Wiring Diagram for Blue Sea Add A Battery (Switch + ACR Combo)

This post is to document how to properly wire a three battery system in conjunction with a Blue Sea Add A Battery combo (http://bluesea.com/category/2/productline/overview/329) and a ProSport20 Dual Bank onboard battery charger (http://www.pmariner.com/productFeatu...oductNum=42020). Hopefully, this will give someone the confidence to do the install themselves. I thought it would be helpful to show the wiring diagram in three stages as it can get pretty confusing. This is the set up I have which I ran the past two summers without a hitch. I wil post some pics of my install later this week when I finish my current rewiring project.

So below is step 1, which is wiring the switch and the batteries. Note that stereo batteries 1 and 2 are wired together (in parallel) so they act like one, big 12 volt battery. Also note that the 4 pole Dual Circuit Plus Switch is very different that the three pole Perko switch that is commonly installed on our boats. The Dual Circuit Plus is like two separate switches in one housing and does not have a common post like the Perko does.

The idea is to wire all the stereo related stuff to the stereo battery bank via one side of the switch, and the starter and the helm buss to the starting battery via the other side of the switch. When the switch is in the ON position, both sides of the switch are closed, and are separate. In the OFF position, both sides of the switch are open so everything is dead. In the COMBINE position, both sides of the switch are closed and connected together so both batteries are feeding all the electrical loads.

Note that I show suggested wire sizes but I do not show any fuses but they must be installed as specified by the equipment manufacturers.

http://i250.photobucket.com/albums/g...3367/Step1.jpg

Step 2 is shown below, in which the Blue Sea ACR is added. Note that a jumper is added between the neg post of stereo battery 1 and the neg post of the starting battery.

The ACR automates the switching process so that you just set it to ON and forget it. When the ACR senses that either battery is receiving a charge from the alternator (in this case, the starting battery), the relay closes so that the charging current is also sent to the stereo battery bank. It does this once it senses 13.0 Volts for more than 2 minutes. So essentially, the relay closes two minutes after the engine is started. Once the engine is off and you are cranking your stereo, once the ACR senses that the batteries combined voltage has fallen below 12.75 Volts for 30 seconds, the relay opens, isolating the batteries. So now your stereo is only draining the stereo bank and you won't accidentally drain your starting battery.

Note that the ACR will not close if either battery bank is less than 10.8 volts. Doing so would cause the batteries to equalize, which means you now have two discharged batteries instead of one.


http://i250.photobucket.com/albums/g...3367/Step2.jpg

Step 3 is shown below, which shows the addition of the onboard dual bank smart charger. The ProSport20 is a 20A dual bank smart charger and can send up to 20A to the bank that needs it most. However, since the ACR will detect the charge and it's relay will close, both banks will receive the charging voltage equally and in essence, defeats the purpose of the smart charger. So it's important that a 100A resettable circuit breaker is installed between the ACR and each battery so that the breaker can be opened during onboard charging operation to disable the ACR.

Sorry if this is too much information. I think it will help once you see the pics of my actual install.
http://i250.photobucket.com/albums/g...3367/step3.jpg

Holy crap, Al! That is fantastic, but I'm sure glad I'm looking at this in the morning with a cup of coffee vs in the evening with a few beers!

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Originally Posted by wolfeman131

Holy crap, Al! That is fantastic, but I'm sure glad I'm looking at this in the morning with a cup of coffee vs in the evening with a few beers!

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I know, there's a lot of wires going every which way, and a lot of info to absorb!

David at Earmark,

I know you have done tons of these installs so could you please do us a favor and (1) review my wiring diagram and let us know if you see any errors and (2) let us know if there is a different way to wire this up that would result in operational improvements, and what those improvements are.

Thanks in advance.

Al

Al, bad question on my part but what does it do? blue sea stuff

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Originally Posted by moombadaze

Al, bad question on my part but what does it do? blue sea stuff

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Stacy,

Please see step 2 in my original post above but in simple terms, the ACR automatically isolates the starting and stereo batteries when the engine is not running so that if you are playing your stereo, it is only draining the stereo battery. And when you start up the engine, it’s only using the starting battery. After your engine has been running for about two minutes, the ACR will combine both batteries so that both batteries are getting charged by the alternator. So all you have to do is set the switch to “ON” and forget it.

Without an ACR, you have to do this manually by switching the Perko switch to battery “2” when the engine is off, to “1” when you are getting ready to start the engine, and to “Both” after the engine is running. If you forget to switch it to “2” and you are hanging out at party cove for an extended period of time cranking your stereo, you could drain both batteries and not be able to start the engine.

