davidfox
Well-Known Member
Is it better/more power efficient to run a laptop off of the 12v ciggie socket adaptor that comes with it or plugged into a 300w invertor or does it not matter?
Power supply to laptop
- Thread starter davidfox
- Start date
Conrad
Well-Known Member
The 12v ciggie socket should be the most efficient, the other way the 12v is converted to 230volts AC which inevitably loses and uses a bit of power in the conversion, then this is converted back to dc by the plug in power pack which again uses and loses a bit of power in the conversion process.
With the ciggie lighter there will only be one conversion which not having to go to 230 mains at 50Hz will be far more efficient.
With the ciggie lighter there will only be one conversion which not having to go to 230 mains at 50Hz will be far more efficient.
davidfox
Well-Known Member
Thanks
PIGLETSDREAM
Well-Known Member
I have run my Toshiba Satellite pro for about 5 years straight from a 12volt supply and without its battery(its knackered). No problems to date. Windows 98, tide planner from Danny on the forum and sea pro lite.
djh1962
Active Member
Hi ,
see RS you can get a 12V ciggy convertor to run your laptop, not many off them are 12V supply, will do most types.
see RS you can get a 12V ciggy convertor to run your laptop, not many off them are 12V supply, will do most types.
davidrainsbury
Active Member
I run mine direct from 12v too. Running a laptop from an invertor is not a good idea for more reasons than efficiency though. The AC that you get from the invertor is not always true AC but a sort of simulated version (an oversimplification if ever there was one). This works fine for most things but can play havoc with electronics.
Piddy
Well-Known Member
My old Dell cigarette lighter adaptor didn't like it if the engine wasn't running (charging) and made strange noises which I didn't like. I put it down to the normal operation in a car, which would normally be running.
A lot of cigarette lighter plug sockets aren't designed to hold the plug in place and when one wobbled loose, it created a poor connection and heated the plug up - a lot!
I fitted a good sized, pure sine wave inverter and wired it to a socket by the chart table and plug the normal charger into that. No problems.
I do take the laptop batteries out once they are charged as (thanks to the advice of SBC) it then only provides enough power to run the computer and not the charging system.
Cheers
A lot of cigarette lighter plug sockets aren't designed to hold the plug in place and when one wobbled loose, it created a poor connection and heated the plug up - a lot!
I fitted a good sized, pure sine wave inverter and wired it to a socket by the chart table and plug the normal charger into that. No problems.
I do take the laptop batteries out once they are charged as (thanks to the advice of SBC) it then only provides enough power to run the computer and not the charging system.
Cheers
mainmarine
Well-Known Member
you can get them from Maplins, for around £20 mine has various voltage outputs and runs my Vaio at 19.5 volts
Haven't-a-Clue
Well-Known Member
Snap! Got mine from Maplins too. A word of advice given me by the tecchie at the shop; If yer laptop operates at a voltage not shown as available on the Maplin's thingy( ie my HP requires 18.5v) DON'T try the next voltage UP 19v f'rinstance, use the next voltage DOWN ie 18v. The tecchie was VERY insistent about this, in fact he said it 3 times! so I guess it's important.
BlueChip
Well-Known Member
[ QUOTE ]
I run mine direct from 12v too. Running a laptop from an invertor is not a good idea for more reasons than efficiency though. The AC that you get from the invertor is not always true AC but a sort of simulated version (an oversimplification if ever there was one). This works fine for most things but can play havoc with electronics.
[/ QUOTE ]
Apart from that, do you really want 240VAC around when you are at sea, with all the potential health risks that might cause?
I run mine direct from 12v too. Running a laptop from an invertor is not a good idea for more reasons than efficiency though. The AC that you get from the invertor is not always true AC but a sort of simulated version (an oversimplification if ever there was one). This works fine for most things but can play havoc with electronics.
[/ QUOTE ]
Apart from that, do you really want 240VAC around when you are at sea, with all the potential health risks that might cause?
mikejames
Well-Known Member
The only problem with going from 19 volts in down to 12 volts or 13.8 is that not all laptops can charge batteries at the lower voltage : the battery charger will step down to 14.4 or 9.6 volts (4 or 3 cell Li-Ion packs ).
