Running a Laptop Without an Inverter

[gmau]

Originally Posted by Weyalan

Given the power losses with converting DC to AC and then the losses with converting it right back to DC again, I have never been a big fan of using an inverter to run a laptop.

My previous laptop would run quite fine from a standard 12V DC cigarette-lighter type outlet using a DC-DC adaper, with adjustable output, so I would just set it to the required voltage (16V, from memory) and off we'd go.

My new laptop, apparently, has some sensor in the power inlet and won't allow me to do this. So at this stage a small (150W) inverter looks like the only solution...

Any alternatives?

I've had terrible luck with 12VDC inverters. Blew up a Dewalt charger. Couldn't get the inverter in an Toyata Avalon to work. For the boat, I don't use the Xantrex 1000. I got a computer grade 400 watt. Runs the laptop, and all the other 120VAC chargers. Needed one for the car so I got one at DC Auto Power. It was about $20. Works great.

My opinion is don't waste your money and buy a pure sine wave inverter.

Gordon

[rebel heart]

I'd vote for the pure sine wave inverter. There are some portable ones (read: no install) that look good. We have this one (not a pure sine wave):

Amazon.com: Duracell 813-0291-07 175 Watt DC to AC Pocket Power Source Inverter: Patio, Lawn & Garden

It works fine for running our Asus netbook, but my IBM W500 laptop kicks and screams, flipping between charging and not charging every couple of seconds. So for us, that's okay, because we just use the netbook on board and the cost associated with another inverter just isn't really justified.

I've seen (first hand) problems from 12v adapters for laptops. Your laptop is expecting (via its power source / AC-DC inverter) to have a rather exact DC power. Most boats will never be able to provide that level of stable DC voltage. The less than a half an amp difference by using an DC->AC inverter and then your laptop's AC->DC converter can greatly extend the life of your laptop.

It's all device dependent though. Like I said, the Asus works fine on the above inverter, and the IBM throws a tantrum.

[Unicorn Dreams]

Why not just get the car charger designed for that laptop..

[Troubadour52993]

I'm with Unicorn Dreams, I run my Dell laptops that require 19V from LIND power supplies. They come with cigarette lighter or hardwire pigtails for the 12V supply and the correct connector cord for your laptop. They have numerous models for various computers, and it's worked for me so far. If you run the battery down to red, they don't have the juice to keep the laptop working and charge the battery (you have to shut down), but otherwise they keep up great.

Look for them on eBay auctions if you don't want to pay retail.

[SV Demeter]

I am trying to find a "car charger" for my laptop but am not having much luck so far. I currently use the inverter to run the laptop but would prefer to go to a DC source. I have a Gateway FX series laptop whose power supply says 19.2 Volts DC 6.4amps I believe. Went to best buy and they just wanted to sell me an inverter did not understand what i was looking for. When I try the online stores none seem to recognize my "FX" series. The all suggest MX and other Gateway series. Perhaps someone here with bettter search skills can point me to a DC laptop plug for my FX series Gateway?

Also was out on the boat yesterday and tried charging my iPhone via the AC plug and inverter. It was not enough draw to kick on the inverter so will stick to DC charger there too.

[Pete7]

Originally Posted by Troubadour52993

I'm with Unicorn Dreams, I run my Dell laptops that require 19V from LIND power supplies. They come with cigarette lighter or hardwire pigtails for the 12V supply and the correct connector cord for your laptop. They have numerous models for various computers, and it's worked for me so far. If you run the battery down to red, they don't have the juice to keep the laptop working and charge the battery (you have to shut down), but otherwise they keep up great. Look for them on eBay auctions if you don't want to pay retail.

I found that my 19v Dell laptop used 4 AH from the house bank when using the mains charger through an inverter, but only 2AH when using a car charger.

Pete

[noelex 77]

Originally Posted by rebel heart

I've seen (first hand) problems from 12v adapters for laptops. Your laptop is expecting (via its power source / AC-DC inverter) to have a rather exact DC power. Most boats will never be able to provide that level of stable DC voltage. The less than a half an amp difference by using an DC->AC inverter and then your laptop's AC->DC converter can greatly extend the life of your laptop.

DC to Dc converters will not shorten the life of your notebook. The converter is designed to provide a stable voltage so fluctuations in the boat battery voltage will not effect the output.
Just make sure you have a suitable model for your laptop and if its adjustable that the voltage and polarity is correct.
The power savings compared with an inverter depend on a lot of factors, but 20 to 30% less power draw is typical.

