Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 29-01-2012, 12:10   #1
Registered User

Join Date: Nov 2011
Boat: Gle-l 36
Posts: 23
Boat Wiring

hello there! So I am designing a boat to live on, and now on to the electrical. How do i figure out how many batteries I would need in the battery bank? I do plan on using a 3000 watt inverter, mainly for the galley. If anyone has any information about how much power will be needed for a given number of watts and so forth, also if anyone can point me in the direction of a good website that can introduce me to boat wiring, in particular the AC side. I do have some home wiring experience and lots of dc experience
__________________

__________________
jakegator is offline   Reply With Quote
Old 29-01-2012, 12:20   #2
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Re: boat wiring

Firstly

(a) Marina ( ie shore power) living or anchored
(b) what charging sources will you be supporting
(c) What type of power consumers have you,anything heavy duty ( like Air)

As a general rule, at anchor you can have quite low consumption, with the fridge being the worse, as you will not have full instrument, radar, autopilots to worry about. Hence its easy , do a fridge and lights calculation.

Id say 50-80 Ah, and a battery capacity of about 400Ah assuming good access to recharge sources.

Whats the inverter for, its not that its 3000W that worries me, its its duty cycle.
__________________

__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 29-01-2012, 12:35   #3
Marine Service Provider
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,618
Re: boat wiring

Your going to need to do a thorough power analysis. Start by determining all of the 12 volt equipment you plan on having on board, both at anchor and under way. Calculate the maximum daily usage for all of that equipment and then how many amps it will take to use it all on a daily basis, your amp hours. Go heavy on your figures. Next factor in your inverter use and make the same calculations. What appliances will you need to run and how many amps will the inverter draw from the batteries each day? Add at least 20% to the inverter usage for inefficiency. This will take some work but is what you need to do if you want a correct 12 volt power analysis. Once you have determined your daily amp hour usage, double that and add another 20%. The 20% is a cushion and you double that because you never want to discharge your batteries more than 50%. This should tell you how many of what type of battery you will need to have in your house bank. Chuck
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 29-01-2012, 12:51   #4
Registered User

Join Date: Nov 2011
Boat: Gle-l 36
Posts: 23
Re: boat wiring

Goboatingnow- The first few years I will still be in college so I will be at the dock almost entirely, however I will not be using shore power if at all possible (I will make it so I can use it in an emergence). I plan on using a bunch of solar panels and a wind generator, I will probably carry a small honda genny down the road. The fridge is what I have figured to be the most power hungry so far, its a 14CU foot fridge freezer combo from homedepot, that was on my cousins boat for a few years. As far as lighting im still on the fence as far as LCD vs. Halogen and DC vs. AC trying to weigh the cost to efficiency, happy to hear opinions on that as well.
__________________
jakegator is offline   Reply With Quote
Old 29-01-2012, 12:51   #5
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Re: boat wiring

Chuck, firstly , the OP mentioned liveabord, that condition needs to be fleshed out. If shorepower is readily available then that is a factor.

The other things about power budgets, is the "Calculate the maximum daily usage for all of that equipment" , this can be difficult unless you have the actual equipment. ( duty cycles etc) You can make a stab at it.

The other way is simply to look at whats common in boats, typically thats 200-400 Ah battery banks, 50-80 amps alternators and shore chargers in the 30-50 amp range. Add solar and wind if required.

From my point of view, I would look at my recharge options and or shore power availability and frequency. Since these tend to be the dearest and hence the determining factors, then Id look at what was practical. There's no point in arriving at a bank that you cant charge.
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 01-02-2012, 05:20   #6
Registered User

Join Date: Dec 2004
Location: Kingston, Ontario
Boat: Saugeen Witch, Colvin design vessel name: Witchcraft
Posts: 383
Images: 14
Re: Boat Wiring

On the west marine website (the advice section of things) there is an electrical budget sheet that is very useful for figuring out these things.
http://content.westmarine.com/docume...s/Elecbugt.pdf

It will make a person consider carefully the items they have aboard and how much power they draw . Knowing what you use ( or are likely to use) is your best way to figure out how much battery capacity and charge capacity you require.
Witchcraft
__________________
witchcraft is offline   Reply With Quote
Old 01-02-2012, 05:36   #7
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: Boat Wiring

Jakegator,

No matter which hoops you jump through, for a liveaboard there's no way you can generate your own power for less $$$ than the cost of shorepower.

Even if your boat is already fully equipped (batteries, inverter, solar panels, generator, etc.) if you figure the REAL costs I think you'll find it much less expensive and better to plug in.

Nigel Calder has done some interesting calculations in this regard. Power generation onboard isn't cheap and is always more expensive than you first think.

Bill
__________________
btrayfors is offline   Reply With Quote
Old 01-02-2012, 06:19   #8
Registered User
 
Randal Johnson's Avatar

Join Date: Feb 2008
Location: December 2014 Back in Marmaris Turkey getting Dora Mac ready to put back on the market.
Boat: Diesel Duck 462 M/V Dora Mac
Posts: 114
Re: Boat Wiring

Here is a down loadable book from Victron on boat electrical design.
http://www.rpc.com.au/pdf/Victron_Energy_Unlimited.pdf
__________________

__________________
Randal Johnson is offline   Reply With Quote
Reply

Tags
wiring

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
Girl Overboard ! TigerLilly Health, Safety & Related Gear 82 24-02-2016 23:07
Woman Living on a Boat ? freya34 Liveaboard's Forum 66 24-07-2012 17:21
Boat Reviews sailorboy1 Dollars & Cents 31 14-12-2011 17:20
Safe Boat Operations New Boat Handling and Maneuvering Skills Mariners Commercial Posts 0 05-10-2011 14:07



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 19:41.


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.