New Battery Help

[Seacraft06]

On my new to me Pathfinder I am still learning the wiring layout. Boat has four batteries and one Prosport three bank charger. 

I have two West Marine Dual Purpose group 27 batteries in the console. I am pretty sure these are isolated to run the trolling motor only. Each battery is hooked to a charging bank on the prosports

In the transom I have two Interstate group 27 cranking batteries. These are hooked up to the Perko selector switch. Switching being a 1, both, 2, off. One of the batteries has leads coming from the third bank on the prosports charger. I am pretty sure it is rigged so that one battery is the cranking and the second is the house battery. 

Here lies my questions:

I am replacing the two Interstate batteries. I am looking at going with the same batteries as in the console. Will these dual purpose batteries be a better fit? I also want to make sure this battery is a good fit for my 2010 Yamaha F150. Batteries: http://www.westmarine.com/buy/west-m...91?recordNum=7 The reverse capacity on the battery is lower than what the Yamaha manual says....

Or, am I better off going back to two regular cranking batteries?

My thought is going with the dual purpose allows my electronics to benefit from them being deep cycle and I can still use either one to crank the motor? Electronics remain on when I am either stopped fishing, diving or at the sandbar. The electronics are minimal though. Garmin 94sv, radio, lights.

[Bamaskeet]

I think this might be a good time to go to a three battery setup.  I would suggest you put three group 27 or 31 deep cycle in the console.  This reduction in weight in the stern will help your boat perform better.  

Two batteries run your trolling motor, the third battery is your cranking battery and wire it so one if your trolling motor batteries is the backup for your cranking battery.

Look around the forum, Hobo published a wiring diagram for this setup.

 

 

[SCFD rtrd.]

This sounds like a better idea. Less weight, less batteries and less cost. And the three bank charger will charge all three batteries. This is how my boat was set-up from the factory.

[Fish Food]

What Bamaskert said, but use AGM batteries, AGM are often called Dual Purpose but function fine for cranking if you have the correct amount of cranking amps and works well for the TM. 

[brew1891]

possible dumb question...is this set up possible with a 36v trolling motor system?

[FunFlatsFishing]

I have mine set up this way as well. AGM is definitely the way to go. 

Check out the 27 series Duracell at SAMs Club. Great price. 

 

Brew - it wouldn't be advisable to run that set up with 3 batteries because as you wear down the one battery that is being shared with the "house", it will begin to canabalize the others. 

[Fish Food]

Brew,

That is what I have on my boat. Four batteries, four bank charger, same concept for a 36v TM, one house/starter, 3 for TM and one of the TM batteries as a back up for a starter.

 You can search for a diagram for that set up.