Wiring for Dedicated Charger & Alternator Charging

  • June 22, 2011 10:53 AM
    Message # 627727
    Deleted user
    Our rebuild is nearing completion and I'm trying to wrap up the ER wiring.  Can someone help me with the connection of a dedicated charger (Xantrex), Inverter (Xantrex) and the engine-driven alternator (100 amp on a Betamarine BV1505)?   My questions fall into two categories:  First, charging at sea is obviously via the alternator.  Since the alternator output is AC, do I go through an ACR then into the battery banks directly, or is there some other system that I'm missing?  Second, charging while moored on shore power feeds directly into the charger, then into the house and start banks.   Do I attach the charger output and the ACR output on the same battery terminal or is there some sort of automatic switching that will select the battery input?   I'm getting lost here and every time I think I understand it I uncover another question?   Anyone have a good, simple schematic?  -Tom Koehl
  • June 22, 2011 1:36 PM
    Reply # 627850 on 627727
    Anonymous
    Tom, mine is wired so that the battery charger output is wired directly to the battery...on my charger there are "outputs" for both banks that are independent of each other.
    The alternator is wired to the battery selector switch in such a way that the alternator charges whichever battery is currently selected. 
    I do not use an ACR which would enable me to charge both batteries at the same time.
    For the inverter you will have to install a breaker or fuse to protect the inverter on the DC side, this should be outlined in the manual.
  • June 22, 2011 2:01 PM
    Reply # 627883 on 627850
    Deleted user
    Gary Burton wrote:Tom, mine is wired so that the battery charger output is wired directly to the battery...on my charger there are "outputs" for both banks that are independent of each other.
    The alternator is wired to the battery selector switch in such a way that the alternator charges whichever battery is currently selected. 
    I do not use an ACR which would enable me to charge both batteries at the same time.
    For the inverter you will have to install a breaker or fuse to protect the inverter on the DC side, this should be outlined in the manual.
    Gary,

    Okay, I'm good with the inverter, and the Xantrex charger can handle three banks (starter, house 1 and house 2) directly, but you run the alternator output to the battery selector swx?  I'd love to see the schematic - do you have one?  Any reason not to use an ACR in the swx output line?
  • June 22, 2011 7:27 PM
    Reply # 628132 on 627727
    Anonymous
    Tom, it is simply wired to the common positive on the selector switch....this is also the common dc positive bus.
    There is no reason not to use an ACR, for my purposes what I have works fine and is very simple.
  • September 10, 2011 6:33 AM
    Reply # 695991 on 627727
    Deleted user
    Thomas Koehl wrote:

    Our rebuild is nearing completion and I'm trying to wrap up the ER wiring.  Can someone help me with the connection of a dedicated charger (Xantrex), Inverter (Xantrex) and the engine-driven alternator (100 amp on a Betamarine BV1505)?   My questions fall into two categories:  First, charging at sea is obviously via the alternator.  Since the alternator output is AC, do I go through an ACR then into the battery banks directly, or is there some other system that I'm missing?  Second, charging while moored on shore power feeds directly into the charger, then into the house and start banks.   Do I attach the charger output and the ACR output on the same battery terminal or is there some sort of automatic switching that will select the battery input?   I'm getting lost here and every time I think I understand it I uncover another question?   Anyone have a good, simple schematic?  -Tom Koehl

    Tom: The 'output' of a alternator is DC not AC. While it is true a alternator does generate AC internally first, the AC is then redirected to '2' one-way diodes that cause the 'output' to DC.


