12v laptop adaptor

[goldtone]

I bought a 12v laptop adaptor from amazon, but it doesn't seem to work on the boat.

 

When I plug it into the laptop, the icon showing I have a power source comes on for approx 4-5 secs, then goes off, reverting back to battery power. It's really bloody annoying as the laptop is my source of all entertainment and I hate having to use the 240v inverter to invert 12v - 240v - 19v. It seems such a waste of power.

 

Any one had this experience and know how to rectify it?

[alan_fincher]

I bought a 12v laptop adaptor from amazon, but it doesn't seem to work on the boat.

 

When I plug it into the laptop, the icon showing I have a power source comes on for approx 4-5 secs, then goes off, reverting back to battery power. It's really bloody annoying as the laptop is my source of all entertainment and I hate having to use the 240v inverter to invert 12v - 240v - 19v. It seems such a waste of power.

 

Any one had this experience and know how to rectify it?

If it's a fairly reputable adaptor it should work.

 

I'm just checking, but you are not using it at the end of a long run of not very substantial 12 volt cabling, are you ?

 

Although it will not be drawing big currents, I'm just wondering if voltage drop could be an issue - are you really sure you are feeding it with "12 volts", (which usually implies more than 12 volts in boat and car electrical systems).

 

AS an independent check, does it work if you use it in a car ?

 

If yes, it's something about your boat supply - if no, send it back to Amazon.

 

There are products that will deal with undervoltage on the supply, but I suspect some of the cheaper ones may not.

 

Alan

[Bullfrog]

Hey Alan

 

It's good to see you back on line too!

 

Hope you've not been the same place as Snibble!

 

regards

 

David

[alan_fincher]

Hope you've not been the same place as Snibble!

I don't know - I wouldn't know how to recognise him !

 

(Clearly this is a reference to some forum malarky that I'm not up to date with, yes ?)

 

Alan

[Bullfrog]

I don't know - I wouldn't know how to recognise him !

 

(Clearly this is a reference to some forum malarky that I'm not up to date with, yes ?)

 

Alan

Snibble's not posted for ages either and he has returned with excuse as here:-

 

http://www.canalworld.net/forums/index.php...st&p=224121

 

 

And careful about Malarky 'cos we've got a poster called that now!

Edited April 16, 2008 by Bullfrog

[alan_fincher]

Snibble's not posted for ages either and he has returned with excuse as here:-

 

http://www.canalworld.net/forums/index.php...st&p=224121

 

 

And careful about Malarky 'cos we've got a poster called that now!

Ah, I see...

 

Clear as mud!

 

I did notice on my first foray back some "heated" debate about how alternators do and dont work in a boat environment.

 

So nothing has really changed then!

 

Alan

[Scotty]

When I plug it into the laptop, the icon showing I have a power source comes on for approx 4-5 secs, then goes off, reverting back to battery power.

Sounds similar to my universal charger which has a selection of plugs, it turned out i was using the wrong connector plug and it was only just making contact, I tried another plug which looks very similar but it made a much better connection.

[Ray]

Does the adaptor you purchased have the required voltage output - I assume that you need 19 volts from the reference to that voltage in your post, and does the adaptor deliver enough current to drive the laptop?

 

I seem to recall that someone indicated on here a while ago roughly what current would be needed for the average laptop.

Edited April 16, 2008 by Ray

[Peter R]

I hate having to use the 240v inverter to invert 12v - 240v - 19v.

 

That's what I do - Has it occurred to you that that is probably almost exactly what your 'laptop adaptor' is doing anyway?

 

How much power does the laptop take? Mine's about 120W, which translates to about 10A at 12V - have you checked the rating of the cable feeding the 12V socket you're plugging it into.

 

Also check the rating of the adaptor, vs power requirement of laptop - symptoms suggest it could be the laptop pulling too much power for the adaptor causing the overload protection of the adaptor to shut it down.

