[honest mark]

replaced my battery charger, which fried at the end of last year, replaced 4 house batterys and 4 starter batterys, all 800cca, but still have to use my battery parallel to start boat?? do you think this is normal? have twin 660hp cummins qsm11 ? did not have generator on and was not plugged into shore power, they launched me from marina, i normally do both when im at dock, what do you think??

[TIARA44]

replaced my battery charger, which fried at the end of last year, replaced 4 house batterys and 4 starter batterys, all 800cca, but still have to use my battery parallel to start boat?? do you think this is normal? have twin 660hp cummins qsm11 ? did not have generator on and was not plugged into shore power, they launched me from marina, i normally do both when im at dock, what do you think??

Hi,

I have QSM-11's on my Sovran.  My engine bank has 5 batterys - no problems cranking.  Did you go with Gells or AGM's on the new batterys?  QSM-11 electronics can be sensetive to low voltage.

Ken

[Misdirection]

I dont think what your experiencing is normal. I suspect that your experiencing voltage loss somewhere between your battery bank and the solenoid or starter. The first thing I would do is get a volt meter and measure voltage at the starter while cranking on one bank, and then with the parallel switch on. That will tell you alot. Then start checking cable connections and cleaning them and checking the crimping. Also check the ground at the engine.

Report back what you find.

Sent from my SM-A505U using Tapatalk

[honest mark]

UNDER THE STEPS IN MY BOAT ARE 3 BATTERY SWITCHES, HOSUSE, STARTING AND INTERLOCK, IF I TURN ON ALL 3 MY BOAT STARTS PERFECTLY EVERY TIME, IF I DONT USE THE INTERLOCK BATTERY SWITCH THE PORT SIDE ENGINE WILL NOT ROLL OVER AND START, IF THAT MAKES ANY SENSE, DO YOU GUYS USE YOUR INTERLOCK BATTERY SWITCH WHEN STARTING YOUR BOAT?? ONCE THE BOAT STARTS UP I TURN OFF THAT SWITCH, PLEASE ADVISE, THANK YOU.

[ReelMagic]

I haven't needed to use the interlock switch ever on my 2003 38 Open. I suspect one or more of your batteries need to be replaced or your port engine starter needs to be looked at. Additionally, I would make sue all connections on the port motor are clean (no corrosion)..

[honest mark]

yes i just got all new batteries, the boat originally was in saltwater and i know sum off the connections may be corroded, any specific connections you would check first?? or where to begin? thanks you guys...

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im thinking it may not be the starter bcuz when i use interlock it starts right up? i will check all connections...

[jclark003]

If one motor starts fine and the other is problematic there is a good chance it is the connection at the starter terminal, engine/starter ground or the battery disconnect switch terminal. If you lean on the starter without using the interconnect you may fine the problem by feel. Usually poor connections get hot quickly when passing a few hundred amps across them. alternatively as Misdirection advised, checking voltage at the starter (while starting) and then working backward across the bank will also help isolate the problem. When the voltage jumps you've passed the point of high resistance. Just make sure charger is off.

I would clean every terminal and ground wire just to be certain. Make sure to turn off charging system and disconnect the batteries before cleaning the starter terminal and exercise caution not to cross the positive and negative terminals on any battery.

Good luck

[honest mark]

I CLEANED OFF AND WIRE BRUSHED ALMOST ALL OF THE CONNECTIONS AND STILL HAVE A PROBLEM STARTING THE PORT BATTERY WITHOUT THE HELP OF THE BATTERY INTERCONNECT SWITCH UNDER THE STAIRS , WITH THAT BEING SAID, UNTILL I CAN LOCATE THE PROBLEM AM I HURTING THE BATTERIES/CHARGER OR ANYTHING ELSE IF I USE THAT INTERCONNECT TO START THE BOAT EACH TIME?? AFTER THE BOAT STARTS I TURN THE SWITCH OFF?? I ALSO START UP THE GENERATOR FIRST, THEN THE BOAT, IS THAT THE CORRECT SEQUENCE YOU GUYS USE, OR WOULD YOU START BOAT WHILE ITS STILL HOOKED UP TO SHORE POWER, THEN START GENERATOR?? THANK YOU GUYS FOR HELPING.

[jclark003]

The interconnect is just a mechanical parallel switch so you should be ok using it for starting purposes. Out of curiosity does the parallel switch not start the engine as well?

I would start the port engine first, then open the interconnect switch, then start the starboard engine. That way you don't have two alternators working against each other. If the engine will start without the charger that would be best. Generator really doesn't matter one way or another.

I would be remiss not to point out that problems like what you are describing tend to get worse over time and take a bite out of a seemingly good day at the worse possible time. hope you are able to find it and get it worked out.

[honest mark]

if i use the battery parallel they start up perfect also....