House Battery-gctid361053

[Guest]

Can you move everything but the starter to the house battery? Looks like in the mercruiser 4cyl wiring diagram that wire #6 (red/purple) feeds everything and is attached to the starter solenoid off what looks to be some sort of fuse. I was thinking of just moving that #6 wire to the house battery which looks like it would put the fuse panel/gages and everything else on the house one. Also if that is the common way whats the best way to extend that to the battery compartment? Solder and crimp with heatshrip wrap or maybe a anderson type plug like a sb50 (http://www.andersonpower.com/products/multipole-sb.html)?

Attached files [img]/media/kunena/attachments/vb/664030=25400-3-16-2012 3-46-05 PM.jpg[/img]

[Guest]

tbkohl will be the man to answer this EXACT question, as he added a second battery, and, made a stackable battery tray in your very model. I dunno if it any info is still in the Epic BR thread. I can take a look/search....

[Guest]

10 pages and my eyes are burnt. Looks like it was Macgyver that originally did the stackable battery. He is know longer with us. Nothing morbid. That guy was a God in terms of modifications. I wish his pics would have survived.

I don't know if anyone copied the idea. I believe it was just a 1 x angle iron frame for a Group 24 or 27 battery w/legs.

Really makes me wanna dismantle that monster.....:surr

[2850Bounty]

qbayle wrote:
1... Can you move everything but the starter to the house battery?

2... Looks like in the mercruiser 4cyl wiring diagram that wire #6 (red/purple) feeds everything and is attached to the starter solenoid off what looks to be some sort of fuse.

3.... I was thinking of just moving that #6 wire to the house battery which looks like it would put the fuse panel/gages and everything else on the house one.

You are not the first to ask this question. And many of the larger boats are set up similarly.

NOTE: your schematic is not all inclusive. It pretty much shows only a few portions of the engine harness, and the ignition key circuits.

There is a whole bunch more to this that receives power from the "common" cable and engnie harness interface at the starter motor, and all of this plays a part in what your question involves.

1 & 3... Yes, you sure could, and I assume that there'd be no MBSS.... correct?

But there's a penalty for doing so which I'll explain.

2... Yes, not only powers everything, this is how the OEM harness is able to charge the battery...., or the battery that is selected at the time.

But I doubt that this boat came equipped with an MBSS, but you could certainly add one.

Here's what may help you:

The #6 that connects to the starter motor main lug is part of the engine harness. This interfaces with the helm harness, of which eventually feeds and powers most everything..... including what it takes to power your instruments, blower motor, starter motor solenoid, ignition, etc.

(this would be minus the typical direct battery connection that the Power Trim Pump or Trim Tabs may use)

This is also the same circuit that allows the alternator to charge what you're calling the House battery.

If you take this engine/helm circuit away from the OEM starter motor connecting point, the alternator may still charge the original start batt, but will no longer charge what you're calling the House Bank.... there'd now be no path to it!

Everything including the Ignition, oil pressure gauge, temp gauge, blower motor, will be drawing from a bank that NOW does not have an alternator in the loop.

House Bank gets low..... engine starts to stumble... and you can see where we're going here.

Several scenarios:

A.... Bluseas's system that does all of this automatically for you. It will allow all house loads to be from the house bank, it will charge both battery banks via an ACR.

Start battery will be dedicated to cranking only.

B... go ahead and take the hull harness away from the engine interface, connect to a separate House Bank, and use the ACR to charge this now completely separated House Bank.

Start battery will be dedicated to cranking only.

C... go ahead and install your second battery bank, use an MBSS to select between the two, leave the OEM harness as is, and then take the alternator charge lead out of the loop, and install a Bluesea ACR between this and the two battery banks.

Now you can select either battery, and charge either battery simultaneously with the alternator.

Your helm power will come from which ever battery you have selected.

Start battery will be dedicated to cranking only, but you will be the one managing banks.

.

[Guest]

2850Bounty wrote:
You are not the first to ask this question. And many of the larger boats are set up similarly.

1 & 3... Yes, you sure could, and I assume that there'd be no MBSS.... correct?

But there's a penalty for doing so which I'll explain.

