Dumb question- battery switches...

Discussion in 'General Discussion' started by Black Valkyrie, Jan 28, 2018.

  1. Black Valkyrie

    Black Valkyrie Member

    411
    Jul 19, 2014
    Canada
    1993 Sundancer 270 DA
    Twin 4.3
    Can someone please help explain my battery switches to me? 1993 Sundancer 270DA, twins. I have a house battery and a starter battery. I can never figure out the switches...

    Main switch is off, 1 , 2 or "all". 2nd switch is on or off.

    I know the 2nd switch has to be on for the 2nd engine to run.

    I assume that the main switch - "all" must be all the batteries?

    Anyways- any help appreciated. Know this is probably a "dumb" question. Also once the question is answered how do I confirm it is actually so on my boat?

    Thx
     
    Last edited: Jan 28, 2018
  2. northshore

    northshore Well-Known Member SILVER Sponsor

    Jan 17, 2011
    Cleveland, OH
    1989 340 Sundancer
    Raymarine E90W Radar/Chartplotter
    Twin 454 Mercruiser 340's
    'All' just means 'parallel batteries 1 and 2'. - IF ITS WIRED RIGHT.

    Mine are not. I have a single battery port and two starboard.
    I have the same switch layout. My starboard switch is wired in a manner that does not utilize the two starboard batteries as independent. They are wired in parallel right at the batteries and assigned to position '1'. Position 2 is just as good as off in my setup. Not sure who did this and why it was done this way...
     
  3. Creekwood

    Creekwood Well-Known Member GOLD Sponsor

    Apr 26, 2009
    Oakville and Georgian Bay, Ontario
    '97 330 Sundancer
    2X 454 w/ vDrives
    Its probably impossible to say how its wired since at some point a prior owner could have rewired things or even replaced one of the switches. But you should be able to do some sleuthing by disconnecting one of the batteries and then testing all switch combinations to see where power goes. then do then same with the other battery. Tedious, but will give you your answer.
     
  4. QT1

    QT1 Member

    322
    Oct 20, 2016
    Belair, MD
    1988 300 Weekender
    5.7 Mercruisers, Avon rib w/ Yamaha outboard
    The only dumb question is a questioned not asked! Sorry BV, I have had the same question about my boat but it's obvious it has been rewired with a different battery switch (previous owner(s).
     
  5. Black Valkyrie

    Black Valkyrie Member

    411
    Jul 19, 2014
    Canada
    1993 Sundancer 270 DA
    Twin 4.3
    So I'm going to have to climb down there with a meter and test to see what is What? Unfortunate. Thanks for the responses!
     
  6. QT1

    QT1 Member

    322
    Oct 20, 2016
    Belair, MD
    1988 300 Weekender
    5.7 Mercruisers, Avon rib w/ Yamaha outboard
    I have 3 batteries and I still dont know which does what. Life is short. I figure as long as I keep them charged and replaced every few years, I'll keep rollin!
     
    captscottc likes this.
  7. Kevin Kidd

    Kevin Kidd Member

    41
    Oct 16, 2017
    California Delta
    270 Sundancer 2000
    7.4 Mercruiser w/ Bravo 3 outdrive
    I have a question regarding the battery switch. We have a 2000, 270 Sundancer, The switch on our boat reads "off", "1", "both", and "2". Naturally if I have it set to "off" I still get a current to my bilge pumps, but cannot start the boat or turn on the house lights. I read somewhere else, that you should have the switch set to "1" or "2". If its set to "both" its too much work on the alternator, and will wear it out faster. Any truth to this? The first few times we took the boat out I had it set on "both", now I set it on "1" or "2".
     
  8. Black Valkyrie

    Black Valkyrie Member

    411
    Jul 19, 2014
    Canada
    1993 Sundancer 270 DA
    Twin 4.3
    You're asking my question (almost)

    One setting is the starter battery, the other is the house battery. It's a mystery to me which is which
     
    Kevin Kidd likes this.
  9. Kevin Kidd

    Kevin Kidd Member

    41
    Oct 16, 2017
    California Delta
    270 Sundancer 2000
    7.4 Mercruiser w/ Bravo 3 outdrive
    Yes, almost. But I'm curios as to having the switch set to both and taxing the alternator.
     
  10. Little Ducky

    Little Ducky Active Member

    691
    Jun 5, 2017
    Chattanooga TN/Dickson TN
    1998 SeaRay 290 Sundancer
    Twin EFI 5.0L w/Alpha 1 drives
    I had a 260 with 2 batteries and one switch 1,2, both, off. I would always run/cruise on both but if I was going to be on the hook for hours/overnight I would select either 1 or 2 so I would not drain both. I could start on either and run the house on either.

