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Battery Isolator Installation Question


Roush611

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I am in the process of purchasing an 01 Waksetter that has an older system installed. The first thing I want to do is add a second battery that is solely for the stereo. I have purchased a stinger sgp 32 isolator but am a bit confused when it comes to installing it. I think this is the correct diagram, my question is can the 12v source be the alternator?

1BD9FAC3-B1B6-4715-B782-B074A501DFB8_zps

 

Edited by Roush611
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Although im not a fan of these setups in boats, for a few reasons, yes, that diag is basically correct electrically. I prefer a manual dual bank switch as opposed to just a heavy duty continuous duty relay with all the loads wired direct to a battery. 

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12 minutes ago, MLA said:

Although im not a fan of these setups in boats, for a few reasons, yes, that diag is basically correct electrically. I prefer a manual dual bank switch as opposed to just a heavy duty continuous duty relay with all the loads wired direct to a battery. 

Thank you! Any particular reason your prefer a switch over and isolator?

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A) no way to actually use the house bank for an emergency start

B) no means to disconnect amps and other stereo gear from house bank when the boat is put away. Even boat electronics are still connected directly to a battery

 

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47 minutes ago, MLA said:

A) no way to actually use the house bank for an emergency start

B) no means to disconnect amps and other stereo gear from house bank when the boat is put away. Even boat electronics are still connected directly to a battery

 

Can't you install a circuit breaker for that purpose? 

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Are you going to install a manual-reset switchable breaker for every load on the boat to disconnect everything when the boat is stored? One single battery switch and all loads are disconnected from boat banks. 

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611,

Not to the alternator output as a solenoid trigger because the alternator is permanently wired to the starting battery so the solenoid would be permanently closed. Use the switched ignition off the key.  

This is the most basic version of a battery isolator. It works but it's not ideal for the reasons listed above by MLA. Another limitation is that it offers no alternator protection in the way provided by a voltage sensing solenoid (ACR/VSR). If you had several large stereo batteries in parallel that were seriously depleted after a long duration at rest, the moment you start the boat the alternator instantly sees the full low impedance load. Not so much a risk with a moderate system on a single group 24, but a concern on the larger systems.

The Blue Sea Add-A-Battery kit is a good system because it addresses all the issues above and has a dual circuit battery switch, which is a much better fit when used with an ACR/VSR, versus a conventional dual battery switch.  

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59 minutes ago, David said:

The Blue Sea Add-A-Battery kit is a good system because it addresses all the issues above and has a dual circuit battery switch, which is a much better fit when used with an ACR/VSR, versus a conventional dual battery switch.  

+1

If you're not worried about having to use the stereo battery to start the boat, an option would be to go with just the ACR and a breaker between it and the starter battery (which you would leave closed) - and put a volt meter and shore charger on the stereo battery.  If the meter reads low (alternator has not yet topped off the stereo battery) when you get back to the dock just plug the charger in.  If voltage is OK then walk away.  No switches to worry about either way and both batteries get charged on the water and off.

https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A

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Damn it now I am confused. Ha ha So what would the difference be between running a perko and the stinger relay to the blue sea kit?  Only reason I am asking is because the relay will be here tomorrow and I have a perko laying around the house.  If I went with that set up would I run the perko to the batteries then the batteries to the isolator or am I in la la land? I also should mention, I don't know if its important, but the stereo runs off a switch on the dash.  I don't know if all the boats are like that or not.  

My main goal is to have something I do not have to worry about switching back and forth through out the day.  Then at the end of the day when the boat is out of the water just flip the perko to cut power to everything. 

Edited by Roush611
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yeah man for what you want to do, just spend the $100 and buy the blue sea add-a-battery kit.  We can post diagrams and write another 5000 words that explain why your solution doesn't work that well, but the fact is that a product is made that does exactly what you want and it only costs about $100.  Just buy that and worry about other stuff.

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55 minutes ago, Roush611 said:

Damn it now I am confused. Ha ha So what would the difference be between running a perko and the stinger relay to the blue sea kit?  Only reason I am asking is because the relay will be here tomorrow and I have a perko laying around the house.  If I went with that set up would I run the perko to the batteries then the batteries to the isolator or am I in la la land? I also should mention, I don't know if its important, but the stereo runs off a switch on the dash.  I don't know if all the boats are like that or not.  

