House/Start Battery Question

[Patman941]

Picked up my new to me boat yesterday and ran into some difficulties with the batteries and need some help.

The boat has a killer JL Audio system with 3 subs! Way more than I need, LOL. 3 batteries to support as well.

Yesterday while anchored on the water I turned the engines off and tried to listen to some tunes. I left the house switch “on” and turned the start switch “off”. As soon as I did that it killed all power to the boat. So In order to listen to music I had to leave both switches in the on position, which made me a bit nervous, as I didn’t want to kill the batteries and be dead on the water. What am I doing wrong here? Any help is always appreciated.

 

[Dixie Highway]

Is there a DVSR (auto parallel switch) that separates the two banks? If so you shouldn’t be in danger of draining the start (unless the PO did something like hook amps or something to the start battery). I don’t think the SX came stock with dual batteries so they were probably added in later. Likely the stereo head unit is powered by the original wiring which was all from one bartery (start battery). Need more info to confirm though.

 

[Weeb]

you actually bought a 2016 242 didn’t you. With the start battery off and the house on push and hold the button that looks like a light bulb and the connext will come on. It’s called float mode.

 

[Patman941]

you actually bought a 2016 242 didn’t you. With the start battery off and the house on push and hold the button that looks like a light bulb and the connext will come on. It’s called float mode.

Yes it’s a 2016 242 LS. Oh fantastic! Thank you very much. I also included some photos of the batteries and amps. Im not super confident at everything I’m seeing. I am far from an audio guy, but the previous owner did a great job.

 

[Weeb]

I can’t see your ground wires on the batteries. Mine has a battery cable from the start negative to the house negative.
Once you know everything is working properly you shouldn’t have to turn off the start battery because it’s isolated.

 

[Julian]

If he has done the house battery voltage fix, then the house and start battery voltage should show correctly on the connext screen (meaning they should be different voltages). If they are always the same, then that fix has not been done. If they are different, then you can simply go out and crank some tunes and confirm later that your start battery doesn't drop much (or at all). It SHOULD be separate "stock" unless the PO did something really dumb.