka

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Jul 2, 2008
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There are 12v to 18/19v convertors to run off a cigarette socket.. do a Google search 👍
 

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Tombola

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Nov 21, 2020
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I always used the 12v adapters like the post above but If its a fast powerful laptop like I have now you may struggle, I did with my 20v 7.5a ASUS.
In which case a smaller inverter may help that can plug onto the 12v socket.

I tried lots of the changeable ones, dedicated ones that said 20v, and I even asked ASUS who couldnt help with a 12v direct adapter info.
NOWT !!!

edit :: Just seen jims post above,and it lists ASUS ! I havent tried that one...might give it a go, i see it says 20v ( ihave tried em before that say this) and the adapter socket doesnt fit to lappy.

Jim what v is your lappy ? please

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cessac

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Oct 1, 2022
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Just brought one . Haven't tried it yet , but it seems a well made robust piece of kit. (y) (y)
 

hja

May 8, 2020
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Please excuse my total ignorance, but does the engine have to be running for the cigaret lighter ones to work?
 

Tombola

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Nov 21, 2020
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Please excuse my total ignorance, but does the engine have to be running for the cigaret lighter ones to work?
usually yes if you are using the ones in the cab.
If using the ones in the hab linked to the leisure batteries then no
 
Oct 12, 2009
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We have used one we got from Tandy years ago and it has worked well for our Acer laptop even now it is faster with an SSD drive.

We tether the laptop to the phone. Better set-up for me than using a phone or netbook.
 
Jan 26, 2017
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Please excuse my total ignorance, but does the engine have to be running for the cigaret lighter ones to work?
No, but some 12v outlets only work when the ignition is on.

I fitted a couple wired directly from the leisure battery (with a suitable fuse).

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Gellyneck

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Jun 5, 2014
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If you are going to get \ use a 12v to 19v power supply suggest you make sure it is a regulated one given the possible sensitivity of electronic equipment.
 
Dec 24, 2014
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Ever since lighting was by Calor gas.
No, but some 12v outlets only work when the ignition is on.
The cab cig lighter socket in my VW T4 based m/h is permanently live so as well as running stuff from it I plug my Halfords battery charger in there to charge the starter battery when the m/h is in my drive at home. I do the same with a cig lighter socket in the hab area which is connected to the hab battery. The sockets are also handy for checking the voltage of their associated batteries with a 5 quid plug-in tester.
1666887801052.png
 
Apr 27, 2016
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My laptop runs on 240v but the transformer changes 240v to 19v (I think)
The output volts will be on the power brick label. Also either the watts or amps. Once you know the watts you can calculate the amps, and vice versa. Watts = volts x amps. If the power is less than 100W then there will be plenty of choice for a 'laptop car adapter'.

The cigarette-lighter socket(s) in the cab area are quite likely only live when the engine is running. It's quite easy to fit some more, wired to the leisure battery with maybe an in-line fuse. It's one of the first mods people make to a motorhome. Very useful, especially as you can have USB car adapters to charge all the other stuff like phones, satnav, small battery packs etc. I also use them to plug in the compressor that tops up the tyres for the MH and the scooter. I don't expect you'll fit as many as I have (18 at the last count) but half a dozen would probably all find a good use.
 
Feb 27, 2011
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If you are going to get \ use a 12v to 19v power supply suggest you make sure it is a regulated one given the possible sensitivity of electronic equipment.
It is a boost converter and is thus by it's very nature regulated.

The downside of the cheaper ones is they may not have short circuit protection or reverse polarity protection so you have to be a bit more careful with them.

The biggest problem I found with cheap ones was thermals.

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Aug 19, 2013
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There are 12v to 18/19v convertors to run off a cigarette socket.. do a Google search 👍
I was just looking at the manual for one just such that I bought recently, and was surprised to see that it would need a minimum of 8.3 amps supply! I've used its predecessor for hours at a time!
 
Apr 27, 2016
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I was just looking at the manual for one just such that I bought recently, and was surprised to see that it would need a minimum of 8.3 amps supply! I've used its predecessor for hours at a time!
That's 8.3A on the 12V input, I presume. 8.3 x 12 = 100W. It probably wouldn't need that full 8.3A for hours. I guess it would fully charge a flat battery in a couple of hours. If you were running the laptop at the same time as charging it, that's when you'd use 8.3A. As soon as the battery is full, the amps demand would drop quite a lot.
 
Aug 19, 2013
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That's 8.3A on the 12V input, I presume. 8.3 x 12 = 100W. It probably wouldn't need that full 8.3A for hours. I guess it would fully charge a flat battery in a couple of hours. If you were running the laptop at the same time as charging it, that's when you'd use 8.3A. As soon as the battery is full, the amps demand would drop quite a lot.
Thanks for that. I'd only just read the manual and as often happens on this excellent forum, immediately after, saw this posting. i was confused about the high amperage quoted, and how that would work in practice. I had lost my previous device along with my stolen camper, so bought this to replace it.
 
Feb 18, 2017
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1986
Please excuse my total ignorance, but does the engine have to be running for the cigaret lighter ones to work?
Depends on the Van.

Many vans (Transits, Sprinters etc) have at least two cigarette chargers, one in the dash for lighting fags etc, which only works when the engine is on, and the other socket down at ground level by the gearstick, or inside the glove box which is directly connected and runs all the time (designed to power tyre pumps)

Other cigarette lighter sockets in the hab area run off the leisure battery.
 

hja

May 8, 2020
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Depends on the Van.

Many vans (Transits, Sprinters etc) have at least two cigarette chargers, one in the dash for lighting fags etc, which only works when the engine is on, and the other socket down at ground level by the gearstick, or inside the glove box which is directly connected and runs all the time (designed to power tyre pumps)

Other cigarette lighter sockets in the hab area run off the leisure battery.
thanks
 

Furry Paws

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Jul 7, 2021
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If you are going to get \ use a 12v to 19v power supply suggest you make sure it is a regulated one given the possible sensitivity of electronic equipment.
This also applies if using an Inverter, it must be a Pure Sine Wave one not Modified Sine Wave as they can damage sensitive electronic equipment!
 

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