Wiring a dual battery setup 2006 21i

[stevewood]

I currently have a starting battery only and want to install a house battery with a 120 amp ACR. Any suggestions on where/how to feed the cables to the batteries? And install the 120 ACR.?

Then the wiring for the power to new sound system.

[chpthril]

Are you looking for advice on how to physically run the cables or schematically run the cables? Where are the batteries going to be located. Where is the switch going to be located. What kind of switch and ACR do you have? Whats the scope of the audio system?

[stevewood]

Existing battery located in rear of boat under small seat from factory, I am thinking the other battery to be located under opposite seat. Yes physically it's a challenge to get wiring through this location then up to console.
I have a pair of tower wet sounds db8 and a ht2 amp and will be adding a pair of 60's in the near future and then some interiors with another amp.

[stevewood]

Pleas see my post I'm a complete newbie posting thread comments, sorry.

[Lewisville]

I am thinking about doing the same thing. Attached are two different wiring diagrams I have seen on wb.com, any suggestions on which is best? What batteries are you using? I have a 24 series Interstate marine cranking battery 135 capacity 1000 amp at 32degrees and haven't decided on the second but leaning towards a deep cycle 24 series.

[chpthril]

Lewisville,

Without knowing exactly what type of "Isolator" is being represented in those illustrations, its impossible to comment on their validity. That could be a simple dual-battery switch, or a diode type, and ACR or VSR or even a simple heavy duty continuous-duty solenoid. Although there are a handful of best-practices and a lot of commonalities between different battery schematics, there is no one size fits all diagram. The scope of the stereo and other house loads, how you intend to use the system, the total amp hours of the house battery bank and more, will all play in to the design of the battery bank and charging system.

Regardless of what that isolator is, im not liking the right hand diagram.

[Lewisville]

chpthrill, You are talking straight over my head. I was thinking of using the left diagram and a simple battery switch, but then I would have to monitor both charges to know when to switch each to the alternator. How do you feel about that idea? Is there an isolator type that will do the monitoring and direct the alternator power accordingly? I'm not running an insane stereo, just two 7" tower speakers, 6 61/2" boat speakers, normal head unit, 2 amps 1000watt and 600watt, and 1 10"sub which makes me wonder if it is worth the hassle or if I could live with one battery and a good alternator?

[chpthril]

I was thinking of using the left diagram and a simple battery switch

This does make it simpler, but neither diagram is ideal for a traditional OFF/1/BOTH/2 switch. If you stick with the plan, we can assist with a diagram.

but then I would have to monitor both charges to know when to switch each to the alternator.

Not when wired correctly. With a traditional dual battery switch, all loads can be wired to the common post. This has all loads drawing off what ever battery the switch it turned and that battery also receives a charge when the engine is running.

Is there an isolator type that will do the monitoring and direct the alternator power accordingly

Yes there is. An ACR ( Auto Combining Relay) will allow both batteries to receive a charge when the engine is running. The dual battery switch will keep the batteries and their loads isolated from each other when at rest.

makes me wonder if it is worth the hassle or if I could live with one battery and a good alternator

Yes, its worth it to have a dual battery setup.

[Lewisville]

chpthrill, can you post an ideal diagram for an OFF/1/2/All switch?

[chpthril]

Electrical flow wise, this diagram is accurate. ALL loads, except the brown/red auto-bilge lead will come off the B+ post of the original battery and relocate to the C post of the switch. Exactly how you amps are wired, in regards to cable size, fused distribution/non-fused distribution, etc, can be addressed as more info become available. The amp's GND cable can connect to either battery, which ever is closer is the best.

[Lewisville]

chpthrill, Thank you. If the switch has 1/2/C(All?) do you use the manual reset breaker as your off?

[chpthril]

The amp;s main trunk line needs a main form of circuit protection as it leaves the battery. This is to protect the boat from a rare but possible short in that trunk line, if one ever did occur. I prefer to use a manual reset breaker as opposed to a traditional automotive amp fuse holder, especially in boats where the batteries are in the bilge.engine bay. With all loads, including the amps, terminated to the common post of the switch, tuning the switch to off will isolate both battery banks from those loads. The breaker is just there as protection.