[SV Demeter]

Originally Posted by noelex 77

DC to Dc converters will not shorten the life of your notebook. The converter is designed to provide a stable voltage so fluctuations in the boat battery voltage will not effect the output.
Just make sure you have a suitable model for your laptop and if its adjustable that the voltage and polarity is correct.
The power savings compared with an inverter depend on a lot of factors, but 20 to 30% less power draw is typical.

Where is a good place to purchase said DC to DC converter? Specifically looking for 19.2 volts? Linky please.

[Pete7]

Originally Posted by SV Escape Plan

Where is a good place to purchase said DC to DC converter? Specifically looking for 19.2 volts? Linky please.

Mine came from Amazon.

Pete

[Music]

I use them at work all the time in my designs. There are many brands and places to buy. Try Allied Electronics, Mouser Electronics, Newark supply, maybe even all parts. For 19.2vdc I would buy a 20 volt output and adjust it down in voltage.

[twistedtree]

iGo makes chargers that run off AC and/or DC depending on the model. They also have inter changeable tips so they can be used with a variety of laptops, plus there is a USB port so you can charge any kind of phone with a USB cable.

Here's a link to one that can run off AC or DC. "iGo" Laptop Travel Charger - iGo Green® at iGo, Inc.

I've had good luck with them.

[Mark Johnson]

Originally Posted by Weyalan

Given the power losses with converting DC to AC and then the losses with converting it right back to DC again, I have never been a big fan of using an inverter to run a laptop.

My previous laptop would run quite fine from a standard 12V DC cigarette-lighter type outlet using a DC-DC adaper, with adjustable output, so I would just set it to the required voltage (16V, from memory) and off we'd go.

My new laptop, apparently, has some sensor in the power inlet and won't allow me to do this. So at this stage a small (150W) inverter looks like the only solution...

Any alternatives?

I have used DC to DC converters for years, but never used a variable one. (Could be the A is too low)? If your laptop has its input specs on it, or output specs on the AC black box, it tells you what you need, and should work. Most are 18, 19 or 19.5V DC.

Then look online for "Car adapters" that fit the power requirements, (BOTH V and A), and small end plug for your computer. (There are MANY combinations available).

I do the same thing with our flat screen TV... (run directly off of the boat, with a DC to DC booster to 19V)

IF your laptop came with an AC black box that converts to DC, (rather than doing it internally), and you supply that required DC current, I don't see how the computer would know where its current came from.

I have measured, and the current to run these small things on an AC to DC inverter, rather than the above, is about TWICE as much!

Mark

[noelex 77]

Originally Posted by SV Escape Plan

Where is a good place to purchase said DC to DC converter? Specifically looking for 19.2 volts? Linky please.

You need the correct voltage, polarity, type of plug and adequate wattage The best way is to check the converter lists compatibility with your laptop.


I have used this model and it will run at that voltage.
Discount Ritmo Universal 90W Car DC Adaptor for Laptop / Notebook | CrazySales - Compare Prices & Save shopping in Australia

[Weyalan]

The computer is an HP. The problem, as mentioned by another poster with a Dell machine, is that there is a 3rd wire in the jack and, as such, it won't work with a standard plug on a variable voltage DC - DC adapter. It needs that 3rd wire for something. I have worked around the problem for the time being by buying a small inverter, which seems to work just fine, and has a few other potential uses, sufficient to justify it's existence. We are only using the inverter when we are motoring, for now. I shall investigate buying a proper HP 12 car charger.

Thansk for all your posts / comments.

[Music]

Originally Posted by Mark Johnson

I have used DC to DC converters for years, but never used a variable one. (Could be the A is too low)? If your laptop has its input specs on it, or output specs on the AC black box, it tells you what you need, and should work. Most are 18, 19 or 19.5V DC.

Then look online for "Car adapters" that fit the power requirements, (BOTH V and A), and small end plug for your computer. (There are MANY combinations available).

I do the same thing with our flat screen TV... (run directly off of the boat, with a DC to DC booster to 19V)

IF your laptop came with an AC black box that converts to DC, (rather than doing it internally), and you supply that required DC current, I don't see how the computer would know where its current came from.

I have measured, and the current to run these small things on an AC to DC inverter, rather than the above, is about TWICE as much!

Mark

I am talking about dc to dc converters used in equipment designs, not your wall wort type. Look up enclosed Meanwell dc to dc to see an adjustable converter.