2... Yes, not only powers everything, this is how the OEM harness is able to charge the battery...., or the battery that is selected at the time.

But I doubt that this boat came equipped with an MBSS, but you could certainly add one.

Here's what may help you:

The #6 that connects to the starter motor main lug is part of the engine harness. This interfaces with the helm harness, of which eventually feeds and powers most everything..... including what it takes to power your instruments, blower motor, starter motor solenoid, ignition, etc.

(this would be minus the typical direct battery connection that the Power Trim Pump or Trim Tabs may use)

This is also the same circuit that allows the alternator to charge what you're calling the House battery.

If you take this engine/helm circuit away from the OEM starter motor connecting point, the alternator may still charge the original start batt, but will no longer charge what you're calling the House Bank.... there'd now be no path to it!

Everything including the Ignition, oil pressure gauge, temp gauge, blower motor, will be drawing from a bank that NOW does not have an alternator in the loop.

House Bank gets low..... engine starts to stumble... and you can see where we're going here.

Several scenarios:

A.... Bluseas's system that does all of this automatically for you. It will allow all house loads to be from the house bank, it will charge both battery banks via an ACR.

Start battery will be dedicated to cranking only.

B... go ahead and take the hull harness away from the engine interface, connect to a separate House Bank, and use the ACR to charge this now completely separated House Bank.

Start battery will be dedicated to cranking only.

C... go ahead and install your second battery bank, use an MBSS to select between the two, leave the OEM harness as is, and then take the alternator charge lead out of the loop, and install a Bluesea ACR between this and the two battery banks.

Now you can select either battery, and charge either battery simultaneously with the alternator.

Your helm power will come from which ever battery you have selected.

Start battery will be dedicated to cranking only, but you will be the one managing banks.

.

Perfect! Thank you and nice write up!

I wasn't planning on putting in a selector switch, but I did pick up a battery isolator relay that I was going to put in between the two positive terminals of the batteries and power the relay part off the alternator so once the boat was running both batteries could charge.

I just wanted to make sure that moving everything else over was okay, since the way I read the diagrams it would actually take both batteries to start since the house battery would fire the starting relay and the other battery would run the starter.

I also figured I'd keep a small alligator jumper wire to jump the isolator relay if one battery was dead.

Looking at the diagrams, the red/purple does connect to the alternator but it's the sensing lead, and the orange wire is the output lead and it connects to the starter as well as the starting battery so the starting battery would always charge and the isolator/relay would allow the house battery to charge.

I'm glad I took another look at the diagrams because now I'm thinking I can't use the alternator to fire that isolator relay. I'll just have to get the volt meter out and figure how to trigger the isolator relay, maybe off the switch.

[2850Bounty]

I believe that you'll need some type of selector switch device.

One for either selecting a battery to be used for starting, and then back to the House Batt......

or,...... one that will work with a battery that has been separated from the starter motor/hull harness interface, and now needs to be selected to receive the alternator charge.

One way or the other..... you'll need a means of selecting and/or switching.

Here's a suggestion: Why not draw this out schematically and show us what you propose?

I think that once you see this in schematic form, it will make more sense to you.

Include the starter motor main lug, how the engine harness connects to it, how the alternator also connects to it, and how the hull harness connects at this same point and goes forward.... and then how you would like to separate out the House Loads.

I removed some wiring from a basic schematic for you...... maybe you could modify it to show what you want to do.

I'm a dummy with this, and I just use MS Paint. You can use the tools and move things around, cut, copy, import, etc.

The New House Circuits panel was drawn up for the larger boats.... you can delete that..... or show it as your helm panel.

If you don't want the MBSS or the ACR, just delete them.

Attached files [img]/media/kunena/attachments/vb/664134=25412-MBSS Single engine blank.jpg[/img]

[Guest]

Okay here's what I've got cooked up so far.

