Switching battery banks with engine running - Page 5 - 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
 Not a Member? 
  #41  
Old 09-30-2008
Omatako's Avatar
Senior Member
 
Join Date: Sep 2003
Location: Auckland New Zealand
Posts: 2,449
Thanks: 0
Thanked 30 Times in 27 Posts
Rep Power: 12
Omatako will become famous soon enough
Quote:
Originally Posted by hellosailor View Post
Don't know how to tell you, Andre, but both of those switches ARE ROTARY.
I guess in the purest form you are correct, they are both rotary but they are definitely not the same. The implication that SD (I'm sure) and I were discussing is that the lower of the two can be turned a full 360 degrees, starting from anywhere. That is, one can start from ALL and turn it clockwise through OFF to battery 1 or from battery 1 thru OFF to battery 2.

The top one is not the same. It goes from OFF thru 1 to ALL to 2 but then it has to be turned back clockwise to return to OFF. It cannot continue anti-clockwise to OFF again. The implications for your alternator is that it takes a conscious move to turn it off, not an accidental move in the wrong direction.

Quote:
Originally Posted by hellosailor View Post
From the "STOP ENGINES" warning label on your switch, it would appear to be the most dangerous kind--the kind that does not "make before break".
When it is turned from OFF to any other position it is make-before-break. The only place it does not "make" is in the OFF position for obvious reasons . The stop engines label is just a warning not to turn the power off while the engine is running, nothing to do with the direction the switch turns in. The same result will be achieved on either switch but it doesn't make the top one more dangerous.
__________________

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

__________________

"Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying."

Arthur C. Clarke
Reply With Quote Quick reply to this message Share with Facebook
  #42  
Old 09-30-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 11 Times in 11 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
Or, you could just use an echo charger or battery combiner and a Blue Sea Dual Circuit Plus battery switch.
Quote:
Originally Posted by davidpm View Post
Not saying the following is right or OK but what we do is.

Start engine on 1 (starting battery). If engine starts switch to All to change both batteries while motoring to channel.
Turn off engine and switch to 2 (House bank).
Before starting engine switch to 1 (starting battery)

This is old-school keeping one battery for starting and one for house but requires switching from 1 to All while running.

The only dangerous step is to remember to switch the battery after changing on all. If you leave it on all and run your GPS, Lights etc too much you could kill both batteries and not be able to start.

So to protect against this we keep a changed NAPA starting battery under a bunk just in case. It will start the engine we have tested it.
__________________
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 Quick reply to this message Share with Facebook
  #43  
Old 09-30-2008
Senior Member
 
Join Date: Jun 2007
Posts: 2,708
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
SEMIJim will become famous soon enough SEMIJim will become famous soon enough
Quote:
Originally Posted by GBurton View Post
The label says to stop engines before turning off, not turn off engine before switching....
Idly wondering how one might stop an engine w/o turning it off...

All kidding aside: Other than Steve's one scenario (hadn't thought of that one, Steve), I can think of no good reason to switch the switch while the engine's running. So why tempt fate? Secondly: None of them I've seen have a lock-out that prevents you over-traveling from "1" or "2" into "OFF," so, again: Why tempt fate? But they're your alternators. Me: I'm going to play it safe.

Jim
Reply With Quote Quick reply to this message Share with Facebook
  #44  
Old 09-30-2008
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 11 Times in 11 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
SEMIJim-

Most marine diesels aren't going to be affected by shutting off the electricity to them, since they aren't dependent on an electrical ignition system—they're diesels... so to stop them you need to cut off either the air or fuel.

Quote:
Originally Posted by SEMIJim View Post
Idly wondering how one might stop an engine w/o turning it off...

All kidding aside: Other than Steve's one scenario (hadn't thought of that one, Steve), I can think of no good reason to switch the switch while the engine's running. So why tempt fate? Secondly: None of them I've seen have a lock-out that prevents you over-traveling from "1" or "2" into "OFF," so, again: Why tempt fate? But they're your alternators. Me: I'm going to play it safe.

Jim
__________________
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 Quick reply to this message Share with Facebook
  #45  
Old 09-30-2008
Senior Member
 
Join Date: Jun 2007
Posts: 2,708
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
SEMIJim will become famous soon enough SEMIJim will become famous soon enough
Quote:
Originally Posted by sailingdog View Post
SEMIJim-

Most marine diesels aren't going to be affected by shutting off the electricity to them, since they aren't dependent on an electrical ignition system—they're diesels... so to stop them you need to cut off either the air or fuel.
Which is how you "turn them off."