Hope that helps.

Al

Al,
Pertaining to the Blue Sea equipment, you have it wired the way that the manufacturer suggests. This is a complex category. Our approach to this category uses different equipment (same switch but different voltage sensing relay) and our scheme will change according to the boat type (whether the stereo is dependent on the helm buss for touch screen controls or can be wired totally independent), the amount of current draw from the audio equipment and the amount of reserve time for the stereo batteries. One of the largest problems with ACR/VSRs is they don't combine after a long period at rest with a large stereo so the stereo bank isn't brought on line with the alternator as expected. Not a problem if you are going straight home but a definite concern if its a long weekend with no AC access. So we have schemes to confront the problems of systems becoming too large and exceeding the functional limits for which the ACR/VSRs were originally intended. This category should not be generalized with a one scheme fits all approach.
Contact me via email so I can learn more about what equipment you have or will have, your total battery reserves and how you will use the system and boat most weekends. At that time I can make some suggestions that will be specific to only your sysyem. Give me a little time as its crazy this time of year.
[email protected]

David
Earmark Marine

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Originally Posted by cab13367

Hope that helps.

Al

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sorry, I reread the whole thing from the start and saw that--sorry to make you reword it again. Quess the drawings kinda overwhelmed me and I didnt read it word for word.

Sounds like a awesome system that when I can I might just go with something like that

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Originally Posted by EarmarkMarine

Al,
One of the largest problems with ACR/VSRs is they don't combine after a long period at rest with a large stereo so the stereo bank isn't brought on line with the alternator as expected.

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Davis,

Thanks for the reply and I will e-mail you about my specific system. In regards to the above statement, the product literature says that the ACR will not combine if one of the battery banks is showing less than 10.8V in order to protect the other bank. Is this what you are referring to? So as long as I don't deplete the stereo bank below 10.8V, the ACR should combine two minutes after it senses charging voltage (above 13.0V), again, per the literature. Does it not work like this in the real world?

Thanks,

Al

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Originally Posted by moombadaze

sorry, I reread the whole thing from the start and saw that--sorry to make you reword it again. Quess the drawings kinda overwhelmed me and I didnt read it word for word.

Sounds like a awesome system that when I can I might just go with something like that

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No problem. I realize there is a lot of info here to absorb but I think it's important to understand how the system works.

Al,
Its just not that simple.
You can have over 11 volts but if the ratio of depleted reserves in amp/hours is large enough combined with the continued stereo draw that is large enough the voltage will drop like a rock and the Blue Sea will open again. This isn't a problem for minor systems but is a real world challenge with BIG systems when you cross a threshold in stereo size and stereo battery bank reserves.
Having 200 amp/hours at 80 percent (11.5 volts) depletion is far more challenging than having 65 amp/hours at 100 percent (10.5 volts) depletion. Its more an issue of current versus voltage. Voltage is just the consequence.
Seriously depleted batteries can be a real liability to the charging system and the ACR/VSR operation.
Like I said its complex and a moving target as systems become larger.

David
Earmark Marine

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Originally Posted by EarmarkMarine

Al,
Its just not that simple.
You can have over 11 volts but if the ratio of depleted reserves in amp/hours is large enough combined with the continued stereo draw that is large enough the voltage will drop like a rock and the Blue Sea will open again. This isn't a problem for minor systems but is a real world challenge with BIG systems when you cross a threshold in stereo size and stereo battery bank reserves.
Having 200 amp/hours at 80 percent (11.5 volts) depletion is far more challenging than having 65 amp/hours at 100 percent (10.5 volts) depletion. Its more an issue of current versus voltage. Voltage is just the consequence.
Seriously depleted batteries can be a real liability to the charging system and the ACR/VSR operation.
Like I said its complex and a moving target as systems become larger.

David
Earmark Marine

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Thanks David. I think my system is more in the moderate category but I did send you an e-mail with the details of my system and look forward to hearing your thoughts on improving my set up, if necessary.

At a minimum, it sounds like I need to install a digital voltage gauge at the helm to keep an eye on the stereo bank battery voltage.

Al

I spoke to David and he shared with me a slightly different wiring scheme that eliminates the need for a resettable breaker between the ACR and the battery. In my set up, I have the ACR wired directly to the battery with an inline resettable breaker on each leg. This allows me to open the breakers and isolate the ACR when I have the onboard smart charger hooked up.

