Marlin300 Battery Wiring

ttles714

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My 2001 Marlin had a Starting battery for each engine.. and 2 house batteries in parallel. 3 battery switches , starboard engine, port engine, house on and off. My new to me and laid up for winter 2007 Marlin has 2 battery switches and from what I have read the house batteries are tied into one of the starting batteries.. and somewhere the diesel Generator starter and steering power assist, are tied into one of the engine batteries...

My initial thoughts were that the older boat had a better configuration ..Is my thinking wrong??.. I am looking for comments .. Has anyone changed this configuration on the newer boats ( I think from 2003 ?? >>) ?
 

Fishtales

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Not sure if I agree with better, it was different. My guess is with the options - generator, thruster, ac, microwave and other big draw items it was cleaner to have two versus three banks. A good question for GW.
 

journeyman

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ttles714 said:
I am looking for comments .. Has anyone changed this configuration on the newer boats ( I think from 2003 ?? >>) ?

The previous owner of my Marlin added 2 house batteries and mounted them behind the generator. I was told that because there was concern of the potential load on the system and he fished overnight offshore a lot, he felt it necessary to beef it up. It took me a while to understand the set up but I think I have a handle on it. The weight of the batteries at the stern doesn’t change the attitude of the boat much as I had a bow thruster installed when I bought the boat and that has another dedicated battery up at the bow. The 2 additional batteries are wired to the 50 amp DC breaker in place of the factory house batteries which frees up the 4 factory batteries to be dedicated to the engines except for power to the windlass motor, power assist and for starting the genny. I have a 65 amp 3 bank Charles battery charger. A new battery switch was added which, when off, isolates the new house batteries from the factory batteries and when switched to on, ties them to bank 1. So when the new switch is off, the starting batteries aren't being run down by house load. While underway, the motors only charge the factory batteries but by switching to on, the new house batteries get a charge if needed. Kinda slick really. When I bought the boat, the new house batteries were big AGMs. I replaced all my batteries this year and went with all dual purpose as I didn’t like the idea of mixing battery types when and if the banks were switched together. Also, they were something like 800 bucks apiece. I’m too much of a cheap French Canadian for that!

I know it's probably overkill but it works and I don't think I'll ever be short on juice with this set up.
 

ttles714

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Thats an interesting set up .... I don't think I need to go that far... somewhere in the back of my mind, On my list of to do projects, that I am sure my wife will not understand!!!! I was thinking about Isolating the 2 house batteries from the two engine batteries ... That's what I liked about the older set up .. If i killed the house batteries, the engines would always start strong !! I think on this new set up they have Isolated ONE of the motor starting batteries .. I need to spend some time looking more closely at it ...
 

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My 265 had 2 starboard side batteries as house/stbd starting and 1 port starting battery.
2 Switches allowed starting from either or both but house was only the stbd side batteries.(pain in the a.. because you have to remove tubs from both sides to access switches...stupid)
The Aux charging wires from the motors connected to the starting wires, effectively not using the Aux.

My plan is to dedicate stbd side batteries as House and have 2 starting batteries in the port side one for each motor
I will route the stbd motor start wire to the port side and the port Aux charging wire to the stbd side.
House (2 parallel dual purpose) charges from Aux charging wires from both motors.
Each motor charges its starting battery through its starting cable.

Switches will allow starting from any or all. Looking to relocate switches for access thru doors or under gunnels
Replaced 40A push button reset breaker with one that also acts as on/off switch so I can shut off House.
Going to separate the hardtop box feed from house with its own feed and breaker so if house pops, I don't lose ALL electronics (have backup gps and vhf on other circuit).

(I had a bad connection on that 40A breaker and went dark in the dark 90 miles out. Luckily I new the circuit and figured it out in a few minutes)
 

ttles714

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I would love to look at a schematic as to how you are going to wire them ... What motors do you have? My ox66's had a separate charging lead for the house batteries which was isolated withing the motor ... I thought that was a great Idea ... I could be wrong, but I do not believe my F250's have that feature.
 

Scott D

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I redid the battery switch panel and the configuration in my 04 Marlin last year. 3 banks using 4 batteries.

Details here. Pics no longer showing up for some reason

http://www.greatgrady.com/forum/viewtopic.php?f=3&t=24619

I think this is the best most foolproof way to do it. I never think about it or move switches. It just works well.
 

ttles714

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Thats pretty much what I would like to have .... 2 starting batteries , 1 port , 1 starboard,.. and 2 house batteries in parallel.. I would tie the Gen into one of the starting batteries and the Power assist to the other ... All other functions, House and Electronics on the 2 house batteries ..