    My current 98 290 has 3 batteries and 2 battery switches. The battery switches only have 2 positions. On and Off so I assume each bank is separate. The bank with 2 batteries are for port ignition and house power. The bank with one battery is for starboard ignition and port ignition when using the emergency power switch.
     
    Kevin Kidd likes this.
  11. trflgrl

    trflgrl Active Member SILVER Sponsor

    899
    Jun 23, 2014
    Middle Tennessee
    1989 Sundancer 300
    Twin 350 Merc/Alpha 1 Gen 1; Quicksilver 4.0 gen
    Am I understanding correctly you have 2 batteries and 2 battery selector switches?
    We have a 3 battery arrangement but our process should work, regardless.

    Due diligence with a voltmeter would be best, but the following shortcut worked for us to get a decent idea without doing yoga in the ER. It's manageable solo and goes faster with a helper: ensure boat is on ship power only. Turn off all switches in cabin/cockpit and turn both battery selectors to the Off position. Assess (and document) what still works--lift a float switch in each bilge area to make sure all sump pumps are wired directly. Turn on other items one at a time to see if they work; I assume engines won't start, but try them.

    According to the manual, in yours the bilge pump(s), CO monitor, and mercathode should be powered when the battery selector switches are in the Off position. (This is how we identified our bilge pumps are wired directly, but our integrated CO monitor isn't.)

    Next, leaving 2nd selector in Off position, turn main selector to position 1 and repeat the process, documenting what fires. I assume only one engine will start, plus house systems.
    Turn main selector to position 2, repeat.
    Turn main selector to All, repeat.
    Theoretically, the same systems will fire with selector in position 1 or 2 as well as All; one of the numbered positions may act like Off if this switch is connected to only 1 battery. (Our multi-position switch connected to a single battery behaves this way--the number 2 position is blank/not connected to anything.) If it really is connected to both batteries, you should get the same behavior in all three positions)
    If you have an emergency start switch, use that to attempt to start the other engine.

    Now turn main selector to the Off position, turn 2nd selector to On, and repeat. I assume the 2nd engine will start, but house systems won't.
    Again, use the emergency start switch to attempt to start the first engine.

    If you find that your house systems are split between the two batteries--or that there's no difference in what operates no matter which switch is On, decide whether you want to leave everything that way. We found that our stereo was wired to what we hoped was an isolated engine starting battery, so we moved it to the house side.

    It sounds like excessive wiring/switching to have a multi-position AND a 2 position selector with only 2 batteries. A single multi-position selector would do the job, and I'd follow Little Ducky's description of how he managed his 2 battery setup by selecting either 1 or 2 while on the hook, to preserve one battery for starting.

    If you determine your multi-position selector has capacity, and you have the physical space to do it, you could upgrade and add a 3rd battery. Then you could create a "dedicated" starting battery situation on that side: we use position 1 for starting and 2 while on the hook.

    We ended up labeling our selector switches A and B, then labeling each battery with the letter of the selector that directs it. A is a multi-position tied to a single battery so that battery is A; B is tied to 2 batteries, so those are B1 and B2 corresponding to the selector switch positions that draw from each.
     
  12. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    There's good info in a couple posts above about how to go about determining what battery goes with which switch - it's really pretty straight forward. Disconnect a battery, then turn the switches on one at a time while monitoring a 12V accessory. Easy - about a 5 minute job.

    Charging two batteries is not bad for the alternator. Each battery will charge a little slower, obviously, but there are no issues with doing so.
     
    Last edited: Feb 11, 2018
  13. QT1

    QT1 Member

    322
    Oct 20, 2016
    Belair, MD
    1988 300 Weekender
    5.7 Mercruisers, Avon rib w/ Yamaha outboard
    Kevin, I have never heard of additional strain on the alternators by having all batteries on at the same time. Where did you get this info from?
     
    Kevin Kidd likes this.
  14. Henry Boyd

    Henry Boyd Well-Known Member PLATINUM Sponsor

    Apr 24, 2007
    Newburyport, on the peaceful and serene Merrimack
    02' 280 DA
    496 w BIII
    This is for stock wiring!!!, if a prior owner has changed it, all bets are off.

    In case you don’t know, NEVER mess with the switch with the engine running. Yes, the electrical system will survive switching between both and 1 or 2. It will not survive if you go through the off position with the engine running. Yah I know your all gonna say that your too smart to do that, and I’m going to reply, and what about your idiot bother?

    With this setup you have two batteries. I don’t know the orientation of yours, but for discussion’s sake let’s assume the length of the batteries lies parallel to the longitudinal axis and the batteries are also parallel to each other. Now assign the moniker “1” to the starboard battery and “2” to the port.

