The basics on power while cruising - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Electronics
 Not a Member? 
  #1  
Old 05-01-2010
Junior Member
 
Join Date: Mar 2010
Location: IN
Posts: 29
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
SirRealism is on a distinguished road
The basics on power while cruising

I've begun looking for my first boat, and my knowledge of marine electronics is virtually nil. Probably the best way to start would be from the goal and then ask for help working backward to what I need to be shopping for.

I'm looking at 25-28' boats for Great Lakes cruising. First choice would be an inboard motor, but I'm not ruling out an outboard. When cruising for a week or two, there's a good chance I'll need to work on my laptop for a few hours a day. I'm looking at worst case here. Most likely, if this happens, it'd probably be prudent to head to a marina to stay for a couple days.

So my two questions are about Internet access and power.

1. For Internet access when away from marinas, I'm wondering if my land-based system will work. On land, I tether my laptop to my cell phone and use Sprint's data network. It's not fast, but it's good in a pinch. Is cell phone coverage something I can generally count on near the shores of Lake Michigan? Is it spotty?

2. To power a laptop for a few hours a day, how much will I drain my batteries? And as they drain, how much might I need to run my inboard to recharge that amount?

2a. Same power issues, but with an outboard. I'm assuming that, even with an electric start outboard, it isn't really going to charge marine batteries to any degree. So should I start looking at solar panels? Perhaps my need to use a computer might be the thing that forces the out/inboard issue.

Thanks!

ETA: I just looked at my laptop's power rating. 3.65A at 16.5Vdc.

Last edited by SirRealism; 05-01-2010 at 03:08 PM.
Reply With Quote Share with Facebook
  #2  
Old 05-01-2010
Gary M's Avatar
Senior Member
 
Join Date: May 2006
Location: Sarnia ON
Posts: 658
Thanks: 1
Thanked 2 Times in 2 Posts
Rep Power: 9
Gary M is on a distinguished road
I used to cruise the North Channel in a Niagara 26 with a Honda outboard to charge the batteries. We got by because we used very little power. I would carry a small kerosene hurricane lamp that I hung from the backstay for as an anchor light for instance.

One small advantage to an outboard is you do not need battery power to start it. That being said I definitely prefer a nice dependable diesel inboard. Very much easier on fuel is a major advantage so fewer trips to a fuel dock.

No idea what cell coverage is like on Michigan, I am on the nicer lake immediately to the right.
Reply With Quote Share with Facebook
  #3  
Old 05-01-2010
Junior Member
 
Join Date: Mar 2010
Location: IN
Posts: 29
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
SirRealism is on a distinguished road
Quote:
Originally Posted by Gary M View Post
I used to cruise the North Channel in a Niagara 26 with a Honda outboard to charge the batteries. We got by because we used very little power. I would carry a small kerosene hurricane lamp that I hung from the backstay for as an anchor light for instance.

One small advantage to an outboard is you do not need battery power to start it. That being said I definitely prefer a nice dependable diesel inboard. Very much easier on fuel is a major advantage so fewer trips to a fuel dock.

No idea what cell coverage is like on Michigan, I am on the nicer lake immediately to the right.
Gary, I've heard rumors that there was a quaint little body of water to the east. Is it still there? Actually, a couple folks have been pointing me in your direction. (Recommendations for Lake Michigan cruiser) I live in Indianapolis, so I'll be driving a few hours, regardless. Toledo is ~ 1 hr farther from me than Hammond, IN. I might be making a road trip to Detroit and/or Toledo in the near future to see check out what's available for sale in those areas.

Last edited by SirRealism; 05-01-2010 at 03:18 PM.
Reply With Quote Share with Facebook
  #4  
Old 05-01-2010
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,071
Thanks: 0
Thanked 68 Times in 59 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
A couple of hours a day shouldn't be a big drain on your batteries. Best to get the 12 volt adaptor for your laptop. If only a couple of hours a dasy you could use the laptop on its internal battery and charge it when plugged in even. '
As far as coverage check with your cell provider or other sailors in the area you will be cruising.
An outboard won't do much in the way of battery charging.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #5  
Old 05-04-2010
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
A few hours a day with a 60 Watt laptop is going to take about 5.5 amps at 12 VDC, assuming some conversion losses going with a DC power supply. If using an inverter, it'll be worse. that's 22 amp hours or so.

How big is your house bank. If you have a single Group 31 battery, which is about 130 amp-hours, three-days use without any other electrical loads will bring down your bank to 50% or so.

You really will want have some sort of passive recharging.
__________________
Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Share with Facebook
  #6  
Old 05-05-2010
kwaltersmi's Avatar
Broad Reachin'
 
Join Date: Aug 2006
Location: Grand Rapids, Michigan
Posts: 1,846
Thanks: 1
Thanked 12 Times in 12 Posts
Rep Power: 9
kwaltersmi is on a distinguished road
Cell coverage for the Verizon network is actually pretty good along Lake Michigan's eastern shore. I've found very few voids from Grand Haven to Charlevoix. You'll also find that many of the ports/marinas have WiFi service available, either for free or a fee.
__________________
Catalina 34

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #7  
Old 05-05-2010
Junior Member
 
Join Date: Mar 2010
Location: IN
Posts: 29
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
SirRealism is on a distinguished road
Thanks for the answers. That's a couple more items down on my pre-purchase checklist. I'm getting closer.

Last edited by SirRealism; 05-05-2010 at 05:50 PM.
Reply With Quote Share with Facebook
  #8  
Old 05-05-2010
Banned
 
Join Date: Mar 2006
Location: subject to change
Posts: 1,264
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
eryka is on a distinguished road
We have found the laptop/cellphone option very dependable everywhere we've gone. MUCH more reliable coverage than an air card from the same provider. Verizon had good coverage in Lake Michigan, ATT better in Chesapeake, so you really have to check your provider network.

A laptop with a large bright screen is quite the power-eater, as S'dog points out. I use a netbook with flash memory (smaller screen, and no spinning hard drive both big power savers) for writing and other "slow" computer jobs, or wait till I'm plugged in. Otherwise, we power our lives with 2 65-watt solar panels.
Reply With Quote Share with Facebook
  #9  
Old 05-17-2010
n8kraft's Avatar
Commodore
 
Join Date: Dec 2009
Location: Pier 32 Marina
Posts: 161
Thanks: 3
Thanked 1 Time in 1 Post
Rep Power: 5
n8kraft is on a distinguished road
For the laptop I'd recommend a DC 12V to DC16.5V power converter. It's more efficient than changing from 12VDC to 115VAC then back to 16.5VDC. An example is here on newegg. I bought one and use it on my boat but for 12V to 12V with my netbook that I use as a chartplotter. When plugged in to shore power the adapter does get hot though. for low voltage it's cool running.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
THE Yacht Builder List T37Chef Boat Review and Purchase Forum 26 07-08-2011 05:51 AM
Calculating the Cost of Cruising Paul & Sheryl Shard Cruising Articles 0 04-03-2003 07:00 PM
Calculating the Cost of Cruising Paul & Sheryl Shard Her Sailnet Articles 0 04-03-2003 07:00 PM
Electrical Power on Board Kevin Jeffrey Gear and Maintenance Articles 0 02-11-2003 07:00 PM
Electrical Power on Board Kevin Jeffrey Her Sailnet Articles 0 02-11-2003 07:00 PM


All times are GMT -4. The time now is 04:32 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.