Steps:

1. Mount house battery

2. Connect house and starting battery grounds together

3. Move red or red/pur lead from starter to house positive

4. Take lead from start battery positive to one pole of isolator relay

5. Take lead from house battery positive to other pole of isolator relay

6. Connect ground of isolator relay to start or house ground

7. Disconnect red/pur from ignition switch

8. Run new power lead from start battery to red/pur terminal of ignition switch

9. Connect positive of isolator relay to pur (exciting) terminal of the ignition switch

Attached files [img]/media/kunena/attachments/vb/664156=25420-dual battery.jpg[/img]

[Guest]

You could also just leave all existing wiring in place, add the house battery with isolator relay and run new fuse panel from house battery right next to exiting fuse panel and move over the things you want on the house circuit like radio, gps, fish finder, and lights. After I had this thought I may go this route, not sure. I do like the idea of keeping the wire harness wired the way it is in the manual.

[2850Bounty]

First of all, I'd not bring a wet cell battery and a gel cell battery together as you are doing. The charge rate and final voltage are not the same.

Plus, you won't get the Amp Hours from a Gel Batt that you will from a good wet cell Deep Cycle battery.

Steps:

1. Mount house battery

2. Connect house and starting battery grounds together

3. Move red or red/pur lead from starter to house positive

4. Take lead from start battery positive to one pole of isolator relay

5. Take lead from house battery positive to other pole of isolator relay

6. Connect ground of isolator relay to start or house ground

7. Disconnect red/pur from ignition switch

8. Run new power lead from start battery to red/pur terminal of ignition switch

9. Connect positive of isolator relay to pur (exciting) terminal of the ignition switch

Some of these I'm not following you on.

1... a given

2... I'd not. We want each bank to make it's own separate and redundant System Negative Common connection (engine), IMO.

3... where/how does this receive alternator charging?

4... the battery isolator relay joins the two banks together while the ignition key is ON only...... is that correct?

If so, where is the division or separation for an alternator to sense each bank individually?

6... again, I'd use the system negative common.

7... please explain this one.

8... how do you plan to disrupt this when the boat is unattended?

9... exciting the side of what?

I don't want to burst your bubble on all of this, but I think that you're complicating things beyond reason, given what I think you are attempting to achieve by doing this.

If you were to install an MBSS, you can achieve the same thing.... but you must manage your battery banks, keeping #1 in "reserve" during your anchor time and radio use, etc.

Switch back to #1 for engine cranking, and be on your way.

Or... install an MBSS and a heavy AMP version of an ACR or VSR, and keep your MBSS on #2. Then let the ACR/VSR bring the "Start Batt" into the loop while cranking.... and you don't need to even touch the OEM wiring to add this system.

Or..... use the Blueseas system which does all of this for you.... and again, you don't need to even touch the OEM wiring.

KIS .... keep it simple.... or KISS... keep it simple silly!

.

[Guest]

2850Bounty wrote:
First of all, I'd not bring a wet cell battery and a gel cell battery together as you are doing. The charge rate and final voltage are not the same.

Plus, you won't get the Amp Hours from a Gel Batt that you will from a good wet cell Deep Cycle battery.

Some of these I'm not following you on.

1... a given

2... I'd not. We want each bank to make it's own separate and redundant System Negative Common connection (engine), IMO.

3... where/how does this receive alternator charging?

4... the battery isolator relay joins the two banks together while the ignition key is ON only...... is that correct?

If so, where is the division or separation for an alternator to sense each bank individually?

6... again, I'd use the system negative common.

7... please explain this one.

8... how do you plan to disrupt this when the boat is unattended?

9... exciting the side of what?

I don't want to burst your bubble on all of this, but I think that you're complicating things beyond reason, given what I think you are attempting to achieve by doing this.

If you were to install an MBSS, you can achieve the same thing.... but you must manage your battery banks, keeping #1 in "reserve" during your anchor time and radio use, etc.

Switch back to #1 for engine cranking, and be on your way.

Or... install an MBSS and a heavy AMP version of an ACR or VSR, and keep your MBSS on #2. Then let the ACR/VSR bring the "Start Batt" into the loop while cranking.... and you don't need to even touch the OEM wiring to add this system.

Or..... use the Blueseas system which does all of this for you.... and again, you don't need to even touch the OEM wiring.

KIS .... keep it simple.... or KISS... keep it simple silly!

.

Thanks for the reply.

[2850Bounty]

Perhaps something like this.