 

Peter

[AjW]

I had a similar problem but the charger would cycle between on and off every 2 seconds; caused by the voltage drop over 25ft and the 10Amps being pulled by the power supply. I beefed up the wiring which partially did the trick. I now run the laptop off an inverter at the back of the boat because it is less sensitive to the 12V input - the 12v adapter is (I think) designed for use in cars where the supply is 13v+.

Most newer laptops will unashamedly demand 100W+ and if looking for a computer to use on a boat there are lower power options available than a laptop, such as in-car computers, VoomPC and uITX which will draw less than 50W!

[larkshall]

Your problem is a sensitive 12v adaptor, minor voltage fluctuations are causing it to drop out, have the same problem with mine. I put a trace on and scoped that mine will shutdown at 12.1v and/or 13.8v +/- .2v.

 

Why?, could be other devices cycling on or off.

 

I modded my adaptor, which is ok if you know what you are doing. The real cure would have bee to increase cable diameter, and sort out the fridge!!!.

[Chris Pink]

Worth noting cigarette lighter sockets are only rated up to 8A and i wouldn't trust them over about 4A.

 

Worth replacing with something more robust for any proper use. See if the plug gets warm (one i had melted)

 

12V is much more sensitive to dodgy connection than 240V AC.

 

100W for a laptop - tuesk!!

[Goldberry]

Easiest thing I found is to take the laptop and original power cable to Maplin Electronics and they will sell you the right thing!

[Sheepshank]

I've been looking around for a new laptop in preparation for use afloat. Most mid-range laptops seem to want 19 or 20 volts and 3.5 to 5.5 amps. That's a power use of between 65 and 110 watts. Does anyone know of a laptop/notebook that runs off 12volts, to save converting up? Preferably with a low power rating?

[Alistair]

I've been looking around for a new laptop in preparation for use afloat. Most mid-range laptops seem to want 19 or 20 volts and 3.5 to 5.5 amps. That's a power use of between 65 and 110 watts. Does anyone know of a laptop/notebook that runs off 12volts, to save converting up? Preferably with a low power rating?

 

Have you considered an eeePC?

[smileypete]

I've been looking around for a new laptop in preparation for use afloat. Most mid-range laptops seem to want 19 or 20 volts and 3.5 to 5.5 amps. That's a power use of between 65 and 110 watts. Does anyone know of a laptop/notebook that runs off 12volts, to save converting up? Preferably with a low power rating?

 

I had a Toshiba with 15V DC input which ran happily straight off 12v. It might not have charged it's battery in doing so.

 

Can be risky though, as starting/running the engine generates big voltage spikes that can damage the laptop, if connected directly.

 

A second hand Pentium 3 laptop shouldn't be too expensive or thirsty on power, though at least 512MB memory is needed for XP to run reasonably well.

 

cheers,

Pete.

Edited May 11, 2008 by smileypete

[Sheepshank]

Thanks Pete for the warning about the spikes - I've got a bit to learn yet. I'll probably carry on with my old HP pavillion, only uses 3.5A.

 

Saw this 12volt - 20v gadget while surfing - anyone tried it?

 

http://www.laptopshop.co.uk/laptop-noteboo.../spscarcord.htm

 

Adrian

[RobinJ]

I bought a 12v laptop adaptor from amazon, but it doesn't seem to work on the boat.

 

When I plug it into the laptop, the icon showing I have a power source comes on for approx 4-5 secs, then goes off, reverting back to battery power. It's really bloody annoying as the laptop is my source of all entertainment and I hate having to use the 240v inverter to invert 12v - 240v - 19v. It seems such a waste of power.

There can be problems with phone chargers because of different battery types, but with a laptop, provided the voltage is right it should only depend on current.

Have you checked exactly what the laptop requires - typically 19V at 6A. Can the adaptor supply it? Do you have a voltage drop on your 12V supply?

[pog]

Hi,

I bought a similar one of these from Maplins (the 70w, 3.2A version), but it broke.

It got really hot and melted (I only noticed when the charge light on the laptop went off).

