what is needed to run dual batteries

[wiegs]

I want to run dual batteries so I can run my audio without having to worry the boat won't start. What all do I need to make this happen? Could someone that has done this provide me a part list?

Also would getting a better battery like Optima make a difference?

 

[mphy98]

Re: what is needed to run dual batteries

Get a battery switch like this one from I boats. Easy to install.

http://www.iboats.com/Guest-2100-Ba...8789794--**********.169040889--view_id.204738

 

[airdvr1227]

Re: what is needed to run dual batteries

I use (2) 12v batteries wired in parrallel. No switch, no isolator. But you have many choices. You can get a switch like the ones here. Once installed you decide what battery is being used, or both. What I don't like about these is you have the ability to make the wrong decision. Typically when you're out cruising you'd have the switch set to charge both batteries. Once you stop you change to using just one battery for your audio and leave the other for starting. There are a bunch of ways you could screw this up and end up with both batteries dead.

Or you can get an isolator like these. The isolator will automatically decide which battery needs charging.

Personally I think 2 12v wired together is all you really need. You'd be hard pressed to drain both batteries running your audio.

 

[ozarkt165]

Re: what is needed to run dual batteries

My marine starting is a dual post old school top post and wingnut stud side by side. Added a second top post for giggles. Bought 4 clamp on ends (top post) and used 4 gauge wire. I leave the negative off one side of the battery if i am worried about running low on juice. My battery compartment is easily accessible though, you may be better off w master switch.

 

[Silvertip]

Re: what is needed to run dual batteries

Unless you run a high power audio unit for several hours there is no issue with using a single battery provided it is a suitable size. If you do have a high power stereo and lots of other accessories with moderate to high current draw, then a dual battery switch, ACR, or isolator should be usedd. I won't describe them here as you can do that. ACR stands for automatic charge relay. There are at least 50 posts here on how to wire and use a dual battery switch so use the search function to locate those diagrams.

 

[stewman]

Re: what is needed to run dual batteries

I am very new to boating and have been wondering the same thing, i am looking to add a battery for backup power due to a large stereo system. On iboats i have found this switch and it appears to be the perfect fix for yours and my problem.

http://www.iboats.com/Battery-Distr...8132478--**********.596597623--view_id.341116

"The VSR allows for two or more batteries to be charged via the engine charging system. When the start battery reaches 13.7V the relay closes allowing the house battery to be charged. When the engine is stopped and the voltage drops to 12.8V the relay opens, isolating the start from the house battery. This prevents accidental draining of the start battery and protects sensitive electrical equipment from harmful engine start up spikes.
Clusters come completely bused and are easy to install. An ideal replacement for battery selector switches."