My main goal is to have something I do not have to worry about switching back and forth through out the day.  Then at the end of the day when the boat is out of the water just flip the perko to cut power to everything. 

A perko what, thru-hull or anchor light? Sorry, just kidding. I know you mean battery switch but Perko makes thousands of marine products and their battery switches suck. Also, there are different types of battery switches that will change a wiring and use scheme, so you really need to be specific. However, I can tell you the basic difference between an ACR/VSR and a simple solenoid type heavy duty relay. The relay is either open or closed where as the ACR is voltage sensative as it has an actual processor. 

 

The dash stereo switch simply turn the head unit on and off but in your plan, all the main power cables would be battery direct with no means to disconnect. 

Your best option would be the Blue Sea dual circuit plus switch and an ACR. 

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15 minutes ago, MLA said:

A perko what, thru-hull or anchor light? Sorry, just kidding. I know you mean battery switch but Perko makes thousands of marine products and their battery switches suck. Also, there are different types of battery switches that will change a wiring and use scheme, so you really need to be specific. However, I can tell you the basic difference between an ACR/VSR and a simple solenoid type heavy duty relay. The relay is either open or closed where as the ACR is voltage sensative as it has an actual processor. 

 

The dash stereo switch simply turn the head unit on and off but in your plan, all the main power cables would be battery direct with no means to disconnect. 

Your best option would be the Blue Sea dual circuit plus switch and an ACR. 

Thank you for the explanation.  So since the system is voltage driven then I do not need to run a wire back to the ignition with this system?

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22 minutes ago, Roush611 said:

Thank you for the explanation.  So since the system is voltage driven then I do not need to run a wire back to the ignition with this system?

That's correct.  Batteries combine when voltage reaches certain level for certain period of time (IIRC 13.7v for 30 seconds); batteries separate when voltage drops.  Dead simple to operate.  

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Since I rarely (never) disconnect battery power from the rest of my boat, I just removed the Perko switch.  I don't see much benefit in the capability of being able to switch to the other battery to start it if my starting battery is dead.  If this were to happen, I would just take a couple of minutes and physically swap batteries.

Seems like a large portion of starting problems are connection related and a Perko switch just adds more of these.  A side benefit of the stereo battery not being wired to start the boat is that you can put the battery right next to your amps and run a much smaller gauge wire back to the alternator/relay/isolator because it doesn't have to carry the engine starting current.

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1 hour ago, MadMan said:

Since I rarely (never) disconnect battery power from the rest of my boat, I just removed the Perko switch.  I don't see much benefit in the capability of being able to switch to the other battery to start it if my starting battery is dead.  If this were to happen, I would just take a couple of minutes and physically swap batteries.

Seems like a large portion of starting problems are connection related and a Perko switch just adds more of these.  A side benefit of the stereo battery not being wired to start the boat is that you can put the battery right next to your amps and run a much smaller gauge wire back to the alternator/relay/isolator because it doesn't have to carry the engine starting current.

 

What isolates your batteries?  If you have no switch, do you still have a voltage sensing relay that separates them?  If not then if you just have two batteries hooked together with nothing to separate them, 99% if one battery is dead the other will be too, because what you have is one big two celled battery.

Edited by shawndoggy
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611,

I think the main issue for most of us is at least maintaining a master disconnect. So if you have a Stinger solenoid coming and you already have a dual battery Perko switch here is how you can use both.

Wire the dual battery Perko switch in the conventional manner. Battery #1 to switch position #1. Battery #2 to switch position #2. Nothing else battery-direct. The battery switch common/output post to the alternator/starter, helm buss, and all stereo equipment. Just the most basic configuration as it was intended. Now wire the solenoid across the two battery positive terminals. The solenoid will be triggered On & Off by the ignition key.

Set the battery switch to position #2 at all times when not in storage. Set the battery switch to "Off" whenever in storage.  

Battery #1 will be isolated and held in reserve whenever the engine is Off.

 

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2 hours ago, Roush611 said:

Thank you for the explanation.  So since the system is voltage driven then I do not need to run a wire back to the ignition with this system?

The blue sea 7610 ACR does not require the ignition circuit, only the ground side of the control coil. 

