House vs starter bank charging

[WindyT]

When connected to shore power, how do folks leave there battery selector switch while charging? 
For example, many people on this forum have the following:  house bank of 4 6V batteries in series/parallel and the reserve / starter bank is a deep cycle 12v of some form.  Does leaving the switch on 'all' affect battery life?  I'm even seeing fairly commonly house bank flooded lead acid batteries paired with maintenance free AGM reserve bank.  My impression was that leaving the switch on all would negatively impact the life of all of the above but I am certainly a novice.

My current setup is 4 150Ah AGM batteries (2 on bank 1 and 2 on bank 2).  Planning to revert to normality with the golf cart + reserve bank but curious how to make these expensive little puppies last!

Please enlighten me.

WindyT

[frankya]

One of the first things you need to decide is what function you really intend  for them to do .
There will be a difference in management decisions between a "Starter" battery and a "Reserve" battery.

I, for example, have 2 4D's, paralleled, as the "Normal" bank. Used for everything.Then, I have a group 27, designated as a "Reserve" Bank.
This doesn't get used - only monitored for health - and is for if and when the "Normal bank fails to perform. I cant see ANY circumstance where my battery switch would be on  BOTH.

The charger on my boat is not wired thru the battery switch - the charge sources go directly to the batteries - connection to the charger is not dependent on the 1-B-2 switch at all. And in fact, I have a on-battery disconnect switch on the Reserve battery, if I want to take it out of the charging circuits.  I manage "one" bank- the "normal" one - and occasionally check the health of the "reserve" bank.

There are almost limitless options, and there is a trove of info on this site - have you checked out the "Electrical Systems 101" yet?

[scgunner]

    Annie,

      Frankya is correct, your options are limitless, you'll have to decide what's best for you. I have three Group 27 batteries on my house side and one Group 24 on the start side, when I'm on shore power I leave the Battery Selector Switch on "All" and have since '88 when I got the boat, it seems to work fine that way and I've noticed no ill effects.

[Stu Jackson]

You should consider wandering over to

Electrical Systems 101   http://c34.org/bbs/index.php/topic,5977.0.html

These links from that topic explain how things work and how & why:

OEM 1-2-B Switch Wiring History  http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101

Basic Battery Wiring Diagrams  This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring:   The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

This is a newer primer for boat system wiring design with a thorough digram:   Building a Good Foundation (October 2016)
http://forums.sailboatowners.com/index.php?threads/building-the-dc-electrical-foundation.181929/#post-1332240

The Short Version of the 1-2-B Switch Stuff:  http://c34.org/bbs/index.php/topic,5977.msg38552.html#msg38552  This is a link to the Electrical Systems 101 Topic, reply #2

What are ACRs, Combiners & Echo Chargers?  (by Maine Sail) [scroll to the top]
http://forums.catalina.sailboatowners.com/showthread.php?p=742417 and http://c34.org/bbs/index.php/topic,9404.msg70131.html#msg70131

Making Sense of Automatic Charging Relays  (2019)
https://marinehowto.com/automatic-charging-relays/


Any more specific questions we'd be pleased to respond to.

[WindyT]

Thanks all!

Stu - I've actually been spending a lot of time there and planning to do a lot of rewiring. John's DIY posts are especially awesome!  What a great resource.

Since the PO made bank 1 and bank 2 essentially the same (both are 2 12v glass mat batteries in parallel), I've keep the switch to Both while charging (even though charger wired to bank 1).  He recommended to keep it to Both all the time when I bought the boat.  ...something I didn't question until recently. 
The one thing I couldn't find was curious about the ill effects of using charger to top of the reserve bank if it's a different type or capacity of battery.

Thanks again!

WindyT

[mark_53]

When connected to shore power, how do folks leave there battery selector switch while charging?

I have rewired 2 grp 27 batteries to function as a house bank and 1 grp 24 as a start/reserve bank.  Both are FLA batteries.  I turn my charger off when connected to shore power unless I'm charging the batteries.  If charging I leave 1-2-B on battery #1 (house).   The ACR takes care of the start battery charging.

For example, many people on this forum have the following:  house bank of 4 6V batteries in series/parallel and the reserve / starter bank is a deep cycle 12v of some form.  Does leaving the switch on 'all' affect battery life?

Probably, but it depends on what loads left on.  Safer to turn if to off when when leaving, then you know all is off,  You still may have leach loads that are connected directly to the house bank like the bilge pump or FM radio.

Planning to revert to normality with the golf cart + reserve bank but curious how to make these expensive little puppies last!