    Now:
    “Off” is all batteries disconnected, with the exception of essential systems, co detector, bilge pumps etc. Also although the boat can not draw power from the batteries in this position, if you have the boat plugged into shore power and the “converter” switch on, both batteries will Still charge. In fact, converter when on charges both batteries irrespective of switch setting.

    “1” brings battery 1 on line and 2 is off, “2” is the reverse.

    “Both” has the effect of placing both batteries in parallel and in doing so it doubles the available amperage. Great for hot days when good ole big block would rather snooze.

    Now we have to kill a myth. There is no such thing as a “house” battery on a Sea Ray. Both batteries are wired equally to both engine and hull systems household items like lights and entertainment, head system etc. Some boats do have batteries isolated, but SRs don’t. Spend some quality time with your wire diagram and you’ll see.

    What this means is, with your big block you are better off starting and running the boat on “both”. Because the position of the switch effects the alternator output, running on both charges both. And yes your alternator, if it is the oem, or oem spec replacement, will charge both batteries.

    And that highlights that both batteries should be the same, and ideally when they are replaced it is done with an equal pair. Long term this insures both batteries will be charged to the highest level. This is important because the charging system shuts down as soon as a battery reaches a full stage. So if one battery is at 90 percent and the other at 40 you can see what happens. But if it is 90 and 85 percent, no harm no foul. This may have lead to the notion that the both position wouldn’t charge the batteries.

    Use the 1 or 2 setting when anchored. This protects you from running both of them flat. We use 1 on odd days of the month, and 2 on even.

    Now on a twin engine boat, sea ray wires one engine with two batteries just like the single engine boats, and the other engine has its own battery. In this case there Still isn’t a house battery in that the paired batteries are wired into the whole system, and the single battery is wired only to it’s engine.

    That is the stock system. I do know that it was not uncommon for dealers to have an option that bridged the batteries to allow either to start the either engine. In that case the lone single battery would have the capability of feeding the non ignition systems as well.

    Henry


    Never mind, should have read to the end of the thread
     
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  15. Richard N

    Richard N New Member

    23
    Sep 29, 2017
    Southern California
    270 Amberjack 2007
    Achilles LT2 dinghy
    6.2 Mercruiser w/ Bravo III Drive
    From my 270 Amberjack 20180125_223240.jpg manual,
     
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  16. Black Valkyrie

    Black Valkyrie Member

    411
    Jul 19, 2014
    Canada
    1993 Sundancer 270 DA
    Twin 4.3

    Nice... even your manual doesn't tell you what 1 or 2 does.
     
    Kevin Kidd likes this.
  17. Kevin Kidd

    Kevin Kidd Member

    41
    Oct 16, 2017
    California Delta
    270 Sundancer 2000
    7.4 Mercruiser w/ Bravo 3 outdrive
     
  18. Kevin Kidd

    Kevin Kidd Member

    41
    Oct 16, 2017
    California Delta
    270 Sundancer 2000
    7.4 Mercruiser w/ Bravo 3 outdrive
    I can't remember, but it was from another boating blog I found online. I assumed if it was true, there would be a warning some place on the boat or in the manual.
     
  19. JVM225

    JVM225 Well-Known Member

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    My old boat had 3 batteries and 2 switches.
    Only things that worked with both switches set to off were the bilge pumps. That’s how it should be.
    Starboard motor had two batteries and a multi position switch with 1, 2, Both, Off. This started the starboard motor and ran all 12 volt stuff on the boat (House Bank). All 12 volt stuff worked in all positions except “Off”.
    I always ran the boat with it in the “Both” position. Once I dropped the hook for the day I switched to either “1” or “2” to run the 12 volt creature comforts. Wanted to make sure that if I ran down the one battery the other was still charged up. I tried to alternate which battery I used every day I spent in the hook. Switched it back to the “both” position when it was time to leave.
    The single battery on the port motor only started that motor.
    To identify which is battery 1 and which is battery 2 is easy.
    Put the switch in position 1, turn on the stereo, disconnect one of the batteries on the multi battery bank. If the radio stops playing then the disconnected battery is 1. If it keeps playing then the battery that is still connected is 1.
     
  20. atrick

    atrick Member

    82
    Mar 4, 2017
    Penna
    1995 searay 290 Sundancer
    1990 21 maxum
    Twin 4.3 mercrusers with alpha one drives
    305 chevy with a alpha one drive
    The radio test might not work as a lot of radios have two hots one for normal operation and one for memory, learned that the hard way as I tried your test and my memory hot wire was to the port battery and the other was to to #1 starboard and if either was disconnected the radio wouldn't work!
     

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