Is using a lap-top going to use too many amps

[ty.gregory]

I have heard that a lap-top computer eats up a lot of Amps. I use my computer for writing, not surfing the internet. Is this going to be a problem on the hook? I fully expect to have a catamaran with solar and wind-gen. I probably will use the lap-top four, five, six hours a day. I plan to be in the Caribbean, Bahamas, and other warm climes and hope to have a water-maker, a fridge/freezer, and autopilot. What say you????

[EveningTide]

My laptop draws 4 amps when running but very little when in sleep mode. I have a 55 watt solar panel and a 20 watt panel that together generate 6 amps when in direct sunlight and my boat batteries do not discharge if the panels have sun. If I use the laptop at night I must allow time for recharge. I am careful to use sleep mode whenever I take a break from computing and this probably helps. I don't use much other electricity when at anchor so this setup works quite well for me.

[Richard_W]

I wonder if working from laptop's battery and recharging when needed would not be more Ah efficient than having the brick connected all the time?

[Lake-Effect]

Originally Posted by ty.gregory

I have heard that a lap-top computer eats up a lot of Amps. I use my computer for writing, not surfing the internet. Is this going to be a problem on the hook? I fully expect to have a catamaran with solar and wind-gen. I probably will use the lap-top four, five, six hours a day. I plan to be in the Caribbean, Bahamas, and other warm climes and hope to have a water-maker, a fridge/freezer, and autopilot. What say you????

It's simply an arithmetic problem.

You find out how much current your desired laptop draws directly from 12v, or how much current your inverter chows down on if you're running/charging the laptop using an AC power supply... multiply by the number of hours you expect to be working and/or charging, and add that consumption (amp-hours) to your 12v energy budget... and decide whether it's doable or not with your current battery banks.

There are some more energy-efficient ways to approach the issue:
- select the most efficient laptop or netbook that will do what you want
- build a custom 12-powered PC using the most efficient components you can get away with.

I've gone the netbook route - the smallest most efficient netbook that will still support what I want to do.

[noelex 77]

Typical 15 inch laptop 3.5A
Typical netbook 1.3A
iPad 0.5A

The above figures are for a DC to DC converter. Using an inverter will add another 30%.

Note the figures are averages. If you need lots of processing power the ULV laptops are another option they seem to about 2.0 -2.5 A, but I have not measured many of them.

I have just ordered a custom fan less computer. It will be interesting to see how much it draws.

Other than using. DC to DC converter other power saving tips are
Keep the screen brightness down
Use the maximum battery life option (slows the processor)
SSD help
A low resource operating system like Linux (although this depends on how well it controls the chips power saving functions)
Turn off wifi, Bluetooth when not used

[ty.gregory]

Thank you, all. My problem is that I have no idea what it is like to type on an "netbook" or an iPad. Richard W., I was wondering the same thing. I was thinking if
having two batery bricks, one charging while I use the other.

By the way, are there computer screens nowadays that, like a Kindle, allow you to read the screen in sunlight?

[Paul Elliott]

I usually use a netbook at the navstation, and for real keyboard work I use a wireless trackball and keyboard (the trackball is much better when you're under way and the chart table area is small). The netbook draws under 2A @ 12V.

[roverhi]

I use the Apple Blue Tooth keyboard that came with my iMac with the iPad. Typing on the iPads screen keyboard drove me crazy. Probably can use any Blue Tooth keyboard with an iPad though would want to check that before I committed. Just have to go into System Preferences and enable Blue Tooth to get the Apple keyboard to work. If you are going to travel without the Blue Tooth Keyboard be sure to turn off Blue Tooth as the onscreen keyboard is disabled while it's on.

Did a TransPac with a Netbook and didn't notice any excess current draw. Probably had it on 4 hours a day sending email and writing. Have 260 watts of solar but heavy overcast for the first 10 days. No refrigeration but ran the chart plotter, AIS 24/7, LED Nav and interior lights after dark, and HF radio for a couple hours a day contacting the MM net and sending email.

[GrowleyMonster]

I Di aall mu typjng on A TAblet. These days a d it wirks greT for me.

[Sumner]

I built a 12 volt computer...

Computer-Chart Plotter-Navigation Index

...a couple years ago that is very efficient and will soon build another with a faster chip set, but about the same power demands.