Turn everything off when leaving the boat (unless you absolutely have to have cold beer).  Make sure they don't go below 50% SOC.  Get a decent volt meter and measure your SOC.

[Stu Jackson]

To reinforce the concept of the Electrical Systems 101 topic:

IT ALL DEPENDS ON HOW IT'S WIRED

[/font]

It simply DOES NOT MATTER WHAT OTHER SKIPPERS DO unless they tell you how their boat is wired.

[Stu Jackson]

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The one thing I couldn't find was curious about the ill effects of using charger to top of the reserve bank if it's a different type or capacity of battery.

WindyT,

This is another "it all depends" issue.  FLA (wet cell) and AGMs have remarkably similar voltage requirements for charging, while gels and wet cells do NOT. 

I have in the past suggested downloading any alternator regulator manual from www.balmar.net.  Every single one of their installation manuals has a very good table of charging voltages for various battery chemistries.

And capacity has nothing to do with it, because with the proper maximum voltage battery acceptance determines how much current goes to each bank.

You might want to do a Google search on Yandina Combiners.  Their website explains how this works for almost any VSR.

The Ample Power Primer also discusses this.

Unless you mix two completely different types of batteries it should not be an issue.

[Ron Hill]

WindyT : Regardless of your "battery setup"; why would you stay plugged into shore power if you are not running anything off the 12V system (with the battery selector on 1/2/All) ??

A thought 

[scgunner]

     Ron,

       Probably because batteries won't store power indefinitely. If that were the case you wouldn't need a shore power source at all, you could just charge the batteries when you ran your motor. As for me I like a cold beer or a cocktail occasionally when go down to the boat so I leave my reefer on, necessitating a shore power hookup.

[Noah]

Kevin—me too on staying plugged in and charging; with the reefer running on 12v. a 12v fan in aft cabin and a 110v dehumidifier in main salon—all running. But I learned to "not go there" on our Forum! It is like talking religion, polictics, or anchoring preferences!  There are the WHAT?!!?  "you are crazy/lazy, walking a disaster tightrope..." and "buy a bag of ice from the 7/11 store" believers—and me/us. I have good/new electrical on my boat and dock, and I have factored in replacing my original Cold Machine 100 reefer when it finally dies... at some point. so far so good!

[scgunner]

     Noah,

       I definitely know what you mean, we all live in different parts of the country and sometimes what works in one place doesn't work in another. I just go with what works for me. While I have no hard evidence to prove it one way or the other my feeling is that having your reefer on constantly(like your household unit)is beneficial to the units longevity as opposed to having it switched on and off for periods of time. I just replaced my Cold Machine last year after 31yrs of constant operation and what caused it's demise was the refrigerant lines corroding through and not a unit failure.

        And if you think refrigeration is a touchy subject try the flash water heater topic. I have been told on more than one occasion that I'm going to burn down my boat, but guess what, I like having a lot of hot water on demand. I installed my flash heater about 20 years ago and it's been reliably providing hot water ever since. Works for me.

[Stu Jackson]

As one of those "buy a bag of ice from the 7/11 store" believers'" I must admit that Kevin and Noah are right. 

Different strokes for different folks. 

Having moved, in a major way, from benign SF to "winter's are chilly here in BC," I now leave my boat plugged in all winter with the heater on medium so I can at least spend more time in the boat during the rare sunny winter days.  The battery charger's always on now, too, which I never had to do because when I lived in SF I could use the boat all winter every few weeks, and I check the battery water level much more often.  It didn't snow and then rain inside the boat without heat!  And my drinks stay cold during the winter so I don't have to run the fridge all the time! 

Moving taught me a lot.  Weather does matter.

[Ron Hill]

Kevin : I understand leaving the boat with the fridge ON and then there is a need for shore power charging.  However if nothing from the 12V system is ON - I always left the boat with the battery selector OFF and the shore power disconnected.

I see that WindyT has AGMs which do NOT self discharge like flooded batteries. I don't leave the boat for more than a week and then plug back in while I'm onboard doing things.

Guess when our marina had a power line hit by lightening and the plugged in boats were fried, I seldom leave the boat plugged in!! 
As Stu says, Your boat your choice.  A thought

[Bobg]

about ten years ago a taller boat 3 slips from me got hit by lightning and it took out my on board charger, didn't affect the two boats between us that weren't plugged in, I tend to unplug the boat when i leave now. not always, but I do think back to that day.  everyone on my dock chastise me for it but I'm the only mast on my dock, rest are power boaters, they may be thanking me one day, lots of lightning up here in lake superior