What would cause a motor to drain a battery while under way???

patriotspatriots Member Posts: 7
I have a 2005 Rinker 300 Fiesta Vee with twin 5.0 liter Volva Pentas with 120 hours on them. This issue just started this year. My port motor will die off while under way. When I go to start it, the battery clicks as if it is a dead battery. I put the battery switch over to bypass and the engines starts and remains running. My both alternators are putting out 14.5 volts and when I check my batteries they read at 13.5 volts. I just installed a new house battery and a new starboard battery. With everything shut down on the boat and it hooked up to shore power, my voltage at my panel only reads 11.5 volts. I have also repalced the battery isolator. Need help 

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Answers

  • Handymans342Handymans342 Member Posts: 10,375 ✭✭✭✭✭
    Sounds like battery charger. 
  • patriotspatriots Member Posts: 7
    We tested the charger and it was cycling fine.. We put a meter on to test it and it was doing what it was suppose to. 
  • LaReaLaRea Member Posts: 7,505 ✭✭✭✭✭
    Dies while underway?  It sounds like the alternator isn't delivering enough current to run the engine.  If so, the engine will run for a while by drawing current from the battery, but eventually it'll drain the battery and the engine will die.

    My guess is a loose or corroded cable connector, or a failed alternator.
  • Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    Bad battery. Get ot load tested. You should always replace them in pairs. 


    Past owner of a 2003 342FV
    PC BYC, Holland, MI
  • MarkBMarkB Member Posts: 3,960 ✭✭✭✭✭
    Either bad battery or bad alternator.

    Boat Name: King Kong

    "Boat + Water = Fun"

  • andydandyd Member Posts: 849 ✭✭✭
    I would look at the alternator first. LaRea is on the right track. Batteries store electricity for starting, etc., but it's the alternator that provides the current to keep everything running and the battery topped up.

    Andy
  • MarkBMarkB Member Posts: 3,960 ✭✭✭✭✭
    Andy on my dodge caravan my battery was dying while I was on the road. Alternator was fine but battery wasn't holding charge. The engine still gets power from the battery so if it can't hold charge it stalls.

    Boat Name: King Kong

    "Boat + Water = Fun"

  • patriotspatriots Member Posts: 7
    I would like to thank everyone for their help with this issue. You people are great. It turned out to be a couple of things, one was a bad battery and the other was a bad battery switch. My boat has two of the and I need to replace one of them . I can not locate the same style of battery switch that I have. Does anyone know where I can get a new switch to match the other one...
  • Cableguy GregCableguy Greg Member Posts: 5,011 ✭✭✭✭✭
    Can you provide a picture of the switch? There were different brands used over the years, so a picture will help a lot.
    2008 280 Express Cruiser, 6.2MPI, B3, Pittsburgh, PA "Blue Ayes"
    Go Steelers!!!
  • Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    IMO BD has it - battery won't hold a charge - that's an easy test to perform....battery load test.
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