I think you misinterpreted the nature of my musing

Jim
Reply With Quote Quick reply to this message Share with Facebook
  #46  
Old 09-30-2008
Senior Member
 
Join Date: Jun 2007
Posts: 535
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 8
GBurton is on a distinguished road
Ah ...you’re just being obtuse aren’t you

Quote:
Originally Posted by SEMIJim View Post
Idly wondering how one might stop an engine w/o turning it off...

All kidding aside: Other than Steve's one scenario (hadn't thought of that one, Steve), I can think of no good reason to switch the switch while the engine's running. So why tempt fate? Secondly: None of them I've seen have a lock-out that prevents you over-traveling from "1" or "2" into "OFF," so, again: Why tempt fate? But they're your alternators. Me: I'm going to play it safe.

Jim
Reply With Quote Quick reply to this message Share with Facebook
  #47  
Old 09-30-2008
JohnRPollard's Avatar
Moderator
 
Join Date: Mar 2007
Location: Chesapeake
Posts: 5,680
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 10
JohnRPollard is a jewel in the rough JohnRPollard is a jewel in the rough JohnRPollard is a jewel in the rough
Jim, per your question below. Steve mentioned a scenario where you might want to switch the battery selector while motoring. There are others.

In some instances, both batteries may be nearly depleted, so both are needed to crank the engine over. Normally you would want to recharge them both while running the engine for as long as necessary. But there could be circumstances where you cannot or will not run the engine for very long (short hop, low on fuel, overheating condition, etc). In a case like that, it would be better to give one battery the best charge that you could during the time the engine is running, rather than under charging them both. So you'd switch once the engine was running.

I can think of others, but you get the idea...


Quote:
Originally Posted by SEMIJim View Post
Maybe I'm missing something obvious (it wouldn't be the first time), but why would you need to do this? By "this" I mean: Switch battery use while under way under motor?Jim
Quote:
Originally Posted by SteveInMD View Post
I agree for the most part. I can see needing to switch if you totally run down one battery and the other is partially discharged. You may not want to risk combining them with the battery switch prior to cranking the motor. If you did, the one battery with a partial charge would be trying to charge the dead battery and crank the motor at the same time, which is at best very hard on the battery and at worst will leave you with no ability to start the motor.

The practice of using one battery at a time is old school. The modern thinking is that you should use both at the same time. Your batteries will last longer if you discharge them both a little than one a lot. You should either have a dedicated starting battery, or a monitoring system, or know your usage well enough to not get yourself in trouble, or all of the above.
__________________

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

Pacific Seacraft Crealock 31 #62

NEVER CALLS CRUISINGDAD BACK....CAN"T TAKE THE ACCENT
Reply With Quote Quick reply to this message Share with Facebook
  #48  
Old 09-30-2008
davidpm's Avatar
Senior Member
 
Join Date: Oct 2007
Location: Madison
Posts: 3,818
Thanks: 206
Thanked 50 Times in 42 Posts
Rep Power: 8
davidpm is on a distinguished road
Quote:
Originally Posted by sailingdog View Post
Or, you could just use an echo charger or battery combiner and a Blue Sea Dual Circuit Plus battery switch.
Are you saying an install could benefit from both? How.
They look similar in function.
Reply With Quote Quick reply to this message Share with Facebook
  #49  
Old 09-30-2008
harryrezz's Avatar
Charter Captain
 