I took it back thinking maybe it was broken or wasn't powerful enough for the job (although I had checked with the shop when I bought it).

Maplins kindly swapped it for the higher power one (160?w, 8A) as this was reduced at the time.

My laptop only draws 65w and 3.12A.

This one then got really hot, so I stopped using it.

I tested it in my van and it worked fine.

Then I took a multimeter to it! My boat socket was giving out 11.2V, my van socket over 13V.

I then checked my batteries and they are flat. I then started the engine and the alternator seemed to be charging them OK.

 

Am I right in thinking that the input voltage from my boat socket is too low, making the charger try to work too hard, then dying?

As you probably gathered from the above I'm not too good at electrics...

 

If its a voltage drop on the wires to the socket (no markings but look quite thin) then I take it I need a new socket wiring up?

 

Any ideas for how best to fix this as I bought the charger so I wouldn't have to use the invertor to run my laptop.

 

Thanks for any help that can be offered!

[Chris Pink]

Then I took a multimeter to it! My boat socket was giving out 11.2V, my van socket over 13V.

I then checked my batteries and they are flat. I then started the engine and the alternator seemed to be charging them OK.

 

Am I right in thinking that the input voltage from my boat socket is too low, making the charger try to work too hard, then dying?

 

 

The 11.2V i assume is with the laptop running, otherwise your batteries are dead.

 

The 11.2V is the result when drawing that amount of power. Measurement with no load is the only way of estimating battery state-of-charge. if below 12V you should be thinking of recharge or at least not running high current devices

 

so; remedies

 

yes, cabling is an issue, distance counts but fat cable close to the battery is favourite. if a cigarette lights socket then make sure it's a good one and clean, they're not really up to laptop currents.

 

if the battery is aged a new one will definitely help. Especially with winter coming a good time to check you have the capacity for what is one of the hungriest power demands.

 

4 hours of laptop in the evening is around 20Ah so make sure you are generating and capable of storing that capacity.

[Priston]

I bought a 12v laptop adaptor from amazon, but it doesn't seem to work on the boat.

 

When I plug it into the laptop, the icon showing I have a power source comes on for approx 4-5 secs, then goes off, reverting back to battery power. It's really bloody annoying as the laptop is my source of all entertainment and I hate having to use the 240v inverter to invert 12v - 240v - 19v. It seems such a waste of power.

 

Any one had this experience and know how to rectify it?

 

I had a similar problem with a small inverter I had purchased some time ago. My problem was that the inverter was too small for the laptop. Check the rating of the inverter and the rating of the laptop, you would be quire surprised the power required of the laptop. Remeber volts multipled by amps equals watts.

[bottle]

I had a similar problem with a small inverter I had purchased some time ago. My problem was that the inverter was too small for the laptop. Check the rating of the inverter and the rating of the laptop, you would be quire surprised the power required of the laptop. Remeber volts multipled by amps equals watts.

 

 

Standby incoming !!!!!

[twocvbloke]

 

Standby incoming !!!!!

 

DC voltage is definitely VxA=W, it's AC you've got to don the tin hat for...

[pog]

The charger is definately big enough for the laptop.

Charger is rated up to 160W and 9A, laptop only draws 65W and 3.12 at 19v.

Think is either the batteries or the socket, then.

The charger does work fine in my van.

Am going to do best to recharge the batteries (hoping they are not dead as only about 3 months old), then if there's still a problem it's got to be down to the wiring/socket.

Unless I've missed anything?

[Chris Pink]

Am going to do best to recharge the batteries (hoping they are not dead as only about 3 months old), then if there's still a problem it's got to be down to the wiring/socket.

 

Best is to try a short length of flying lead connected straight to the battery.

 

After, of course, making sure the batteries are reading 12.4V or more with no load.

 

I would suggest for example a 5m run you want to connect socket to battery using 6mm² cable. Make sure plug and socket is a tight fit and that the connections to it are sound.