power for laptop

[jonic]

Dear all,

Which inverter in wattage terms do I need to power a laptop? What items require more juice, and who is a good supplier? Sorry I know this is very dull.
Moonshine is now on the hard, mast down waiting for her holding tanks and sunsucker gantry.

Gracis

http://web.ukonline.co.uk/yacht/serafina/

 

[ccscott49]

Have a look on the bottom of the present transformer you have, it will tell you the input voltage, current and probably wattage, if it doesnt tell you the wattage, simply multiply the voltage by the amps and thats the wattage, I would go for 100% more than required. If you have a printer, do the same thing and thinkl about the phone recharger, but you probably have a car charger for that anyway. Most of the chandlers these days have inverters. Just as an aside, do the computer manufacturers not have a car charger for your computer? most modern ones do supply one, that would solve that problem.

 

[robp]

This came up a couple of months or so ago. A search would be useful. However, laptop car chargers are more expensive than small invertors but probably draw a little less from the batteries. They are of course then exclusive to the laptop too. (Mine is 19 Volt and cost £69). A 150 Watt invertor should suffice.

 

[jfkal]

Do not use an inverter. This way you waste energy two times. Check the required voltage if it is in the range of 12-15V hook up straight to the DC system. If it is lower use a voltage regulator ie. 7805 7809 7812 with an ample heatsink.

 

[kdf]

All laptops (last 4-5 years anyway) will work just fine on 12v so you can use the cig lighter connection if you have one. If you want to charge the batteries then you can get a DC- DC converter which will supply 14v off a 12v line. I got one from Teleadapt for about $50 and it works great on my Toshiba.

 

[rogerm]

As someone else says it is more economical (on the battery) to use a 12v adapter. It is not always possible to connect 'straight thru' but might be if the voltage is 12-15v. However quite a few laptops use around 18v which needs an adaptor of some sort.
If you don't mind using an everyday (non-marinised) item then have a look at www.cpc.co.uk. They do several inverters (if you want to be able to run other things as well eg printer) as well as 12v adaptors and are loads cheaper than chandlers. Don't get an inverter thats lots bigger than your needs as they can be wasteful if underrun.
Roger

 

[robp]

Plus, the larger ones are fan cooled which will take even more power.

 

[jonic]

thanks all for the info , all very useful.

http://web.ukonline.co.uk/yacht/serafina/

 

[tgalea]

hi,

regarding the "power for laptop" issue. I have a standard 220-240 volts A.C. adapter which comes with my laptop for home use.

So what is it exactly you can do ? sorry but haven't understood what you mean when you say use the cigarette lighter outlet. You still need to buy some Cigaretter Lighter kit for the laptop, yes ?

Cheers

Tyrone.

 

[kdf]

You don't use the 220/240 volt adapter - Instead you get the Teleadapt DC supply unit - you pick the one for your laptop when you order (different power connectors) and plug one end into the laptop and the other end has a cigarette type plug - assuming you have one of these outlets on your boat you just plug it straight in.

This gives you up to 15 volts which is fine for charging your laptop - heat output is minimal and it appears to be very efficient.