The other thing is that the laptop will keep on pulling the same power from the supply . So my 19 volts at 3.5 amp laptop will be pulling 5.5 amps from 12 volts .
This may overload some components in the laptop..... but probably not.. especially on low powered machines.
The other thing is that the laptop will keep on pulling the same power from the supply . So my 19 volts at 3.5 amp laptop will be pulling 5.5 amps from 12 volts .
This may overload some components in the laptop..... but probably not.. especially on low powered machines.
mainmarine
Well-Known Member
try taking the battery out and just powering it from the 12v supply
Amulet
Well-Known Member
Maplins 12v in to variable out works for me too. Vaio main laptop and a dell backup (different voltage but no probs).
Tried my Dell from an inverter and it went mental. Cheap inverters deliver square rather than sine wave, and it seemed to think it was going on and off charge 50 times a second.
If like me you sail everywhere and never charge your batteries you'll be worried about draining them with your laptop. When you're plugged into your 12 v charger your machine thinks it's on mains and will by default adopt a greedy power regime. You can adjust this and should - dimming the screen, spinnning down disk drives etc. I can cut my power consumption by 60%.
Tried my Dell from an inverter and it went mental. Cheap inverters deliver square rather than sine wave, and it seemed to think it was going on and off charge 50 times a second.
If like me you sail everywhere and never charge your batteries you'll be worried about draining them with your laptop. When you're plugged into your 12 v charger your machine thinks it's on mains and will by default adopt a greedy power regime. You can adjust this and should - dimming the screen, spinnning down disk drives etc. I can cut my power consumption by 60%.
Bav34
...
I like the sound of this.
Are you all saying that for about 20 squids Maplin will sell me a device that plugs into my 12 volt ciggie socket and will then somehow plug into my Acer laptop (which runs off a 14.8 volt 2000 mAh battery) ... and providing I turn down the power settings .... that's it??????
Sounds far too simple /forums/images/graemlins/ooo.gif
Have whizzed around their site ... can't see it. Anyone got a link or part number?
Cheers
Are you all saying that for about 20 squids Maplin will sell me a device that plugs into my 12 volt ciggie socket and will then somehow plug into my Acer laptop (which runs off a 14.8 volt 2000 mAh battery) ... and providing I turn down the power settings .... that's it??????
Sounds far too simple /forums/images/graemlins/ooo.gif
Have whizzed around their site ... can't see it. Anyone got a link or part number?
Cheers
Jonny_H
Well-Known Member
Haven't-a-Clue
Well-Known Member
Well, the one Johnny H highlighted is the one I bought and it works fine on my laptop, I obviously bought it at the wrong time, 'cos it cost me more than that!
barnaclephill
Well-Known Member
I've bought one of the 12V to various (15 to 24v) oval shaped converters, I suppose similar to the cheaper one mentioned above. Input voltage 12.0 to 13.8, output to 3.5 amps.
It works fine in the car, as the alternator is running, but the alternator doesn't often run in the yacht (use a 40W solar panel primarily). When the house batteries (300 Ahr) lose some voltage, the computer will scream with the power and running lights flashing and the intermittent buzzer/scream making it imposible for the boy to watch a DVD.
That was also the case when going through the 300W inverter, it could scream, but the 600W inverter doesn't.
I shall have to try the power-saving mode and removing it's kaput laptop battery and see if those things help.
It works fine in the car, as the alternator is running, but the alternator doesn't often run in the yacht (use a 40W solar panel primarily). When the house batteries (300 Ahr) lose some voltage, the computer will scream with the power and running lights flashing and the intermittent buzzer/scream making it imposible for the boy to watch a DVD.
That was also the case when going through the 300W inverter, it could scream, but the 600W inverter doesn't.
I shall have to try the power-saving mode and removing it's kaput laptop battery and see if those things help.
VicMallows
Well-Known Member
Check out EBay. I got a 70W convertor switchable to numerous voltages and complete with a host of interchangeable power tips. About £12.50 (inc post) from a retailer in Guernsey.
Vic
Vic
