Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 13-02-2018, 20:11   #31
Registered User

Join Date: Feb 2015
Location: Oakland CA
Boat: Morgan 46 ketch
Posts: 453
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by valhalla360 View Post
500amp-hr of lead-acid batteries is only about 3kwh of usable power if you start out fully topped up. Less if you only got back up to 80% full the day before.

Generators are really best to handle big loads like air/con. They are pretty limited for battery charging as once you hit 80-90% charge, the charge acceptance by the batteries drops off quickly.

If you aren't running the air/con or similar, solar can keep up nicely with that battery bank and reasonable loads.
Lot of too general statements there. How much solar? What are reasonable loads? If you want ice cubes in the tropics with only solar charge source, finding or making room for sufficient panel area is really difficult on a monohull.

For many, the generator is indispensable for the big loads required for bulk charging up to about 90% of AH replacement. Then a modest solar array is good for the longer, low current absorption process of completing full charge.

To enable the full charge which is recommended often for AGM batteries, using the solar panels, you can pick a sunny day and minimize or eliminate high current loads during that period. BTW, Good reason for holding plate reefers.
__________________

waterman46 is offline   Reply With Quote
Old 14-02-2018, 00:17   #32
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Boat: Bestevaer.
Posts: 10,951
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by kmacdonald View Post
Don't 12V battery banks over 500 Ah become less attractive than a generator? The weight and complexity of charging large banks and the ability of a generator to run AC seems to favor generators instead of large battery banks.
I think you are mixing up a source of power generation and a means of storing the power. These are really two quite different things. The largest battery bank in the world still does not make any electricity. Ironically, boats that rely on a generator for the majority of their power generation often require a battery bank that is larger than boats generating most of their power from alternatives such as solar, wind and hydro.

The first thing to get right is how you are going to replace the power that is used. There is no perfect solution, but it is important to choose the option that is best for you. Based on this primary decision, the ideal bank size can then be selected, although other factors need to be taken into account.


Quote:
Originally Posted by Pizzazz View Post
In my setup, I burn one gallon of diesel making at least 350 Ahrs which is enough to make 125 gallons of water. If the engine is used for propulsion as well, the efficiency is double that. It also heats the water for free. It is hard to beat that with solar, even if you factor in an engine replacement cost every 10 years or so (I did replace the original engine a year ago, after 34 years).
People often do a detailed cost analysis of various power generation options, but in most cases cost is a minor consideration. There are other far more important factors. With a 31 foot boat and requirement for 350AHrs, there is no choice but to use a generator.

Sources of alternative power such as solar would generate far less AHrs on your boat. Living with less electricity is less convenient, on the other hand this solution is more reliable, with no noise, smell or heat. The two approaches are very different and will affect your cruising lifestyle in a fundamental way.
__________________

noelex 77 is online now   Reply With Quote
Old 14-02-2018, 03:44   #33
Registered User

Join Date: Aug 2015
Location: Marina del Rey
Boat: Hunter 31
Posts: 589
Re: Feasibility of Large Battery Banks

@nolex77 I totally agree that generation and storage are different activities but they are related. Generation must equal consumption over a period of time. Storage determines that period of time. For some it is at least eight hours to allow for uninterrupted sleep. Others like a daily schedule, especially if using solar as the Earth rotates once a day. Others prefer a weekly schedule for some reason.

The bottom line is that if you are using a generator it makes little difference if you run it twice a day for an hour, once a day for two hours or once every other day for four hours.

For the record, I do not consume 350 AHrs/day, may be a third of that. The point was that if one gallon of diesel gives you as much, the business case for solar and larger batteries is negative.
Pizzazz is offline   Reply With Quote
Old 14-02-2018, 05:35   #34
Don't ask if you can't handle it
 
sailorboy1's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: On the boat somewhere
Boat: Hunter 410
Posts: 13,220
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by Pizzazz View Post

The bottom line is that if you are using a generator it makes little difference if you run it twice a day for an hour, once a day for two hours or once every other day for four hours.
Once you live and cruise full time on your boat you will find it makes a LOT of difference.
__________________
jobless, houseless, clueless, living on a boat and cruising around somewhere
sailorboy1 is offline   Reply With Quote
Old 14-02-2018, 05:58   #35
Registered User

Join Date: Jan 2017
Posts: 5,588
Re: Feasibility of Large Battery Banks

To me the whole premise of the question is nonsensical.

One produces electricity, the other stores it.

If you have the ability to easily charge your bank at will by running a genny, that reduces the size of the bank you need.

A bigger bank lets you go longer between charge cycles.

Other than that, it's a question of the situation and preferences, balancing the various factors.