  • September 09, 2012 9:52 PM
    Reply # 1068313 on 627727

    This post is probably too late to answer any of Tom's concerns, but I'm pretty sure it will provide insight for a few others. I've been procrastinating over rewiring my primary DC electrics for the last couple of years and have finally run out of sideline projects to divert my attention. Kind of ironic as I'm a degreed electrical engineer. Nevertheless I constantly encounter the same dilemma Tom mentions, contradadictory information from various sources, lack of information on fully integrated systems, incomplete tracing of existing circuitry, etc. Some of the sticky points for me are the desired degree of isolation between engine start battery and house bank, I'm leaning toward the old fashioned method of a 1 2 Both switch not because I dislike the convenience of battery combiners/isolators but it seems that troubleshooting, when necessary, would be simpler without them. Also, do I tie my wind gen and multiple solar power outputs to a terminal block or follow the manufacturers recommendation and go right to the battery post. Along with the remote sensing from the Xantrex Tru-charge and a battery temp sensor or two it's going to get pretty crowded down there. Other questions concerning externally regulated alternators and lightning/bonding/SSB grounding come to mind as well. Finally, getting to my point, I found a link today that led me to more than one answer although it may have generated some new questions.

    http://www.midcoast.com/~aft/index2.html

    From the homepage there is a link at the left for Schematics. Several different boats(most larger than ours) and systems, enough to get the general flavor and makeup of modern, professionally designed, integrated marine electrical layouts. 

    By the way, I did find Jack Webb's schematic on the Perkins 4-108 wiring which I found to be most helpful, thanks Jack.

    scott 

  • September 10, 2012 10:02 AM
    Reply # 1068798 on 627727
    If you want good information, generic but clearly described, I recommend the book.


    For example, the book shows several ways to wire up alternator, switch, batteries and chargers, and discusses the relevant issues.

  • September 10, 2012 11:07 AM
    Reply # 1068860 on 627727
    Anonymous
    When rewiring our boat from scratch I read a lot of material on how and why to wire a boats DC systems. 

    I decided to direct all charge sources (alternator, solar, wind, etc) to the house bank and then connect the house bank to the starter bank via an echocharge (though an ACR would be fine too).   This allows me to never worry about the alternator losing its connection during operation and burning out diodes.  It is also more efficient since typically the house bank is the one that needs charging while the starter bank loses only portions of a single amp during engine cranking. 

    Some tips/tricks I learned in doing this is to use not only the conventional 1/2/B switch, but also a simple ON/OFF switch. 

    I have our boat configured so the ON/OFF switch handles all the "normal" stuff.  When you get to the boat, turn it on.  When you leave the boat, turn it off.  The 1/2/B switch handles the starter bank.  You just basically leave it on position 1.  If the starter bank ever dies, turn it to position 2 to crank off the house bank.  If you ever need to run the house electrics off the starter bank, turn it to B and turn the house switch to OFF.  Very simple and nothing to screw up.  This setup allows independent bank isolation in event of a dead short while still allowing flexibility.  It also sets the boat up to be "idiot" proof.  

    The 1/2/B switch is in the engine room itself since it should only be tampered with in the event of failure to start, while the ON/OFF switch is in the cabin and easy to access to promote its use.  

    http://i1121.photobucket.com/albums/l518/svsundowner/120701MajorWiring21.png

    Also see: 
    Last modified: September 11, 2012 6:08 AM | Anonymous member (Administrator)
  • September 11, 2012 6:22 AM
    Reply # 1069592 on 627727
    Anonymous member (Administrator)
    Lot of good ideas here - I recommend/use Calders book also - and for sure your alternator always needs a load to keep from being fried  (if the alternator doesn't have a load the output is redirected to the input and the voltage rises w/o control -- frying the diodes)

    Interesting the Beta wiring loom / kill switch allows you to turn off the key - before shutting down the engine -- which if I read the schmetic correctly does not provide a load on the alternator.  

    Also for mulitple batteries on a bank - check out isolators  - so a good battery doesn't try to "charge" a "bad" battery until both batteries are flat!

    Look up triple state chargers -- these are made to control the battery charge - some are very fancy and also have battery temperature sensors to prevent over charging.  

    Then there are also devices to combine/control  the output of your alternator, wind generator and solar panels to maximize the system and prevent over/under charging of the batteries.... 

    It gets pretty complicated but is well worth the effort and saves purchasing new batteries over time. 

    I'd start with the Caulder book - it's good read. 
    Jay