With David’s scheme, the ACR is wired to the output posts on the switch instead of directly to the battery. So when it’s time to charge the batteries, you can put the switch in the OFF position and the ACR will be isolated. This accomplishes the same thing as opening the breakers in my scheme. It’s a more elegant solution that mine since it does not require additional components (the resettable breakers).

Hope that makes sense. This is only relevant if you are going to charge your batteries with a smart charger.

Below is a revise schematic showing David’s scheme in red.

Thanks David for sharing this with me.

Al



http://i250.photobucket.com/albums/g...maticDavid.jpg

Great write up & sketches are definitely worth a thousand words, etc. I'd been scratching my head on how to incorporate a dual bank charger with a battery switch/VSR combo. Thanks.

I only have 90 rated amps of stereo, one Optima blue primary battery, one Optima blue stereo only battery, a Blue Sea Dual Circuit Plus Switch, and a SurePower 1314-200 VSR. I picked up a 140A alternator (more than I need, but the price was too good to pass up). Rather than upgrading the wiring in the old harness, I'm thinking of running an additional wire to help carry the load. If I wanted to land a second feed (properly sized & fused, of course) directly off of the alternator output, where should it tie into the last diagram?

It should land on the pos terminal of the starting battery. Newty upgraded his alternator so you might ask him what he did.

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Originally Posted by cab13367

It should land on the pos terminal of the starting battery. Newty upgraded his alternator so you might ask him what he did.

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Actually, the power feed from the alternator goes to the starter and is connected to the 2/0 cable that connects the starter to the starting battery. This is how the alternator current goes back to the starting battery. So if you want to add an additional cable, I would run it back to the starter.

Thanks, Cab. Forgot to mention this is on an old Supra Saltare. While I love my Supra forum brothers, I found your diagram & ya'll seem to be bit more electrically inclined over here.

I traced the alternator feed wire (looks to be 10 or 12 ga) back to the engine loom. From there, it wye's into one wire headed up to the helm and one to the 50 amp breaker. It jumps from the breaker to the starter solenoid & then to the starter where it would tie into the same terminal as the battery cable back to the primary battery. Should I bypass the breaker and solenoid & go directly to the starter? Just upgrade the wiring along the same path (won't I risk popping the 50A breaker with a 140A alternator)? Or land directly to the primary battery, or battery switch, or VSR? Now I've gotten myself totally confused??

I'm really not qualified to advise you on this. We are getting a little over my head now. All I know is that if you want to run a feed back to the battery, you definitely want to land it on the battery, not the switch or vsr. The vsr will sense the charge and combine your batteries when appropriate so both batts will get charged.

Thanks cab for the diagram... did my set-up last night. Made things a lot easier and quicker than trying to understand all the lines without a diagram. Only difference was I went with the ProMariner 20 3 Bank charger than your set-up. Everything worked so far in the garage, I guess I'll find out tomorrow if I get any feedback with my amps and such as some people get. Thanks again!

Quote:

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Originally Posted by bbuhtz

Thanks cab for the diagram... did my set-up last night. Made things a lot easier and quicker than trying to understand all the lines without a diagram. Only difference was I went with the ProMariner 20 3 Bank charger than your set-up. Everything worked so far in the garage, I guess I'll find out tomorrow if I get any feedback with my amps and such as some people get. Thanks again!

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Great! Glad to know it helped you out.

For anyone following my wiring diagram, please see post #22 of the link below for an important change regarding where to connect the ACR Starter Isolation (SI) wire.

https://forum.moomba.com/showthread....653#post147653

Quote:

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Originally Posted by cab13367

I spoke to David and he shared with me a slightly different wiring scheme that eliminates the need for a resettable breaker between the ACR and the battery. In my set up, I have the ACR wired directly to the battery with an inline resettable breaker on each leg. This allows me to open the breakers and isolate the ACR when I have the onboard smart charger hooked up.

With David’s scheme, the ACR is wired to the output posts on the switch instead of directly to the battery. So when it’s time to charge the batteries, you can put the switch in the OFF position and the ACR will be isolated. This accomplishes the same thing as opening the breakers in my scheme. It’s a more elegant solution that mine since it does not require additional components (the resettable breakers).

Hope that makes sense. This is only relevant if you are going to charge your batteries with a smart charger.

Below is a revise schematic showing David’s scheme in red.

Thanks David for sharing this with me.

Al



http://i250.photobucket.com/albums/g...maticDavid.jpg

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Sorry to be dredging up such an old post, but I'm curious...can this layout from David be used even if you don't have an onboard smart charger installed yet? I can't see any reason why not but I'm mechanically, not electrically, minded!!

Thanks