Lowering consumption, increasing solar, size of the boat, how long away from shore power, whether you care about looks, putting up with noise, etc

There is no one rule fits all, your money your boat

LFP helps with a lot of lead's downsides
john61ct is offline   Reply With Quote
Old 14-02-2018, 06:24   #36
Registered User

Join Date: Jul 2012
Posts: 43
Feasibility of Large Battery Banks

Big. Battery bank, no question. 34 Tollycraft sedan. Twin Cummins 5.9. For ease of maintenance and overall simplicity I removed my 5k Northern lights. The engine room grew much larger and ease of maintenance much improved. (No longer do I have to hire that gangly 14 year old to change the out board oil filter - or clean up the mess.) I installed 8 DYNO D-145 + the nice DYNO boxes http://www.dynobattery.com/ in the lazarette (approx $1K) giving 960 a/h added benefit...these HD units can be drawn down to 30% w/o compromising lifespan. 3 days on the hook easy w/o additional help from solar or spinning the alternators. Still have to be reasonable, can't run every gadget at once, but I can't do that on shore power either. Running HD Balmar alternators with. magnum 2000 inverter. In another life I had 3 $uper fancy gels $700 ea. 200 a/h ea. loved the small footprint but forgot to see if they were delicate and fussy. Only ran them below 50% a couple of times. I got 2 years...and a lecture. A dock neighbor replaced his DYNO setup after 12 years. They were still going strong, but he just wanted something to do. HEY....Happy Valentine's Day!
CascadeThumper is offline   Reply With Quote
Old 14-02-2018, 06:44   #37
Registered User

Join Date: Jun 2010
Location: Easton, MD
Boat: Catalina 22 Capri, 15' Catboat, Bristol 35.5
Posts: 1,503
Re: Feasibility of Large Battery Banks

Are we seeing people trying to justify massive energy storage and generation decisions they have made for themselves or just a comprehension issue. Now if cost is a "minor consideration" you can over design to the hilt. Unfortunately those with limited resources need to be a little more objective.
kmacdonald is offline   Reply With Quote
Old 14-02-2018, 07:52   #38
Registered User

Join Date: Jul 2012
Posts: 43
Feasibility of Large Battery Banks

Some seem to almost take offense at those of us running big battery storage. But here in the PNW the weatherman is not reliable. It is kinda peaceful to hang out in a little cove without diesel clatter and fumes while waiting for the weather to clear. Chances are you might have other boats beside you or even rafted. Don't put the generator exhaust close to your rafted neighbors shiney fiberglass. Lots of beautiful State Parks with little docks or mooring bouys. Same situation. I want to be polite to my neighbors and When I had one, I wanted to run the generator at the same time they were settling with drinks or dinner. In addition, we have some fabulous areas (Princess Louisa Inlet - Chatterbox Falls." One day is not enough to revel in the beauty. Shore power is definitely out of the question. The small dock is posted with "Generators only 11 to 3" of course that is prime time for hiking or dingy cruising. Everyone is very nice until the 11to 3 rule is broken the sea change is dramatic. Biggest offenders are the bigger yachts that come in in the afternoon and anchor out because the would not fit at the dock anyway. It's cocktail hour no need to run in with their dingy. When they run their generator in the evening, or longer, their morning dockside reception is beyond rude. Sure there are multiple arguments but I don't even want to go there. Im happy with my big batteries. I'm happy just to keep a low profile and have fun. No need to rock the boat, that will take care of itself.
CascadeThumper is offline   Reply With Quote
Old 14-02-2018, 10:41   #39
Registered User

Join Date: Jan 2017
Posts: 5,588
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by noelex 77 View Post
With a 31 foot boat and requirement for 350AHrs, there is no choice but to use a generator.
If motoring often enough, a quality HO alt setup could eliminate a dedicated genny.

Or getting onto shore power overnight could do the same.

As discussed above, a bigger bank just increases the time interval between charge cycles.
john61ct is offline   Reply With Quote
Old 14-02-2018, 10:53   #40
Registered User

Join Date: Jan 2017
Posts: 5,588
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by kmacdonald View Post
Are we seeing people trying to justify massive energy storage and generation decisions they have made for themselves or just a comprehension issue. Now if cost is a "minor consideration" you can over design to the hilt. Unfortunately those with limited resources need to be a little more objective.
A 500AH bank is not massive, I know plenty of land-based camping setups with more, some with less than 10' long living space.

None with limited resources would even think about air conditioning away from shore power, that is truly "massive" on the consumption side, by itself dictates you use a genny.

Cost are dictated from your needs, and up-front needs to be distinguished from ongoing over time.

No one can advise you more specifically than what's already been laid out above in this thread, unless you get more specific about your situation, AH per day energy requirements guesstimate, sailing / usage patterns, preferences, boat details etc.
john61ct is offline   Reply With Quote
Old 14-02-2018, 12:02   #41
Marine Service Provider

Join Date: May 2011
Location: PDX
Boat: Gulfstar 50
Posts: 1,122
Re: Feasibility of Large Battery Banks

Some do take offense at any decision trade offs that you might have made. I am often amused when "those" people tell me (or you) how we just made a wrong decision because it is not optimal or cost effective, etc. Really, I have no idea if they just have a need to justify their choices (yours are after all a threat to their way of looking at the world) or what.

Be that as it may.

