Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 22-08-2010, 21:59   #16
Registered User
 
svcambria's Avatar

Join Date: Jun 2010
Location: Mexico (currently)
Boat: Panda 40 - S/V Cambria
Posts: 573
"I have been told you can run the laptop fine at 12 volts but it wont charge the battery. Thats fine normally on a boats nav station laptop"

That has been my experience. However - some laptops will run off the 12V independent of battery state, and some will try to charge the battery whenever it sees it is low and overwhelm the system - now it wants upwards of 19V - shutting it down. There doesn't seem to be any way to determine how a computer will react until you buy one - it just isn't part of the specs. If the one you got needs the battery charged before it will work on 12V, I found that charging it up with an inverter and then running it off 12V and not letting the battery discharge will work.

Michael
__________________

__________________
svcambria is offline   Reply With Quote
Old 23-08-2010, 04:37   #17
Registered User
 
richardhula's Avatar

Join Date: Nov 2008
Location: UK
Boat: S M Hudson 60' narrowboat
Posts: 347
Send a message via Skype™ to richardhula
Quote:
Originally Posted by svcambria View Post
"I have been told you can run the laptop fine at 12 volts but it wont charge the battery. Thats fine normally on a boats nav station laptop"

That has been my experience. However - some laptops will run off the 12V independent of battery state, and some will try to charge the battery whenever it sees it is low and overwhelm the system - now it wants upwards of 19V - shutting it down. There doesn't seem to be any way to determine how a computer will react until you buy one - it just isn't part of the specs. If the one you got needs the battery charged before it will work on 12V, I found that charging it up with an inverter and then running it off 12V and not letting the battery discharge will work.

Michael
Firstly laptops & netbooks don't have a common DC input voltage requirement. It varies from model to model between 12 to 24 volts. That is why universal DC to DC adapters offer a switchable output voltage to match requirements.

Having said that I have managed to run/charge a Toughbook requiring 15 volts directly from my 12 volt battery system but only with the engine running holding batteries at 14.5 volts.

Bottom line I wouldn't recommend doing that in anything other than emergency - go to Walmart & buy a universal DC to DC adapter with output power exceeding max requirement of laptop & range of connectors to match. e.g. I have 120 watt one on Acer requiring 90 watts max - doesn't get hot, little or no RF interference.
__________________

__________________
Richard

If in doubt RTFM
richardhula is offline   Reply With Quote
Old 23-08-2010, 06:22   #18
Registered User

Join Date: Feb 2008
Posts: 2,064
Images: 1
Most laptops are designed and rated for 15-19.5v on the input. Low voltage on the input = higher amperage draw on the circuit (if it doesn't shut itself down). In the end it will draw the amount of power it needs (watts) but current (amps) load is a wiring and fuse consideration, and might even result in internal component overheating inside the laptop (not good).
__________________
SailFastTri is offline   Reply With Quote
Old 23-08-2010, 09:44   #19
Registered User
 
svcambria's Avatar

Join Date: Jun 2010
Location: Mexico (currently)
Boat: Panda 40 - S/V Cambria
Posts: 573
Quote:
Firstly laptops & netbooks don't have a common DC input voltage requirement. It varies from model to model between 12 to 24 volts...

Bottom line I wouldn't recommend doing that in anything other than emergency
Certainly. Check the AC adapter, it will tell you what the maximum output should be. I have not personally run across a 24 volt system, but that doesn't mean they don't exist ;-) (All Indians walk in single file - at least the one I saw did...)
My analogy would be that running on unregulated 12V is like driving a car with the skinny little spare tire on - it gets you where you need to go but you don't want to push it. I did use 12V direct from the house battery bank to a Toshiba laptop on a seven week 6800 mile trip across the Pacific and did not suffer from any voltage spikes or low voltage conditions but I wouldn't intentionally set out that way. That passage got me to get a Lind DC/DC converter - the high end stuff at $160 - but most laptop vendors carry a car adapter for their models at much less cost.

Michael
__________________
svcambria is offline   Reply With Quote
Old 23-08-2010, 10:27   #20
Registered User
 
richardhula's Avatar

Join Date: Nov 2008
Location: UK
Boat: S M Hudson 60' narrowboat
Posts: 347
Send a message via Skype™ to richardhula
Quote:
Originally Posted by svcambria View Post
Certainly. Check the AC adapter, it will tell you what the maximum output should be. I have not personally run across a 24 volt system, but that doesn't mean they don't exist ;-) (All Indians walk in single file - at least the one I saw did...)
l
Apple Notebooks use (or did) the higher voltages I mentioned - clearly there is no way they could be powered directly from 12 volt battery bank under any circumstances.
__________________
Richard

If in doubt RTFM
richardhula is offline   Reply With Quote
Old 23-08-2010, 11:55   #21
Registered User
 
Patrick_DeepPlaya's Avatar

Join Date: Feb 2008
Location: Seattle, WA
Posts: 262
Check out the Carnetix DC-DC regulators
DC-DC Regulators for CarPC automotive computers
Good FAQ on them at MP3car.com's forum:
FAQ - Power Supplies Explained - MP3Car.com
FAQ - Will xxxxx Power Supply Work with My System? - MP3Car.com
__________________

__________________
http://www.DeepPlaya.com | Twitter: @DeepPlaya
Patrick_DeepPlaya is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
OpenCPN on a Netbook wbickle OpenCPN 51 27-09-2010 16:10
Powering the House Deebow Electrical: Batteries, Generators & Solar 5 31-07-2010 20:55
MaxSea on a Netbook - Help ? sevans0579 Navigation 1 18-05-2010 15:46
Wifi Woes with a Netbook Chrissy Marine Electronics 17 12-05-2010 13:56
Coastal Explorer and MSI Wind netbook RBEmerson Navigation 7 31-01-2009 00:03



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:03.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.