Blue Seas Add-A-Battery Questions

[baccus06]

1996 StarCraft 2010BR/5.7l Mercruiser/Alpha 1

I wired up my starting battery and everything runs off of that battery for now until I get my second battery installed. First question is how do I isolate the house load to the new second battery? I want to be able to have the radio and everything run on battery 2 so that the cranking battery doesn't get drained while on the water. Second question is do I need to add in line fuses to my batteries with this kit, and if so, where do they go? the directions didn't give any information about the fuses. Thanks

 

[UncleWillie]

Re: Blue Seas Add-A-Battery Questions

You will move the House loads to the new battery usually by moving the cable that supplies power to the fuse panel over to the new battery.

There are NO in line fuses between the batteries and the Battery Switch.
There ARE Fuses in line with the ACR as show in the Instructions.

 

[baccus06]

Re: Blue Seas Add-A-Battery Questions

first those are not the instructions that came with my kit. mine had 1 column of English and the rest in other languages so thank you for that link. Second, my boat was not wired for a second battery to start with. I found the wire that runs from my switches at the helm to a breaker on the top of the engine. when I disconnect that, none of the switches work. I do not have a fuse panel at all that I can find, unless those switches are what you are referring too. I am not very knowledgeable with electric work. this is the only picture of the helm I have at this time if it helps.

 

[baccus06]

Re: Blue Seas Add-A-Battery Questions

and here is a picture of what is going on so far.

 

[bruceb58]

Re: Blue Seas Add-A-Battery Questions

The big problem with moving the entire fuse panel to the house battery is that you will also be moving the fuse that supplies the ignition circuit it's power. You have to make sure that is moved back onto the engine battery. That may require a separate fuse panel for anything engine related.

 

[UncleWillie]

Re: Blue Seas Add-A-Battery Questions

The big problem with moving the entire fuse panel to the house battery is that you will also be moving the fuse that supplies the ignition circuit it's power. You have to make sure that is moved back onto the engine battery. That may require a separate fuse panel for anything engine related.

Is it really an issue?
The ignition circuits commonly see less than 10 volts during cranking.
Unless the house battery was extremely dead, (<9v) it should have enough to power the ignition and pull in the starting solenoid. 30 seconds after engine start, the ACR closes and the ignition is running off both batteries and the alternator as usual. If the house battery was extremely dead, switching the battery switch to BOTH, solves the problem as intended.

That boat is sophisticated enough that it will have a fuse panel.
Lay down on the deck and look up under the dash. It will be up there somewhere.

 

[bruceb58]

Re: Blue Seas Add-A-Battery Questions

If for some reason you left the lights on completely and had a completely dead house battery, I wouldn't want to rely on the combine function of the switch for me to start. If the house battery was drawn down enough that it's very dead, you really don't want to be combining in the first place. What would happen if the house battery actually failed completely?

Not that hard at all to separate the ignition system power so that it is on the start battery. It's the correct way to do it. You want engine all on one battery and the house loads on the other. If you don't want to separate them, just get a 1/2/both type switch.

 

[UncleWillie]

Re: Blue Seas Add-A-Battery Questions

I agree it is the Right way to do it.
I just wonder how many people actually make the effort and I suspect the the original 1/2/Both switches never get replaced either in the case where two batteries were installed before the ACR installation.

I am surprised that a separate engine/ignition fuse block is not mentioned in the ACR instructions.
I suspect it would scare off many potential customers.
The ignition on the house battery is not ideal, but it is better than the ignition on the ONLY Battery.

 

[baccus06]

Re: Blue Seas Add-A-Battery Questions

ok so I know I need to find the fuse panel. When I do, what is next? I know of one wire that runs to the breaker on the top of my engine from under the helm switches. How do I actually split the house load and engine circuits? That is where I am confused.

 

[UncleWillie]

Re: Blue Seas Add-A-Battery Questions

This is where the can of worms gets opened.

The current fuse block has ALL the loads attached to it. There are two large wires (12v, GND) running back to the main battery, Likely 10ga or larger, attached through a 30 amp fuse at the main battery.

To properly separate the engine from the house, you will need to duplicate the current fuse block with a new House Fuse Block and all the wiring and fuse, back to the new house battery, and then move all the house circuits over to the new House Fuse Block.

This is the reason the side discussion on how many people actually preform the house/engine split became started.

It is the technically correct way to do it but it is debatable if it is worth the effort.
Unless the house battery goes so dead it will not even toot the horn, it is not needed.
The alternate, less messy option, is to add another battery switch to be able to disconnect the house battery in the rare event you left the electronics ON for an overly extended period. OR... Just remove one cable from the House Battery and switch the ACR Battery switch to BOTH.
Not all that difficult unless you tend to kill your house battery often.

 

[bruceb58]

Re: Blue Seas Add-A-Battery Questions

TThis is the reason the side discussion on how many people actually preform the house/engine split became started.

That's why I didn't do it on my Wellcraft and did do it on my pontoon boat. On my Pontoon boat it was easy to separate.

If the boat wasn't designed for a house in the first place, it is often more trouble than its worth to separate them later.

Instead of moving all the house loads to a new fuse block. Just move the ignition over to a new fuse block with a feed from the motor.

Or, just move the heavy hitters like stereos and lighting to the house battery side of the switch with a separate fuse panel for those few items.