So many of our "views" on battery sizing is based on limits of some sort. Cost, size, weight, ability to charge, time to charge to name a few.

LiFePO4 is reducing the some of these. Less size, less weight, higher charge density, greater acceptance rate.

Usage patterns are predicated on the solution to these limits.

Let's say for a moment that we can buy di-lithium based batteries. These batteries (for sake of argument) weigh 600 pounds, cost $450 and can store 4 MWh (4000 kWh). They can be left at 100% charge or 0% charge for months with limited problems. Mostly the problems show at near 0% charge.

They can be charged at a 1 MWh / minute rate but are happy at a much lower rate.

How would you use them?

With that much power you could run an electric motor to your prop. Likely you could get 75 to 100 hours run time before depleting the battery.

You might at the start of the cruising season head over to the commercial charging station and "top" off your batteries at the beginning of the season.

As you cruise you just use power as you need to. The charge level drops and you replace some of it with Solar. By the way did I say that your entire boat is a solar panel? With solar giving about 1 KW per sq meter max you end up with oh say an average of 8 KW from the surface of your boat at max sun.

So the charge level of your bank drops down as you use it and rises up a bit in sunlight. The level of charge just floats up and down for weeks.

Perhaps you start getting down to the lower end of the charge level so you find a marina with a charge station and top it off again.

Fantasy of course (at least for today). But how about tomorrow?

Right now I have 100 gal of diesel on my boat. This is about 4 MWh of power. So in some ways we have been doing exactly what I've described. Storing up to 4 MWh of power, using it as needed, topping it off etc.

How about hydrogen fuel cells coupled with a way of making H2 from seawater....

There is a long haul truck company that is planning on using hydrogen fuel cells to power its tractors. They are expecting a 300 to 900 mileage range based on the amount of hydrogen tankage you order. No batteries to speak of, no diesel, electric the whole way.

Not so far in the future. I like big batteries.
evm1024 is offline   Reply With Quote
Old 14-02-2018, 14:34   #42
Senior Cruiser
 
StuM's Avatar

Cruisers Forum Supporter

Join Date: Nov 2013
Location: Port Moresby,Papua New Guinea
Boat: FP Belize Maestro 43
Posts: 7,574
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by noelex 77 View Post
Ironically, boats that rely on a generator for the majority of their power generation often require a battery bank that is larger than boats generating most of their power from alternatives such as solar, wind and hydro.
That is very true! With a steady stream of energy input from solar/wind/hydro to both power your needs and to top up your storage, you don't need nearly as much storage as you do if you only replenish over a short time period and then need to draw on that stored energy for everything.
StuM is offline   Reply With Quote
Old 14-02-2018, 18:50   #43
Registered User

Join Date: Mar 2017
Location: Richmond, VA
Boat: Carver 356
Posts: 134
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by Evenstar View Post
It's really inefficient to run even a dinky 1Kw Honda noisemaker to service even 15A (180W) worth of house lights and refrigeration. Better to run the goddamnednoisybox to charge up your batteries in a couple of hours then enjoy the quiet.
Uh, I think you need to replace the batteries in your calculator.

Amps x voltage = watts.....15 amps x 110 volts = 1650 watts and you would need a Honda 2000 to run that and 1650 watts, I think is the max continuous output of a Honda 2000. A Honda 1000 won't even come close.
Chuck34 is offline   Reply With Quote
Old 14-02-2018, 18:57   #44
Registered User

Join Date: Aug 2015
Location: Marina del Rey
Boat: Hunter 31
Posts: 589
Re: Feasibility of Large Battery Banks

Yom good for the lp you H
AVERAGE
Ok I nu
Pizzazz is offline   Reply With Quote
Old 14-02-2018, 19:11   #45
Moderator
 
Paul Elliott's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Posts: 4,363
Images: 4
Re: Feasibility of Large Battery Banks

Quote:
Originally Posted by Chuck34 View Post
Uh, I think you need to replace the batteries in your calculator.

Amps x voltage = watts.....15 amps x 110 volts = 1650 watts and you would need a Honda 2000 to run that and 1650 watts, I think is the max continuous output of a Honda 2000. A Honda 1000 won't even come close.
I think Evenstar was talking about 15A from a 12V house battery. 12V x 15A = 180W.
__________________

__________________
Paul Elliott, S/V VALIS - Pacific Seacraft 44 #16 - Friday Harbor, WA
www.sailvalis.com
Paul Elliott is online now   Reply With Quote
Reply

Tags
battery

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
feasibility of variable length hull/variable beam cat... black_sails Multihull Sailboats 15 04-05-2016 08:11
Feasibility of an Atlantic Circuit on a very short Sabbatical? Dockhead Atlantic & the Caribbean 29 03-12-2012 16:54
Question About Feasibility Star Journey Monohull Sailboats 0 12-07-2010 14:57
Battery Bank. two banks or one rsn48 Electrical: Batteries, Generators & Solar 16 07-06-2007 17:17



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:18.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.