Attached files [img]/media/kunena/attachments/vb/664613=25513-QBayle Battery schematic.jpg[/img]

[Guest]

"but I think that you're complicating things beyond reason, given what I think you are attempting to achieve by doing this. "

I agree. From a wiring/electric load standpoint, our boats are probably very similar. I installed an extra battery and selector switch two years ago. All I really needed was a spare battery that I could use when the engine wasn't running. I just installed the new battery, connected the ground, connected the existing battery and the old battery positives to posts 1 &2 of the MBSS, and then connected the existing main load lead to the common post of the switch.

Normally, I use the original battery to start the engine, and then move the switch to "Both" so both batteries will charge. If I am running accessories with the engine off, I switch to second battery.

[Guest]

Personally I don't think it's complicated, I just don't want a switch. Everything runs off the house battery, starting is done by the starting battery and when the alternator is turning they two batteries are combined and being charge. Simple really and a 150amp continuous use relay costs $22 vs a add a battery kit for $150 and with the add a battery you have to install a switch (which makes it more complicated). The blue sea ACS is just a isolating relay.

Look at the installation of the blue sea acs, I'm doing the exact same thing minus the combining switch.

http://bluesea.com/files/resources/instructions/990170140.pdf

The only thing the switch gets you is a quick way to combine the batteries if the starting one is dead, well and they want to sell you a switch.

The marine relay I bought for $22 is 150/300A and the Blue sea ACS one is only 120/210. I guess I'm just cheap, lol. I really do appreciate all the input I think bouncing ideas back and forth usually produces good outcomes. In this case when I drew it out I realized I had to move the power that goes to the ignition switch from the stock harness to the starting battery or otherwise the relay would be on all the time.

The other funny thing is I'm having a hard time figuring out how to actually get the second battery mounted so I'll probably going to save this project for next year. I've got a bunch projects going now that I'm hoping to get posted later in the completed projects thread.

[2850Bounty]

You say that you're doing the same thing.

As I see it, you're NOT actually doing the same thing if you start taking the OEM hull harness/engine harness interface apart and changing it around.

Again, I see no need to do this.

A continuous duty solenoid (if I understood you) will not provide what an ACR or VSR will provide.

You'll find that there are different takes on this, but I'm not one who likes the idea of both banks (of which are Un-Like batteries) being charged while combined.

Unlike meaning; different battery size, different types (cranking vs deep cycle), different groups, different number of cycles, etc.

The ACR or VSR does a much better job at this.

Your call on that.

I will agree........ an MBSS does require that you pay attention and be vigilant regarding managing your battery banks.

I always suggest; learn it, get used to it, and make it work like the thousands of the rest of do.

If you don't like the switching, check out what Bluseas has to offer in their automatic systems.

There's really no need to take the OEM hull harness/engine harness interface apart for what you are wanting to achieve.

These are all suggestions only. I wish you the best of luck with it.

.

[Guest]

2850Bounty wrote:
You say that you're doing the same thing.

As I see it, you're NOT actually doing the same thing if you start taking the OEM hull harness/engine harness interface apart and changing it around.

Again, I see no need to do this.

A continuous duty solenoid (if I understood you) will not provide what an ACR or VSR will provide.

You'll find that there are different takes on this, but I'm not one who likes the idea of both banks (of which are Un-Like batteries) being charged while combined.

Unlike meaning; different battery size, different types (cranking vs deep cycle), different groups, different number of cycles, etc.

The ACR or VSR does a much better job at this.

Your call on that.

I will agree........ an MBSS does require that you pay attention and be vigilant regarding managing your battery banks.

I always suggest; learn it, get used to it, and make it work like the thousands of the rest of do.

If you don't like the switching, check out what Bluseas has to offer in their automatic systems.

There's really no need to take the OEM hull harness/engine harness interface apart for what you are wanting to achieve.

These are all suggestions only. I wish you the best of luck with it.

.

My reasoning behind moving the ingnition wiring is so that starting the boat does not require both batteries. If you do not move the power to the ignigtion switch over to the starting battery then it will be the house battery that fires the starting relay. Maybe this is where the ACR comes into play then, not sure but with just the isolating relay this should be done or there really isn't a point if it takes both batteries to start.