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1 hour ago, shawndoggy said:

 

What isolates your batteries?  If you have no switch, do you still have a voltage sensing relay that separates them?  If not then if you just have two batteries hooked together with nothing to separate them, 99% if one battery is dead the other will be too, because what you have is one big two celled battery.

A battery isolator, not this one but similar:

http://shop.pkys.com/Victron-Energy-Argofet-100-Amp-Battery-Isolator-for-two-batteries_p_3669.html?gclid=COnX3fDKxssCFUM8gQodilQK7g

 

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Getting too complicated.  KISS principle.  Connect all your stereo amps and head unit directly to the house battery.  Everything else stays as it is.

Like this:7610QuickInstall-w-BatteryCharger.png

If you are going to leave the boat unattended for months at a time and are worried about parasitic drain by the amps then add a switch between the amps and stereo (house) battery.  Forget the charger if you have a long journey back to shore during which the alternator will charge stereo (house) battery.

As I learned on the crew, it's also a good idea to run a line from the stereo (house) battery to the head unit toggle switch on the dash so the head unit is on the same battery as the amps.  You can use the other side of this wire for the "remote on" leg back to the amps.

Simple and requires you to do nothing when you start out for the day or return.

Edited by minnmarker
Mistake
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10 hours ago, minnmarker said:

Getting too complicated.  KISS principle.  Connect all your stereo amps and head unit directly to the house battery.  Everything else stays as it is.

Like this:7610QuickInstall-w-BatteryCharger.png

If you are going to leave the boat unattended for months at a time and are worried about parasitic drain by the amps then add a switch between the amps and stereo (house) battery.  Forget the charger if you have a long journey back to shore during which the alternator will charge stereo (house) battery.

As I learned on the crew, it's also a good idea to run a line from the stereo (house) battery to the head unit toggle switch on the dash so the head unit is on the same battery as the amps.  You can use the other side of this wire for the "remote on" leg back to the amps.

Simple and requires you to do nothing when you start out for the day or return.

 

Yep, that's how mine's wired, simple is good, less to go wrong.

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I forgot about the "always hot" wire that many head units have (for clock, etc.).  That should also be fed by the stereo battery.  Mine is crimped in at the hot side of the toggle switch.

While a dual charger might top off the starter battery a bit sooner (if it needs it), both batteries do get charged in this setup.

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min,

First about the always hot. For about the past 15 years or longer, head-unit have a constant B+. Its more than just clock and memory, its the circuit the head unit actually draws its operation current from. This is a result of the changes in the auto industry. If you looked at an ignition on a car lately, they are all small low current wires that send voltage triggers. Older cars and trucks had large heavy duty ignition switches with large wires in and out. all the ignition current actually passed through the switch. Those old ignition switches could handle the head-unit current through the head-units switched ign. Now a days, the ignition switches would not last tong with the same loads going through them. Head unit draws its current through a constant B+ and simply told to wake by via the low current red wire.

One issue with using a single charger in the manor above, is that a dedicated house battery and dedicated cranking battery will be cycled so differently. For this reason, a dual bank charger is best as it can evaluate, recharge and condition each battery based on its state of charge, rather than combined through an ACR. 

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1 hour ago, minnmarker said:

While a dual charger might top off the starter battery a bit sooner (if it needs it), both batteries do get charged in this setup.

you can't look at the batteries as separate in that diagram when they are on the charger, because the vsr will close and they will be combined.  They turn into one big battery.  If one cell is charged and the other discharged, the discharged cell will draw down the charged cell until they are in equilibrium.  So the starting battery might not have needed it before you put it on the charger, but it will once you do.

Edited by shawndoggy
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To put a finer point on what Shawn mentioned, which I totally agree with, those original Blue Sea diagrams reflect how ACR/VSRs where originally used. You might see ACR/VSRs used on a fish & ski or a bay boat with two banks, one for starting and one for house. The most draw might be instrumentation. The boat was returned with a full charge on both banks. The single bank small charger was for maintenance and not for charging deeply discharged banks. You would never see an ACR/VSR used on a fishing boat between the boat system and a large trolling motor bank. The trolling motor scenario is similar to today's large audio systems with larger capacity battery banks. These banks don't normally get properly charged and conditioned by an alternator on the return trip to dock. You have to adjust the charging system scheme to the present application. A dual bank charger and dual bank isolation is what's called for. I could go much deeper into the technicalities but that should be adequate reason why.     

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