We also now have two Gateway netbooks from Walmart ($228) that don't use much as backup to the ships computer and when we use Ruth's laptop we use a DC to DC converter that is more efficient than a 110 inverter going to the laptop's standard brick. The netbooks have 320 gig drives and work with a GPS puck and connect to a chartploter using OpenCPN with a $12 serial/usb cable.

For the use you have envisioned I'd consider a true 12 volt computer like I and others have made or that you can buy from people like Island Time PC...

Marine PC's & WiFi by IslandTime PC

Here is the board I'll use in the new one and it has its own 12 volt power supply build into the board that saves about $70 over the one I had to buy for the present computer...

Intel DN2800MT Intel Atom N2800 Mini-ITX Motherboard | Cedarview

The thing I like about these computers over a tablet for my use are a full size keyboard, mouse, 320 gig or larger hard drive ( I currently have 140 gigs on the drive with all of our web site and all development software), a DVD drive, many USB ports and a number of RS-232 ports that are used with OpenCPN and SeaClear for our navigation along with a 16 inch monitor. All of that using less than 2 amps (12 volt monitor included) and also long distance WiFi (using slightly more),

Sum

[Richard_W]

Originally Posted by ty.gregory

Thank you, all. My problem is that I have no idea what it is like to type on an "netbook" or an iPad. Richard W., I was wondering the same thing. I was thinking if having two batery bricks, one charging while I use the other.

By the way, are there computer screens nowadays that, like a Kindle, allow you to read the screen in sunlight?

Netbook is a bare bones low-power laptop with functional keyboard. It's not like a tablet with the on-screen keyboard.

Most laptops these days come with shiny glossy hi-res screens that dazzle when playing HD video ... and like an iPad are not good at all in full sun.

One would hope that some of the new models of netbooks would come with screens similar to those in Kindle ... they are called e-ink screens ... but I have not noticed. Might be worth searching the net.

[skipmac]

If I have to do a lot of typing I prefer a computer with a full sized keyboard or an external full size. The netbooks I'm thinking about have a slightly smaller keyboard and I just can't type as fast.

The 12V customer built is a nice option if you have the time and know how but you can probably buy a good netbook for less money.

[Sumner]

Originally Posted by skipmac

If I have to do a lot of typing I prefer a computer with a full sized keyboard or an external full size. The netbooks I'm thinking about have a slightly smaller keyboard and I just can't type as fast.

The 12V customer built is a nice option if you have the time and know how but you can probably buy a good netbook for less money.

I touch type and am getting my fingers up to speed on the netbooks we use on the road, but still type faster on the full size keyboard and way faster than on a tablet.

I really like the netbook, but it isn't as versatile as our dedicated 12 volt computer, but for most it would work fine. The dedicated 12 volt is more expense, but still for someone using it 4-6 hours a day or even less well worth it in my opinion.

I don't notice the speed being a problem with either option for internet, word processing and web development with some photo editing for our web site, but they aren't as fast as some people might want if trying to do cad type work or gaming,

Sum

[Wanderlust]

I don't know if all or most laptops have settings where you can change the power settings, but my low range Lenovo on Windows 7 does. I have set the CPU usage and brightness down when running on battery so it consumes less power.

I also swapped out the hard disk and replaced it with a solid state drive which is faster and uses a little less energy. The faster drive also offsets the reduced CPU setting somewhat.

With simple tasks like your word processing you could easily wind the CPU usage to say 50%. When you connect to power, it would instantly revert to full power capability.

You can also turn off bluetooth, wifi and other power consuming functions.

These all mean less drain on the boat batteries.

[Lake-Effect]

Originally Posted by ty.gregory

Thank you, all. My problem is that I have no idea what it is like to type on an "netbook" or an iPad.
...
By the way, are there computer screens nowadays that, like a Kindle, allow you to read the screen in sunlight?

Most netbooks have 2 or 3 USB ports, so you can always plug in a full-size keyboard and a mouse, if typing comfort is paramount.

I'm told that decent sunlight-readable displays exist, but the only ones I've actually seen in person are on Panasonic Toughbooks ($$$$)

Originally Posted by GrowleyMonster

I Di aall mu typjng on A TAblet. These days a d it wirks greT for me.

[coffee spit-take]