Join Date: Dec 2003
Location: Buffalo, NY (warm months), Liveaboard in Caribbean (cold months)
Posts: 48
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
harryrezz is on a distinguished road
Wow! Can't resist chiming in on this one ....
Two key points are rattling around here, but are being missed, probably because we all have diffeent boats with different setups.
First - if your boat is set up with more than one battery YOU SHOULD NOT USE THE SAME TYPE OF BATTERY IN BOTH CIRCUITS!!! You should use a "Starting Battery" in one and a "Deep Cycle" battery (or batteries) in the other. They are VERY DIFFERENT. The "starting" type is designed to give out, in simple terms, a big burst of power for a short time - such as is needeed to start the engine. That's why they are rated as having a high number for "Cranking Amps", and a relatively low number for amp. hours. It is NOT designed to be deeply discharged and then recharged over and over. This will cause the plates to deteriorate very quickly and premature failure will result.
The second curcuit should be used as a "house" circuit, and should be used to power everything else on the boat. Here a "Deep Cycle" battery should be used. They are designed in a very different structural way and are designed to give out a smaller flow of power over a long time. Most do not even have a "Cranking Amp" rating, becaus e that's not what they are for - but they have a relatively high amp. hour rating. They "don't mind" being deeply discharged and recharged over and over ... that's what they are built for ... but they do NOT like to have to put out a big burst of power.
It's simple, really - use a "Starting Battery" for starting and a "DeepCycle" battery to power everything else! Hence the multi-position switch. Set the switch to "1", the Starting Battery, and start the engine. Then switch to "Both" while the engine is running to ensure that both are fully charged. (Note - if you have the proper type of batteries set up DO NOT start the engine in with the switch in "All". Doing so will "ask" that Deep Cycle battery to do something it is not designed for.) After you shut down the engine, move the switch to "2" and the Deep Cycle battery(s) will be the only one(s) connected and will power your accessories. When it's time to re-start the engine, move the switch back to "1", and repeat the above.
In this way you will be using each type of battery as it was intended and you will not only gain optimal performance from both battery banks, you will also get MUCH more servicable life from your battery investment.
BTW - for those of you with only one battery, you should be using a "Dual Purpose" type battery. It won't have quite the cranking amperage of a true "starting" battery, but it will do the job perfectly well, and it will tolerate many more discharge/charge cycles before it goes bad than would a "Starting" battery.
"Automotive" batteries are all "Starting" types in their construction and are not intended for use in boats where they will be asked to deliver power over long periods. This is borne out ny noting that if you even leave the dome light on in your car overnight it will kill the battery!
Uh - in case you hadn't noticed, using your electrical system properly - by which I mean: as it was designed to be used - requires moving that fearful switch while the engine is running!!! That's what it was designed to do, and as long as you don't accidentally turn it to "Off" while the engine is running everything will be just fine.
On La Nostra I have a 950 cold cranking amp starting battery to turn over the big 82 HP Perkins. Once fired up I switch to "All". After I shut the engine down (either at the end of the day or when sailing) I switch to "2" and run off the four 6-volt Deep Cycle Golf Cart batteries - two in parallel, then in series to get the 12 volts for the system - and run everything from the approximately 600 Amp Hour house bank.
I've run things like this on all my boats. I typically get 4 or 5 years from a set of batteries. The ONLY time I start on "All" is if for some reason the starting battery won't kick the diesel over - which is extremely rare.
I should also add that I never plug in to shore power - we do not have it available anywhere I sail. Instead I use a KISS wind generator and two 80 watt solar panels and am able to run the fridge, freezer, water pumps, lights, radios, etc. for days on end without starting the engine.
Hope that puts people's minds at ease - and will also save some of you from spending big bucks on the wrong kind of batteries to do the various things on your boats.
__________________
Captain Harry
Life's Short ... Eat Dessert First!
La Nostra - CSY 44
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Located Southern Caribbean
Reply With Quote Quick reply to this message Share with Facebook
  #50  
Old 10-01-2008
camaraderie's Avatar
moderate?
 
Join Date: May 2002
Location: East Coast
Posts: 13,877
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 15
camaraderie is a jewel in the rough camaraderie is a jewel in the rough camaraderie is a jewel in the rough
Harry...lest someone think that ONLY a starting battery can or should be used to start an engine...let me just add that it is QUITE acceptable to use deep cycle batteries to start your engine. They will not deliver the same CCA's as a starting battery...but most marine diesels don't need extreme amperage and verycold weather starts and a decent sized house bank of deep cycle batteries does just fine in this role. Many people with limited ROOM for batteries would be better off configuring TWO deep cycle batteries with a 1/2/Both switch and starting with the switch on BOTH...thus giving more deep discharge amp hours available for house needs.
A 100ah group 31 battery will NOT for example power a fridge AND other house needs for a day since you can only discharge 50amphours safely.
If you use 2 deep cyclce 31 batteries to start and for house needs...you nnow have 100ah's to power house needs AND both batteries will still be at 12.25V when that has been used so you can still start the engine.
__________________
No longer posting. Reach me by PM!
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




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
READ THIS TODAY-It may save you an engine or at least some time and money! Marleetet Gear & Maintenance 6 07-14-2008 05:28 PM
Electrical Problem - Newbie Not Sure Where to Start wolfmt Gear & Maintenance 32 07-14-2008 10:17 AM
Installing a Automatic Battery Selector Switch artbyjody Gear & Maintenance 24 07-08-2008 08:07 PM
My New Catalina 25 42ndstreet General Discussion (sailing related) 23 09-06-2007 01:17 AM
A Little Help from the Sun Don Casey Cruising Articles 0 12-20-2001 08:00 PM


All times are GMT -4. The time now is 12:35 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.